Familial dysalbuminaemic hyperthyroxinemia (FDH), most commonly due to an Arginine to Histidine mutation at residue 218 (R218H) in the albumin gene, causes artefactual elevation of free thyroid hormones in euthyroid individuals.

We have evaluated the susceptibility of most current free thyroid hormone immunoassay methods used in the UK, Europe and Far East to interference by R218H FDH.Different, one- and two-step immunoassay methods were tested, measuring Free T4 (FT4) and Free T3 (FT3) in 37 individuals with genetically-proven R218H FDH.With the exception of Ortho VITROS, FT4 measurements were raised in all assays, with greatest to lowest susceptibility to interference being Beckman ACCESS > Roche ELECSYS > FUJIREBIO Lumipulse > Siemens CENTAUR > Abbott ARCHITECT > Perkin-Elmer DELFIA. Five different assays recorded high FT3 levels, with the Siemens CENTAUR method measuring high FT3 values in up to 30% of cases. However, depending on the assay method, FT4 measurements were unexpectedly normal in some, genetically-confirmed, affected relatives of index FDH cases.All FT4 immunoassays evaluated are prone to interference by R218H FDH, with their varying susceptibility not being related to assay architecture but likely due to differing assay conditions or buffer composition. Added susceptibility of many FT3 assays to measurement interference, resulting in high FT4 and FT3 with non-suppressed TSH levels, raises the possibility of R218H FDH being misdiagnosed as Resistance to Thyroid Hormone beta or TSH-secreting pituitary tumour, potentially leading to unnecessary investigation and inappropriate treatment.

Single test rule-out of acute myocardial infarction using the limit of detection of a new high-sensitivity troponin I assay.

To determine the diagnostic accuracy of a high-sensitivity cardiac troponin I (hs-cTnI) assay in patients presenting to the Emergency Department (ED) with suspected acute coronary syndromes. Specifically, we evaluated the use of a single blood test at the time of arrival in the ED, using low hs-cTnI cut-offs.
In a prospective diagnostic test accuracy study at 14 centers, we included patients presenting to the ED with suspected ACS within 12 hours of symptom onset. We drew blood for hs-cTnI (Siemens ADVIA Centaur, overall 99th percentile 47 ng/L, limit of quantification [LoQ] 2.50ng/L) on arrival. Patients underwent serial cardiac troponin testing over 3-6 hours. The primary outcome was an adjudicated diagnosis of acute myocardial infarction (AMI). We evaluated the incidence of major adverse cardiac events (MACE: death, AMI or revascularization) after 30 days. Test characteristics for hs-cTnI were calculated using previously reported cut-offs set at the LoQ and 5 ng/L.
We included 999 patients, including 131 (13.1%) with an adjudicated diagnosis of AMI. Compared to the LoQ (100.0% sensitivity [95% CI 95.9-100.0%), 99.7% negative predictive value [NPV; 95% CI 97.6-100.0%), a 5 ng/L cut-off had slightly lower sensitivity (99.2%; 95% CI 95.8-100.0%) and similar NPV (99.8%; 95% CI 98.6-100.0%) but would rule out more patients (28.6% at the LoQ vs 50.4% at 5 ng/L). MACE occurred in 2 (0.7%) patients with hs-cTnI below the LoQ and 7 (1.4%) patients with hs-cTnI <5 ng/L. Accounting for time from symptom onset or ECG ischemia did not further improve sensitivity.The Siemens ADVIA Centaur hs-cTnI assay has high sensitivity and NPV to rule out AMI with a single blood test in the ED. At the LoQ cut-off a sensitivity >99% can be achieved. At a 5 ng/L cut-off it may be possible to rule out AMI for over 50% patients.

Carotid Intima-Media Thickness is a Predictor of Subclinical Myocardial Damage in Men with Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) promotes the development of atherosclerosis and is a major risk factor for cardiovascular disease. High-sensitivity cardiac troponin I (hs-cTnI) assays fundamentally improved the diagnosis of myocardial injury and even enable the prediction of future cardiovascular events in the general population. However, data about the association of hs-cTnI with cardiovascular risk factors and carotid intima media thickness (cIMT) as a marker of atherosclerosis are limited, especially in patients with T2DM.In this cross-sectional study we analyzed clinical and laboratory parameters of 234 patients (43% women) with T2DM and a median age of 65 years (interquartile range: 57-71). The median duration of diabetes mellitus was 10 years (6-17). Anthropometric data, blood pressure, glycemic parameters and lipid profiles were determined. Hs-cTnI plasma concentrations were measured on an ADVIA Centaur XPT immunoassay analyzer and cIMT was evaluated by high-resolution ultrasound.
Hs-cTnI plasma concentrations were below the gender-specific 99th percentile in 93% of T2DM patients with a median concentration of 4.0 ng/l (interquartile range: 2.0-10.0). Hs-cTnI was significantly associated with gender, renal function and C-reactive protein in the entire study cohort. Gender-specific analyses revealed cIMT and renal function to be significantly associated with hs-cTnI in men. Contrary, only age was significantly associated with hs-cTnI in women.

In a real-world clinical setting in patients with T2DM, cIMT is a predictor of subclinical myocardial damage in men, but not in women.
Prevalence of vitamin D deficiency and its predictors in the Portuguese population: a nationwide population-based study.

Vitamin D deficiency is prevalent worldwide, but its prevalence is unknown in adult Portuguese population. In Portugal, 66% of adults present Vitamin D insufficiency/deficiency. Winter, living in Azores, older age, and obesity were the most important risk factors. It highlights the need of strategies to prevent vitamin D deficiency in Portugal.To estimate the prevalence and risk factors of vitamin D deficiency in the adult Portuguese population.Adults (≥ 18 years old) from the EpiReumaPt Study (2011-2013) were included. Standardized questionnaires on socio-demographic and lifestyle features were obtained. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were evaluated using ADVIA Centaur VitD competitive immunoassay (Siemens Healthineers) in 2015-2017 as 25 (OH)D Level 0: ≤ 10 ng/mL; Level 1: 11-19 ng/mL; Level 2: 20-29 ng/mL, and Level 3: ≥ 30 ng/mL. Weighted multinomial regression analysis was conducted to evaluate the association between socio-demographic and lifestyle variables and vitamin D status.Based on weighted analysis, the estimated prevalence of levels of 25(OH)D ≤ 10, < 20, and < 30 ng/mL was 21.2, 66.6, and 96.4%, respectively. The strongest independent predictors of serum 25 (OH)D ≤ 10 ng/mL were living in the Azores archipelagos (OR 9.39; 95%CI 1.27-69.6) and having the blood sample collection in winter (OR 18.53; 95%CI 7.83-43.87) or spring (11.55; 95%CI 5.18-25.74). Other significant predictors included older age (OR 5.65, 95%CI 2.08-15.35), obesity (OR 2.61; 95%CI 1.35-5.08), current smoking (OR 2.33; 95%CI 1.23-4.43), and female gender (OR 1.9, 95%CI 1.1-3.28). Conversely, physical exercise (OR 0.48, 95%CI 0.28-0.81) and occasional alcohol intake (OR 0.48, 95%CI 0.29-0.81) were associated with a lower risk of 25(OH)D ≤ 10 ng/mL.Vitamin D deficiency/insufficiency [25(OH)D < 20 ng/ml] is highly prevalent in Portugal, affecting > 60% of all Portuguese adults, with strong geographical and seasonal variation. This study highlights the need to critically assess the relevance of vitamin D deficiency as a public health problem and the urgent need for a wide and scientifically robust debate about the most appropriate interventions at the individual and societal levels.

Immunoassay interference on thyroid functions tests during treatment with nivolumab.

Immune checkpoint inhibitors (ICI) are associated to several endocrine side effects. In particular, the use of PD-1/PD-L1 inhibitors is related to a higher incidence of thyroid dysfunction.A 85 years-old patient, diagnosed with a metastatic melanoma treated with nivolumab, presented to our hospital with severe ICI-related thyrotoxicosis. The diagnosis was complicated by a biochemical interference on thyroid hormones assay, probably induced by nivolumab.Baseline laboratory examination conducted before the onset of anticancer therapy showed normal thyroid function test (TFTs). A few days after receiving the second nivolumab administration, the patient developed a severe thyrotoxicosis. According to destructive thyroiditis, in a short period thyroid-stimulating hormone (TSH) levels normalized and rapidly increased, but free thyroxine (FT4) levels were inappropriately elevated and did not decrease as expected. The sample was processed by using a Siemens Centaur® immunoassay. We reanalyzed the same sample at another laboratory and with a different immunoassay method (Roche Elecsys®). The results obtained from this assay confirmed severe hypothyroidism with appropriately low FT4 levels. We suspected a possible nivolumab-associated interference on the FT4 assay. Therefore, we subjected the same sample a polyethylene glycol (PEG) 6000 precipitation, a simple method for the removal of macromolecules, before assaying for FT4 levels. The evaluation of the post-PEG-precipitation sample (Siemens Centaur® immunoassay) revealed appropriately low FT4 levels. The patient was started on levothyroxine therapy, with monthly TFT monitoring using the Roche immunoassay. Approximately 9 months after starting nivolumab therapy, the patient was advised treatment cessation. A month later, the TFTs were retested on a Siemens Centaur® immunoassay, and appropriate FT4 levels were observed in accordance with normal TSH levels on adequate levothyroxine replacement therapy.We report a possible novel nivolumab-induced biochemical interference on assays of FT4 levels. The hypothesis of a biochemical drug-induced interference is further supported by the disappearance of the interference after the withdrawal of nivolumab. Further studies are needed to prove the biochemical mechanisms of this interference.

Differentiating 11β-hydroxylase deficiency from primary glucocorticoid resistance syndrome in male precocity: real challenge in low-income countries.

Congenital adrenal hyperplasia due to 11β-hydroxylase deficiency (11-BHD) and primary glucocorticoid resistance syndrome (PGRS) are two relatively uncommon causes of gonadotropin-releasing hormone-independent isosexual male precocity; PGRS, however, is considerably rarer than 11-BHD. Other than serum and urinary cortisol, which are elevated in PGRS and low/low-normal in 11-BHD, both of these conditions are indistinguishable by clinical, biochemical or radiological parameters. In 11-BHD, oxidation of 11-deoxycortisol (11-DOC) to cortisol is impaired, resulting in accumulation of 11-DOC and other cortisol precursors. 11-DOC shares structural homology with cortisol, and falsely elevated serum cortisol values are observed in older generation immunoassays (Siemens ADVIA Centaur) due to antibody cross-reactivity. 11-BHD, thus, may be misdiagnosed as PGRS. Structure-based cortisol assays are not widely available in low-income countries. Hence, immunoassays using highly specific antibodies against cortisol are required to ensure assay selectivity. Newer generation analysers probably are effective alternatives to liquid chromatography-tandem mass spectrometry in conditions associated with 11β-hydroxylase defect.


The Vitamin D External Quality Assessment Scheme (DEQAS) distributes serum samples globally, on a quarterly basis, to assess participants’ performance of specific methods for 25-hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (1,25-(OH)2D). DEQAS occasionally circulates samples containing high levels of substances found in certain clinical situations e.g. 25-OH-D2, 24,25-(OH)2D3, hypertriglyceridemia. The increased availability and use of health supplements containing biotin has led to case reports of assay interference in methods utilizing a biotin-streptavidin detection system. In October 2018, DEQAS included a serum sample (545) containing exogenous biotin (concentration =586 μg/L) which was analyzed by a total of 683 laboratories using 35 different methods. The same serum sample (544) without exogenous biotin was also included in the 5-sample set. All methods (760 laboratories) performed satisfactorily on sample 544 giving an All-Laboratory Trimmed Mean = 50.2 ± 6.5 nmol/L (±SD, CV = 12.9%). The target value for this sample 544 (& 555) was 47.4 nmol/L as determined by Centers for Disease Control and Prevention (CDC) Atlanta, Georgia using their LC-MS/MS reference method. In contrast, #545 containing the exogenous biotin was reported by only 683 laboratories and gave an All-Laboratory Trimmed Mean = 66.8 ± 37.6 nmol/L (±SD, CV = 56.3%). As expected, LC-MS/MS methods (143 labs) reported similar results for both 544 = 48.9 ± 4.4 nmol/L (±SD) and 545 = 48.3 ± 4.5 nmol/L (±SD) showing that assays involving chromatographic steps are unaffected by the presence of biotin. Several of the antibody-based assays including Abbott Architect, DiaSorin Liaison, Beckman Unicel and Siemens Centaur are also unaffected by the addition of biotin. Two assays, IDS-iSYS and Roche Total 25OHD, both of which use biotin-streptavidin, exhibit biotin interference yielding values with a significant positive bias for 545 of 102.6 nmol/L ± 78.7 nmol/L (±SD) and 517.8 nmol/L ± 209.8 nmol/L (±SD) respectively. Interestingly, the failure to report sample 545 data from 77 laboratories is due solely to those running Roche Total 25OHD or Roche Vitamin D Total II assays. Given the prevalence of the adversely affected assays (25% of DEQAS users) and the high volume of 25OHD testing, clinicians using these assays should, where possible, only measure 25OHD when patients are off biotin.

Performance of Novel High-Sensitivity Cardiac Troponin I Assays for 0/1-Hour and 0/2- to 3-Hour Evaluations for Acute Myocardial Infarction: Results From the HIGH-US Study.

We determine the accuracy of high-sensitivity cardiac troponin I (hs-cTnI), European-derived, rapid, acute myocardial infarction, rule-out/rule-in algorithms applied to a US emergency department (ED) population.Adults presenting to the ED with suspected acute myocardial infarction were included. Plasma samples collected at baseline and between 40 and 90 minutes and 2 and 3 hours later were analyzed in core laboratories using the Siemens Healthineers hs-cTnI assays. Acute myocardial infarction diagnosis was independently adjudicated. The sensitivity, specificity, and negative and positive predictive values for rapid acute myocardial infarction rule-out/rule-in using European algorithms and 30-day outcomes are reported.From 29 US medical centers, 2,113 subjects had complete data for the 0/1-hour algorithm analyses. With the Siemens Atellica Immunoassay hs-cTnI values, 1,065 patients (50.4%) were ruled out, with a negative predictive value of 99.7% and sensitivity of 98.7% (95% confidence interval 99.2% to 99.9% and 96.3% to 99.6%, respectively), whereas 265 patients (12.6%) were ruled in, having a positive predictive value of 69.4% and specificity of 95.7% (95% confidence interval 63.6% to 74.7% and 94.7% to 96.5%, respectively). The remaining 783 patients (37.1%) were classified as having continued evaluations, with an acute myocardial infarction incidence of 5.6% (95% confidence interval 4.2% to 7.5%). The overall 30-day risk of death or postdischarge acute myocardial infarction was very low in the ruled-out patients but was incrementally increased in the other groups (rule-out 0.2%; continued evaluations 2.1%; rule-in 4.8%). Equivalent results were observed in the 0/2- to 3-hour analyses and when both algorithms were applied to the hs-cTnI ADVIA Centaur measurements.The European rapid rule-out/rule-in acute myocardial infarction algorithm hs-cTnI cut points can be harmonized with a demographically and risk-factor diverse US ED population.

Patterns of HBeAg, HBsAg Clearance Among a Treatment-Naive Alaskan Cohort in a Long-Term Observational Study.

In this long-term observational study, we examined the patterns of HBsAg reduction in a cohort of patients with HBeAg (+) and (-) chronic hepatitis B (CHB) who achieved spontaneous HBsAg clearance CHB Patients were selected from an antiviral treatment-naive Alaska Native population who achieved HBsAg seroclearance from 1973 to 2009 with samples at least 2 years prior to HBsAg loss. ADVIA Centaur HBsAg and HBeAg quantitative assays (Siemens Healthcare Diagnostics, USA) were utilized. 17 HBeAg (+) and 48 HBeAg (-) patients with predominantly HBV genotypes D and F were enrolled. The average follow-up was 19.5 years and 16.4 years respectively. Rate of HBsAg clearance was significantly slower among the HBeAg (+) patients (p=0.001). HBsAg loss was more uniform at a rate of about 4% over 25 years for HBeAg (-) patients. Among the HBeAg (+) patients, the average decline in HBeAg (1.8 log IU/ml/year) and HBsAg (1.5 log IU/ml /year) from baseline to HBeAg loss were similar (p=0.2). The rate of HBsAg reduction was significantly faster before (1.5 log IU/ml/year) compared to after (0.4 log IU/ml /year) HBeAg clearance (p=0.004). The kinetic of HBsAg decline after HBeAg loss was similar to that among the HBeAg (-) patients (0.3 log IU/ml /year). The observation of a biphasic decline in HBsAg titers prior to and after HBeAg seroclearance is novel. HBsAg quantification over time provides valuable information on the natural course of CHB. Its kinetic can predict HBsAg loss especially in the HBeAg (-) phase of CHB.

Discrepancy between Cardiac Troponin Assays Due to Endogenous Antibodies.

Despite well-described analytical effects of autoantibodies against cardiac troponin (cTn) I on experimental assays, no study has systematically examined their impact on cTn assays in clinical use. We determined the effects of endogenous antibodies on 5 different cTnI assays and a cTnT assay.cTn was measured by 6 methods: Siemens hs-cTnI Centaur, Siemens hs-cTnI Vista, Abbott hs-cTnI Architect, Beckman hs-cTnI Access, Beckman cTnI Access, and Roche hs-cTnT Elecsys. Measurements were repeated on 5 assays (all except Siemens hs-cTnI Vista) following immunoglobulin depletion by incubation with protein A. Low recovery of cTnI (<40%) following immunoglobulin depletion was considered positive for macro-cTnI. Protein A findings were validated by gel filtration chromatography and polyethylene glycol precipitation.In a sample of 223 specimens selected from a community laboratory that uses the Siemens hs-cTnI Centaur assay and from which cTn was requested, 76% of samples demonstrated increased cTnI (median, 88 ng/L; interquartile range, 62-204 ng/L). Macro-cTnI was observed in 123 (55%) of the 223 specimens. Comparisons of cTnI assays markedly improved once patients with macro-cTnI were removed. Passing-Bablok regression analysis between hs-cTnI assays demonstrated different slopes for patients with and without macro-cTnI. In patients with macro-cTnI, 89 (72%) showed no effect on the recovery of cTnT, whereas 34 (28%) had reduced recovery of cTnT. The proportion of results above the manufacturers’ 99th percentile varied with the cTn assay and macro-cTnI status.We suggest that the observed discrepancy between hs-cTnI assays may be attributed in part to the presence of macro-cTnI.

Dataset of human platelets in healthy and individuals with cardiovascular pathology obtained by surface-enhanced Raman spectroscopy.

This data article contains Raman experimental data, obtained with Centaur U Raman spectrometer (Russia), which can be used for rapid and early structure changes and biomarkers identification in individuals with cardiovascular decease (CVD) pathology in vitro. The data include analyzed Surface-Enhanced Raman Scattering (SERS) spectra of human platelets taken from healthy individuals and individuals with cardiovascular pathology. Data can provide information about characteristic maxima of different cell components and its changes in platelets.

Cenicriviroc Treatment for Adults with Nonalcoholic Steatohepatitis and Fibrosis: Final Analysis of the Phase 2b CENTAUR Study.

Cenicriviroc (CVC) is a CCR2/5 dual antagonist under evaluation for treating liver fibrosis in adults with nonalcoholic steatohepatitis (NASH). Year 1 primary analysis of the 2-year CENTAUR study showed that CVC had an antifibrotic effect without impacting steatohepatitis. Herein, we report the final data from Year 2 exploratory analyses. This was a randomized, controlled study of adults with NASH, nonalcoholic fatty liver disease activity score ≥4, and NASH CRN stage 1-3 fibrosis. Participants in Arms A and C received CVC 150 mg or placebo, respectively, for 2 years; Arm B received placebo in Year 1 and switched to CVC in Year 2. Liver biopsy was performed at baseline, Year 1, and Year 2. Of 289 randomized, 242 participants entered Year 2. At Year 2, 24% of patients who switched to CVC and 17% who remained on placebo achieved ≥1-stage fibrosis improvement AND no worsening of NASH (P=0.37). Twice the proportion on CVC who achieved fibrosis response at Year 1 maintained benefit at Year 2 (60% Arm A vs. 30% Arm C), including 86% on CVC who had stage 3 fibrosis at baseline. Over 2 years, a similar proportion on CVC or placebo achieved ≥1-stage fibrosis improvement AND no worsening of NASH (15% Arm A vs. 17% Arm C). In patients with fibrosis responses, we observed consistent reductions in PRO-C3 levels and ELF scores, while increases in APRI and FIB-4 scores were consistently observed in non-responders. Safety profile was comparable across groups. Conclusions: CVC was well-tolerated, and Year 2 data corroborates antifibrotic findings from Year 1. Majority on CVC who achieved fibrosis response at Year 1 maintained it at Year 2, with greater effect in advanced fibrosis.

Repeated false reactive ADVIA centaur® and bio-rad Geenius™ HIV tests in a patient self-administering anabolic steroids.

An individual is considered HIV positive when a confirmatory HIV-1/HIV-2 differentiation test returns positive following an initial reactive antigen/antibody combination screen. Falsely reactive HIV screens have been reported in patients with various concomitant infectious and autoimmune conditions. Falsely positive confirmatory HIV differentiation assays are seen less frequently, but have been observed in cases of pregnancy, pulmonary embolism, and malaria.A healthy 27 year-old man was referred after a reactive ADVIA Centaur® HIV Ag/Ab screen and positive Bio-Rad Geenius™ HIV 1/2 Confirmatory assay, suggesting HIV-1 infection. The patient’s HIV viral load was undetectable prior to initiation of antiretroviral therapy, and remained undetectable on subsequent testing after initiation of antiretroviral therapy. Both Centaur® and Geenius™ tests were repeated and returned reactive. As this patient was believed to be at low risk of acquiring HIV infection, samples were additionally run on Genscreen™ HIV-1 Ag assay and Fujirebio Inno-LIA™ HIV-1/2 score, with both returning non-reactive. For confirmation, the patient’s proviral HIV DNA testing was negative, confirming the initial results as being falsely positive. The patient disclosed that he had been using a variety of anabolic steroids before and during the time of HIV testing.The erroneous diagnosis of HIV can result in decreased quality of life and adverse effects of antiretroviral therapy if initiated, hence the importance of interpreting the results of HIV testing in the context of an individual patient. This reports suggests a potential association between the use of anabolic steroids and falsely-reactive HIV testing.

Validation of the ADVIA Centaur® XP system for the determination of insulin and its application.

In this study, a direct chemiluminescent immunoassay for the determination of human serum insulin levels using the ADVIA Centaur® XP system was validated. Dilution recovery, linearity, precision, sensitivity, between analyzer variation, reference interval and stability were analyzed. The linear range of the insulin assay was from 0.64 to 277.27 mU/L. Intra- and inter-assay coefficients of variation were 3.67-7.96% and 4.66-8.69%, respectively. The lower and upper limits of quantification were 0.61 mU/L and 8872.64 mU/L, respectively. In terms of between analyzer variation, our study showed comparable results with a good correlation of r2 = 0.9934. The human serum insulin reference interval was in the range of 3.0-25.0 mU/L. Serum insulin can be kept for 7 days between 2-8 °C and 18-26 °C, and the corresponding results for -20 °C and -70 °C were 1 month and 6 months are reported. We proved that this insulin assay was robust and the analytical performance met the requirements. We successfully applied this insulin assay to a bioequivalence study of miglitol in 48 healthy Chinese subjects. The miglitol bioequivalence study was evaluated based on pharmacokinetic and pharmacodynamic parameter endpoints. The results demonstrated that the test formulation and the reference formulation were bioequivalent.

Thyroid function abnormalities and thyroid autoantibodies in Danish pregnant women.

Abnormal thyroid function in pregnant women is a matter of concern. Knowledge on the occurrence of known and unidentified thyroid function abnormalities in a large unselected cohort of pregnant women is warranted as part of the debate on benefits and risks of routine testing.Cohort study PARTICIPANTS: 14,323 pregnant women in the North Denmark Region, who had a blood sample drawn as part of the prenatal screening program in early pregnancy (2011-2015).TSH, free thyroxine, thyroid peroxidase and thyroglobulin antibodies were measured in the stored blood samples using an automatic immunoassay (ADVIA Centaur XPT, Siemens Healthineers). Cohort-, method-, and week-specific reference ranges were used for classification of maternal thyroid function and a cut-off of 60 U/ml was used for thyroid autoantibodies. Information in Danish nationwide registers was used to identify diagnosed and treated maternal thyroid disease.Overall, 15.2% had thyroid function abnormalities in the early pregnancy and 14.9% were thyroid peroxidase and/or thyroglobulin antibody positive. Among women with known thyroid disease (n=365), the frequency of abnormal thyroid function was 45.7%, and 62.8% in women (n=172) who received current treatment in the pregnancy. When maternal thyroid disease was diagnosed in the years following pregnancy (n=313), 46.7% had abnormal thyroid function and 54.3% were thyroid peroxidase and/or thyroglobulin antibody positive in the early pregnancy.Thyroid function abnormalities and thyroid autoantibodies were common in Danish pregnant women, particularly in women with known or later diagnosed thyroid disease, which raises concern about inadequately treated and unidentified abnormal thyroid function.

Thyroid stimulating hormone values of clinical decisions of hypothyroidism measurement by three different automated immunoassays.

Background: An accurate measurement of serum thyroid stimulating hormone (TSH) is crucial for a thyroid disorder diagnosis and management. We compared the values of TSH between three automated immunoassays with aims to provide insights into variations in TSH levels that are important for a clinical decision: 2.50 mIU/L, 4.00 mIU/L and 10.00 mIU/L.Methods: We measured TSH with three different fully automated immunoassays: Abbott (Architect ci8200), Siemens (ADVIA Centaur XP) and Roche (Cobas e411). Serum was collected from 110 patients between August 2018 and January 2019. The results were compared using the Passing-Bablok regression method. Additionally, linear regression coefficients were calculated after logarithmic transformation of data.Results: Although all three regression coefficients were high (r2 > 0.98), the slopes from Passing-Bablok plots for the correlation of Abbott with either Roche or Siemens were merely 0.66 and 0.73, respectively. The slope for the correlation of Roche and Siemens was 1.11. Consecutively, the results obtained by the Roche and Siemens methods were proportionally higher than those obtained by the Abbott method (38% and 52%, respectively) at all measured ranges.Conclusions: Although immunoassays correlated among themselves, they cannot achieve the same values for clinical decisions for hypothyroidism (clinical requirements). Clinicians should be conscious of these limitations. A harmonisation of the methods is needed to meet clinical requirements and to enable appropriate clinical decisions in cases of hypothyroidism.Likewise, we suggest the introduction of borderline and high risk values of TSH for hypothyroidism depending on immunoassays to avoid misdiagnosis.

Routine free thyroxine reference intervals are suboptimal for monitoring children on thyroxine replacement therapy and target intervals need to be assay-specific.

Central hypothyroidism is a condition where there is (qualitatively or quantitatively) TSH deficiency, leading to reduced thyroid hormone production. In such patients, serum TSH does not accurately reflect the adequacy of thyroxine replacement, as the log-linear relationship between thyrotropin (TSH) and free thyroxine (FT4) is lost. We aimed to prospectively determine the optimal physiological FT4 treatment range for children treated for primary hypothyroidism, based on their serum TSH concentrations. This information could be used to guide optimal therapy for all children on thyroxine replacement, including those with central hypothyroidism. In total, sixty children (median age: 11 years, range: 11 months to 18 years) were recruited over 21 months. They were prescribed a stable dose of thyroxine for at least 6-8 weeks prior to a thyroid function test that consisted of serum TSH, FT4 and free triiodothyronine (FT3) measurements. The serum sample for the thyroid function tests was collected before ingestion of the daily dose, i.e. the trough concentration, and measured using Beckman Coulter UniCel DxI 800 instrument, Siemens Advia Centaur, Roche Cobas, Abbott Architect, Ortho Clinical Diagnostics Vitros 5600 (Ortho-Clinical Diagnostics, Raritan, NJ) platforms. The FT4 and FT3 reference intervals showed significant inter-method difference. The lower limit of the FT4 reference intervals were generally shifted mildly higher when the TSH concentration of the children were restricted from 0.5-5.0 mIU/L to 0.5-2.5 mIU/L. By contrast, the upper limit of the FT3 and FT4 reference intervals were relatively stable for the different TSH concentrations. Assay-specific target ranges for optimal thyroxine therapy are required until FT4 assay standardisation is realised.

Monitoring of omalizumab therapy in children and adolescents.

Omalizumab is a successfully implemented supplementary therapy for improving asthma control in children aged 6 years and older with severe persistent allergic asthma. The dosage of omalizumab depends on body weight and IgE level, yet no parameter has been established to guide dosage changes during therapy. Clinical studies in patients with allergic asthma or allergic rhinitis revealed a clinically relevant improvement by using omalizumab leading to concentrations of free serum IgE reported to be lower than 50 ng/ml. Therefore, only the question concerning the concentrations of free IgE used in a therapy with omalizumab is regarded of clinical importance, while total IgE (free and omalizumab-bound IgE) increases during treatment.Ten patients, 8 to 17 years of age, received therapy with omalizumab due to severe allergic asthma. In addition, the patients had pronounced rhinoconjunctivitis, food allergy, insect sting allergy, and/or neurodermitis. The total IgE in the serum was measured in the patients 3 – 6 months before each omalizumab injection as a potential progress parameter (Sandwich-Immunoassay ADVIA Centaur).Six months after beginning of the therapy with omalizumab, a significant decrease of the total IgE concentration was found, in comparison to the baseline values (p < 0.003). In all patients the tolerability of omalizumab was very good: there was a reduction in the frequency of the asthma exacerbations and rescue medications. All patients reported a clearly improved quality of life.A general increase in IgE was not observed in any of the children we treated with omalizumab. Apart from the development of routine assays to determine free serum IgE levels, the significance of the total serum IgE as a suitable control of an omalizumab therapy should be further investigated in controlled studies with regard to sensitivity and specificity. In order to only administer the lowest necessary dose of omalizumab especially in children and adolescents, the establishment of laboratory parameters (free IgE and/or total IgE) to adequately monitor the therapy is urgently needed. Patients undergoing an omalizumab therapy require medical supervision at close intervals.

Comparison of four decision aids for the early diagnosis of acute coronary syndromes in the emergency department.

To directly compare the diagnostic accuracy of four decision aids (Troponin-only Manchester Acute Coronary Syndromes (T-MACS), History, ECG, Age, Risk factors and Troponin (HEART), Thrombolysis in Myocardial Infarction (TIMI) and Emergency Department Assessment of Chest Pain (EDACS)) used to expedite the early diagnosis of acute coronary syndromes (ACS) in the ED.We prospectively included patients who presented to 14 EDs in England (February 2015 to June 2017) with suspected ACS within 12 hours of symptom onset. Data to enable evaluation of the T-MACS, HEART, TIMI and EDACS decision aids (without recalibration) were prospectively collected, blinded to patient outcome. We tested admission blood samples for high-sensitivity cardiac troponin I (hs-cTnI; Siemens ADVIA Centaur). Patients also underwent serial cardiac troponin testing over 3-12 hours. The target condition was an adjudicated diagnosis of acute myocardial infarction (AMI). We also evaluated the incidence of major adverse cardiac events (including death, AMI or coronary revascularisation) at 30 days. Diagnostic accuracy of each decision aid and hs-cTnI alone (using the limit of quantification cut-off, 3 ng/L) was evaluated by calculating sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).Of 999 included patients, 132 (13.2%) had AMI. C-statistics were 0.96 for T-MACS, 0.78 for HEART and 0.69 for TIMI. The sensitivities of T-MACS, HEART, TIMI, EDACS and hs-cTnI <3 ng/L for AMI were 99.2% (95% CI 95.7% to 100.0%), 91.8% (85.0% to 96.2%), 97.5% (92.9% to 99.5%), 96.2% (92.2% to 99.4%) and 99.2% (95.9% to 100.0%), respectively. The respective strategies would have ruled out 46.5%, 34.9%, 19.4%, 48.3% and 28.8% patients. PPVs for the decision aids that identify ‘high-risk’ patients were 80.4% (T-MACS), 51.9% (TIMI) and 37.2% (HEART).In this study, T-MACS could rule out AMI in 46.5% patients with 99.2% sensitivity. EDACS could rule out AMI in 48.3% patients with lower sensitivity, although the difference was not statistically significant. The HEART and TIMI scores had lower diagnostic accuracy.

Serum Level of Biotin Rather than the Daily Dosage Is the Main Determinant of Interference on Thyroid Function Assays.

Several case reports stress that high-dose biotin causes incorrect laboratory results. However, the extent of this interference in children is not systematically studied.To assess factors associated with biotin interference on thyroid function tests in subjects with biotinidase deficiency.The study included 44 children who were treated with oral biotin (Group 1, median dose: 10 mg/day [25-75p; 10-10], age: 1.83 years [1.04-2.90]) and 30 healthy subjects (Group 2, age: 1.05 years [0.37-3.37]). Thyroid function tests were performed with two different assays, and streptavidin-coated particles were used in order to remove biotin from serum samples of cases with biotin interference.The measurements were first performed with Beckman Coulter. In Group 1, remarkably high levels of fT3 and fT4 were found in 26 (59.1%) and 25 (56.8%) patients, respectively. Thyroid hormone functions were all normal in Group 2. Significantly higher serum biotin levels were detected in interference-positive children (p < 0.001). The serum biotin levels in Group 1 showed a strong positive correlation with fT3 (r = 0.867, p < 0.001) and fT4 levels (r = 0.905, p < 0.001). A serum biotin level of 80.35 µg/L was found to be the best cut-off value for predicting interference (sensitivity: 96.2% and specificity: 94.4%). When analyzed with Siemens Advia Centaur XP, all thyroid function tests were normal in both groups except in one patient (2.27%) with slightly elevated fT3 level in Group 1. Repeated tests with Beckman Coulter after neutralization of biotin with streptavidin magnetic particles in serum samples of the interference-positive cases revealed normal thyroid hormone levels.Interference is an important problem in thyroid function tests in nearly 60% of all children receiving biotin treatment for biotinidase deficiency. Serum levels of biotin rather than the dosage are the main determinant of interference, which can be eliminated by choosing appropriate laboratory methods.

Multi-site performance evaluation and Sigma metrics of 20 assays on the Atellica chemistry and immunoassay analyzers.

Background The Atellica Solution comprises chemistry (CH) and immunoassay (IM) analyzers. Recently, six early adopter clinical laboratories across Europe evaluated the analytical performance of 20 CH and IM assays. To measure analytical performance quality, Sigma metrics were calculated for individual-site and pooled-site results. Methods Precision, detection capability, linearity, and method comparison studies were performed according to Clinical Laboratory Standards Institute protocols. Global Sigma metrics across sites were calculated from pooled data at the medical decision level using total allowable error (TEa) goals from CLIA for CH assays, and TEa goals from RiliBÄK for IM assays; and, the equation: Sigma metrics=%TEa-%bias/%CV. A pooled %CV was calculated by combining the imprecision obtained from individual sites. Bias calculations were performed against the ADVIA Chemistry system or ADVIA Centaur system using Deming regression analysis (Passing-Bablok regression for electrolytes) on the pooled-site data. The 103 individual-site Sigma metric calculations used individual-site imprecision and pooled-bias. Results The limits of blank and detection results agreed with the manufacturer’s claims. Most assays were linear across the assay range tested. Pooled Sigma metrics were good or better (>4 Sigma) for 18 of 20 assays; and, acceptable for urea nitrogen (3.1) and sodium (3.9), the latter values attributable to higher imprecision at one of five sites. Conclusions Sigma metrics for data generated across multiple real-world sites evaluating the Atellica Solution demonstrated good or better performance of greater than 4 Sigma for 18 of 20 assays tested. Overall, results verified the manufacturer’s claims that methods were fit for use in clinical laboratories.

Evaluation of the Bio-Rad BioPlex 2200 Toxoplasma gondii IgM Multiplex Flow Immunoassay.

Toxoplasmosis is routinely diagnosed through detection of Toxoplasma gondii-specific antibodies. However, the imperfect specificity of T. gondii serologic assays is a well-recognized limitation. The new BioPlex 2200 (Bio-Rad Laboratories) T. gondii, rubella, and cytomegalovirus (ToRC) IgM multiplex flow immunoassay (MFI) received FDA clearance in May 2017. We evaluated the clinical performance of the new T. gondii IgM and existing IgG portion of this MFI.
Three hundred prospectively collected consecutive, residual sera, submitted for T. gondii serologic testing as part of routine clinical care, and an archived set of 52 residual sera previously positive for anti-T. gondii IgM and IgG with the predicate ADVIA Centaur Toxoplasma IgM and IgG assays (Siemens) were evaluated. Performance of the BioPlex 2200 T. gondii IgM and IgG MFIs was assessed by calculating positive (PPA) and negative percent agreement (NPA) compared to the Centaur tests.
Among prospective specimens, the BioPlex 2200 T. gondii IgM and IgG MFIs demonstrated a PPA of 0% (0/7) and 82.3% (28/34) and NPA of 99.3% (288/290) and 95.8% (251/262), respectively, with the Centaur assays. Chart review of the 7 Centaur T. gondii IgM-positive samples revealed that these were likely falsely positive. Among archived samples, the BioPlex 2200 T. gondii IgM and IgG MFIs showed PPAs of 90.4% (47/52) and 100% (52/52), respectively.
The BioPlex 2200 T. gondii IgM and IgG MFIs demonstrated excellent concordance with the Centaur assays. The T. gondii IgM MFI may provide higher specificity in low-prevalence populations.

Apparent resistance to thyroid hormones: From biological interference to genetics.

Resistance to thyroid hormones syndrome is defined as increased thyroxine (T4) and triiodothyronine (T3) concentrations associated with normal or sometimes increased thyrotropin (TSH) concentration. This is usually due to a pathogenic variant with loss of function of the gene coding for thyroid hormone receptor β (THRB). This discrepancy in thyroid hormones (TH) and TSH concentrations is also frequently observed in the presence of analytical interference, notably alteration of TH transport proteins in serum. During 2017, 58 samples were sent to our laboratory in the Angers University Hospital Rare Thyroid and Hormone Receptor Disease Reference Center in order to identify an etiology for discrepant TSH and TH results. We sequenced the genes involved in TH regulation, action and transport (THRB,THRA, SECISBP2, SLC16A, ALB, TTR, SERPINA7). Free T4 and free T3 assay were performed with a second immunoassay (Siemens ADVIA Centaur). A genetic cause of discrepancy in TH and TSH concentrations, with mutation in THRB, was found in 26% of cases (15/58). Biological interference due to TH serum transport protein variant was found in 24% (14/58) of cases. No pathogenic variants were found in the other genes studied. Biological interference was also suspected in 26% of cases without genetic variant, in which the biological discrepancy was not confirmed by a second analytical technique (15/58). Finally, no etiology for the biological discrepancy could be found in 24% of cases (14/58). Clinically, patients in whom biological discrepancy was due to analytic interference were more often asymptomatic, and patients with no identified etiology tended to be older. To limit diagnostic errors associated with the finding of discrepant TSH and TH, we recommend initially conducting a second thyroid function test (TSH, free T4 and free T3) with a different assay, and then screening for a genetic variant in gene coding for thyroid hormone receptor β (THRB) and the TH serum transport proteins (ALB, TTR, SERPINA7).

Clinical Use of a New High-Sensitivity Cardiac Troponin I Assay in Patients with Suspected Myocardial Infarction.

We aimed to validate the clinical performance of the high-sensitivity cardiac troponin I [VITROS® Immunodiagnostic Products hs Troponin I (hs-cTnI-VITROS)] assay.We enrolled patients presenting to the emergency department with symptoms suggestive of acute myocardial infarction (AMI). Final diagnoses were centrally adjudicated by 2 independent cardiologists considering all clinical information, including cardiac imaging: first, using serial hs-cTnT-Elecsys (primary analysis) and, second, using hs-cTnI-Architect (secondary analysis) measurements in addition to the clinically used (hs)-cTn. hs-cTnI-VITROS was measured at presentation and at 1 h in a blinded fashion. The primary objective was direct comparison of diagnostic accuracy as quantified by the area under the ROC curve (AUC) of hs-cTnI-VITROS vs hs-cTnT-Elecsys and hs-cTnI-Architect, and in a subgroup also hs-cTnI-Centaur and hs-cTnI-Access. Secondary objectives included the derivation and validation of an hs-cTnI-VITROS-0/1-h algorithm.AMI was the adjudicated final diagnosis in 158 of 1231 (13%) patients. At presentation, the AUC for hs-cTnI-VITROS was 0.95 (95% CI, 0.93-0.96); for hs-cTnT-Elecsys, 0.94 (95% CI, 0.92-0.95); and for hs-cTnI-Architect, 0.92 (95% CI, 0.90-0.94). AUCs for hs-cTnI-Centaur and hs-cTnI-Access were 0.95 (95% CI, 0.94-0.97). Applying the derived hs-cTnI-VITROS-0/1-h algorithm (derivation cohort n = 519) to the validation cohort (n = 520), 53% of patients were ruled out [sensitivity, 100% (95% CI, 94.1-100)] and 14% of patients were ruled in [specificity, 95.6% (95% CI, 93.4-97.2)]. Patients ruled out by the 0/1-h algorithm had a survival rate of 99.8% at 30 days. Findings were confirmed in the secondary analyses using the adjudication including serial measurements of hs-cTnI-Architect.The hs-cTnI-VITROS assay has at least comparable diagnostic accuracy with the currently best validated hs-cTnT and hs-cTnI assays.

Detection and characterization of estradiol (E2) and unconjugated estriol (uE3) immunoassay interference due to anti-bovine alkaline phosphatase (ALP) antibodies.

Competitive immunoenyzmatic assays for estradiol (E2) and unconjugated estriol (uE3) on UniCel DxI 800 Access immunoassay systems (Beckman Coulter) utilize bovine alkaline phosphatase (ALP) for amplification. In these assays, rare ‘IND’ error flags indicate that a relative light unit (RLU) raw result is past the high or low end of the calibration curve but cannot be differentiated from an instrument error or analytical interference. The present studies were conducted to establish a protocol to identify analytical interference and to characterize its mechanism when present.
Design and methods
Matrix and recovery studies were conducted to establish a protocol for interference identification. Spiking experiments with inactivated calf intestinal ALP were performed to determine whether interference could be blocked. Commercial anti-ALP antibodies (Abs) were spiked into human serum to model assay interference. Three E2 immunoassays which do not include ALP as a reagent component (cobas e602, Roche; Centaur XP, Siemens; ARCHITECT i2000SR, Abbott) were tested for comparative purposes.
1:2 dilution of specimen into Access Sample Diluent A (Beckman) differentiated IND error flags due to true low results (e.g. less than the analytical measurement range; AMR) from those due to assay interference. Interferences were reduced by pre-incubation with inactivated ALP and could be replicated by spiking with commercial anti-ALP Abs.Patient anti-bovine ALP Abs can cause interference on DxI 800 E2 and uE3 assays. This model can be used to investigate interference risk with other ALP-dependent assays.

Do Prophylactic Antibiotics Reach the Operative Site Adequately?: A Quantitative Analysis of Serum and Wound Concentrations of Systemic and Local Prophylactic Antibiotics in Spine Surgery.

Prospective Cohort Study OBJECTIVE.: To analyse the serum and drain concentrations of antibiotics administered by two different routes and compare the results.Systemic antibiotics are expected to reach the surgical site and maintain adequate concentrations of the drug to prevent infection. However, It is unknown whether systemically administered antibiotics reach and maintain such adequate concentrations at the surgical wound or not.40 patients undergoing elective spine surgery received intra wound Vancomycin (1 GM) before the wound closure and single dose of intravenous Gentamycin (80MG) immediately after surgery. Blood and Drain samples were collected post-operatively to estimate serum and drain concentrations of Gentamycin and Vancomycin.Drug Estimation Protocol: Drug concentrations were estimated by ADVIA Centaur CP immunoassay (direct chemiluminescence). Gentamycin and vancomycin in the test samples competes with their respective acridinium ester-labelled gentamicin and vancomycin derivatives for monoclonal mouse anti-gentamycin and anti-vancomycin antibodies which are covalently coupled to paramagnetic particles in the Solid Phase.Gentamycin attained peak serum levels at 6 hours following administration with an average value of 9.90 ± 3.1 μg/mL which was decreased to 6.76 ± 2.6 μg/mL at 12 hours and steadily declining thereafter. Even though, the drug concentrations in the drain collection from the wound also attained peak levels at 6 hours, the drug concentrations were lower (3.75 ± 1.4 μg/mL) than that of serum concentrations and inadequately attained the recommended target peak of Gentamycin (4-12 μg/mL).Wound levels of local vancomycin was significantly higher at 6 hours (413.4 ± 217.3 μg/mL) and well maintained even at 72 hours. Serum vancomycin levels were observed to be highest at 6 hours in negligible concentrations of 6.06 ± 2.2 μg/mL.After prophylactic systemic administration of the antibiotics, the antibiotic drug concentrations in the wound are much lower than the serum concentrations at any given time. After local intra wound application of antibiotics, the drug concentrations in the wound are well maintained even after 72 hours.Level of evidence- 3.

A comprehensive validation of very early rule-out strategies for non-ST-segment elevation myocardial infarction in emergency departments: protocol for a multicentre prospective cohort study.

Recent advances in troponin sensitivity enabled early and accurate judgement of ruling-out myocardial infarction, especially non-ST elevation myocardial infarction (NSTEMI) in emergency departments (EDs) with development of various prediction-rules and high-sensitive-troponin-based strategies (hs-troponin). Reliance on clinical impression, however, is still common, and it remains unknown which of these strategies is superior. Therefore, our objective in this prospective cohort study is to comprehensively validate the diagnostic accuracy of clinical impression-based strategies, prediction-rules and hs-troponin-based strategies for ruling-out NSTEMIs.In total, 1500 consecutive adult patients with symptoms suggestive of acute coronary syndrome will be prospectively recruited from five EDs in two tertiary-level, two secondary-level community hospitals and one university hospital in Japan. The study has begun in July 2018, and recruitment period will be about 1 year. A board-certified emergency physician will complete standardised case report forms, and independently perform a clinical impression-based risk estimation of NSTEMI. Index strategies to be compared will include the clinical impression-based strategy; prediction rules and hs-troponin-based strategies for the following types of troponin (Roche Elecsys hs-troponin T; Abbott ARCHITECT hs-troponin I; Siemens ADVIA Centaur hs-troponin I; Siemens ADVIA Centaur sensitive-troponin I). The reference standard will be the composite of type 1 MI and cardiac death within 30 days after admission to the ED. Outcome measures will be negative predictive value, sensitivity and effectiveness, defined as the proportion of patients categorised as low risk for NSTEMI. We will also evaluate inter-rater reliability of the clinical impression-based risk estimation.The study is approved by the Ethics Committees of the Kyoto University Graduate School and Faculty of Medicine and of the five hospitals where we will recruit patients. We will disseminate the study results through conference presentations and peer-reviewed journals.

Analytical performance evaluation and enhancement of the ADVIA Centaur® HIV Ag/Ab Combo assay.

Fourth-generation immunoassays (such as the ADVIA Centaur® HIV Ag/Ab Combo (CHIV) assay) have improved the early diagnosis of human immunodeficiency virus (HIV), and their sensitivity and specificity usually exceed 99%. In regions with a low prevalence of HIV infection, however, the regular occurrence of false positives interferes with a medical laboratory’s workflow. The additional reagent and staff costs associated with false positives can nevertheless be avoided or reduced by gaining a better knowledge of the CHIV assay’s performance.To improve our HIV diagnosis strategy, we retrospectively analyzed all the Centaur® CHIV assays and confirmatory tests performed at Amiens University Medical Center between 2012 and 2018. We used open-source machine learning software to process this large database, develop a predictive model, and identify a new cut-off for Centaur® CHIV index interpretation.A total of 56,682 HIV serological assay results were analyzed. The results of the CHIV assay were initially reactive or indeterminate for 449 samples. After p24 antigen and/or immunoblotting, there were 171 (38%) false positives and 278 (62%) confirmed true positives. The application of a cut-off of 2.12 led to reclassification of 130 of the 171 false positives as true negatives. Combining our predictive model with medical record analysis reduced the number of false positive CHIV assay results from 171 to 12.The efficiency of the Centaur® CHIV assay can be increased by adjusting its cut-off for positivity. This adjustment may reduce the number of unnecessary confirmatory tests and accelerate the delivery of HIV test results.


Most known trans-Neptunian objects (TNOs) gravitationally scattering off the giant planets have orbital inclinations consistent with an origin from the classical Kuiper belt, but a small fraction of these “scattering TNOs” have inclinations that are far too large (i > 45°) for this origin. These scattering outliers have previously been proposed to be interlopers from the Oort cloud or evidence of an undiscovered planet. Here we test these hypotheses using N-body simulations and the 69 centaurs and scattering TNOs detected in the Outer Solar Systems Origins Survey and its predecessors. We confirm that observed scattering objects cannot solely originate from the classical Kuiper belt, and we show that both the Oort cloud and a distant planet generate observable highly inclined scatterers. Although the number of highly inclined scatterers from the Oort Cloud is ~3 times less than observed, Oort cloud enrichment from the Sun’s galactic migration or birth cluster could resolve this. Meanwhile, a distant, low-eccentricity 5 M⊕ planet replicates the observed fraction of highly inclined scatterers, but the overall inclination distribution is more excited than observed. Furthermore, the distant planet generates a longitudinal asymmetry among detached TNOs that is less extreme than often presumed, and its direction reverses across the perihelion range spanned by known TNOs. More complete models that explore the dynamical origins of the planet are necessary to further study these features. With observational biases well-characterized, our work shows that the orbital distribution of detected scattering bodies is a powerful constraint on the unobserved distant solar system.

Heterophile antibody interference affecting multiple Roche immunoassays: A case study.

Analysis of many clinically important analytes is dependent on antibody-based assays. However, depending on the design, these assays are vulnerable to interference from endogenous molecules including circulating antibodies and free biotin. In this case report, we describe a patient whose laboratory findings from immunoassay based methodologies, are inconsistent with the clinical presentation.A 14-year-old male was referred to Pediatric Endocrinology for suspected hyperthyroidism based on critically elevated free thyroxine (fT4) levels although clinical assessment was inconsistent with hyperthyroidism. Because repeat testing was discrepant, Endocrinology questioned the validity of the results prompting consultation with the laboratory to investigate the source of the inconsistent findings. Review of discordant results revealed that fT4 levels measured in laboratories utilizing Roche instrumentation were critically high, while results from laboratories using alternative platforms (i.e. Siemens Centaur) were within normal limits.After a comprehensive evaluation which included testing of paired specimens on multiple platforms, measurement of serially diluted specimens and a formal evaluation for the presence of heterophile antibodies, it was determined that a heterophile antibody interference was the most likely cause of the aberrant results in this patient.

Myocardial Infarction Risk Stratification With a Single Measurement of High-Sensitivity Troponin I.

Limited data exist on rapid risk-stratification strategies using the U.S. Food and Drug Administration-cleared high-sensitivity cardiac troponin I (hs-cTnI) assays.This study sought to examine single measurement hs-cTnI to identify patients at low and high risk for acute myocardial infarction (MI).This was a prospective, multicenter, observational study of patients with suspected acute MI enrolled across 29 U.S. sites with hs-cTnI measured using the Atellica IM TnIH and ADVIA Centaur TNIH (Siemens Healthineers) assays. To identify low-risk patients, sensitivities and negative predictive values (NPVs) for acute MI and MI or death at 30 days were examined across baseline hs-cTnI concentrations. To identify high-risk patients, positive predictive values and specificities for acute MI were evaluated.Among 2,212 patients, acute MI occurred in 12%. The limits of detection or quantitation resulted in excellent sensitivities (range 98.6% to 99.6%) and NPVs (range 99.5% to 99.8%) for acute MI or death at 30 days across both assays. An optimized threshold of <5 ng/l identified almost one-half of all patients as low risk, with sensitivities of 98.6% (95% confidence interval: 97.2% to 100%) and NPVs of 99.6% (95% confidence interval: 99.2% to 99.9%) for acute MI or death at 30 days across both assays. For high-risk patients, hs-cTnI ≥120 ng/l resulted in positive predictive values for acute MI of ≥70%.Recognizing the continuous relationship between baseline hs-cTnI and risk for adverse events, using 2 Food and Drug Administration-cleared hs-cTnI assays, an optimized threshold of <5 ng/l safely identified almost one-half of all patients as low risk at presentation, with hs-cTnI ≥120 ng/l identifying high-risk patients.
Head-to-head comparison of plasma cTnI concentration values measured with three high-sensitivity methods in a large Italian population of healthy volunteers and patients admitted to emergency department with acute coronary syndrome: A multi-center study.

The study aim is to compare cTnI values measured with three high-sensitivity (hs) methods in apparently healthy volunteers and patients admitted to emergency department (ED) with acute coronary syndrome enrolled in a large multicentre study.Heparinized plasma samples were collected from 1511 apparently healthy subjects from 8 Italian clinical institutions (mean age: 51.5 years, SD: 14.1 years, range: 18-65 years, F/M ratio:0.95). All volunteers denied chronic or acute diseases and had normal values of routine laboratory tests. Moreover, 1322 heparinized plasma sample were also collected by 9 Italian clinical institutions from patients admitted to ED with clinical symptoms typical of acute coronary syndrome. The reference study laboratory assayed all plasma samples with three hs-methods: Architect hs-cTnI, Access hs-cTnI and ADVIA Centaur XPT methods. Principal Component Analysis (PCA) was also used to analyze the between-method differences among hs-cTnI assays.On average, a between-method difference of 31.2% CV was found among the results of hs-cTnI immunoassays. ADVIA Centaur XPT method measured higher cTnI values than Architect and Access methods. Moreover, 99th percentile URL values depended not only on age and sex of reference population, but also on the statistical approach used for calculation (robust non-parametric vs bootstrap).Due to differences in concentrations and reference values, clinicians should be advised that plasma samples of the same patient should be measured for cTnI assay in the same laboratory. Specific clinical studies are needed to establish the most appropriate statistical approach to calculate the 99th percentile URL values for hs-cTnI methods.

How Do Contrast Agents Affect Cardiac Markers and Coagulation Tests? Experimental Study.

The discovery that biotin interferes with results of troponin and Nt-proBNP led some commercial firms to update their measurement methods. In particular, the clinical incompatibility of cardiac test results may affect the risk of morbidity and mortality.The aim of this study is to investigate the interference effects of 7 different contrast agents on cardiac markers (Troponin-I, Nt-proBNP, Mass CK-MB, CK, AST, LDH) and in coagulation tests (PT, APTT).Seven different contrast media were added into control materials by using interference protocol. The concentrations of PT, APTT, CK, AST, LDH, Mass CK-MB, Troponin-I, and Nt-proBNP were measured by Sysmex CS-2100, Abbott c16000, Siemens Centaur XP and AFİAS-6 analyzer. The number of deviations from target values was calculated.The 7 different contrast media caused negative interference in troponin levels between 57.43% and 62.87%. It was found that different contrast media produced false negativity in the Nt-proBNP test, ranging from 6.11% to 96.01%. Enzymes and coagulation tests were less affected.Different contrast media may cause false negatives in cTnI and Nt-proBNP. The contrast medium that causes the least interference should be preferred. The results of samples taken in the first hour after contrast imaging should be interpreted with care.

Performance Evaluation of Cardiac Troponin I Assay: A Comparison Between the Point-of-care Testing Radiometer AQT90 FLEX and the Central Laboratory Siemens Advia Centaur Analyzer.

Background To validate the point of care testing (POCT) Trop-I analyzer and compare it with a central laboratory-based chemiluminescence immunoassay, in order to evaluate its performance for use in critical care areas. Moreover, for clinical decision-making, it is imperative to know the extent to which patient stratification will differ based on the analytic method being used. In particular, the aim of this study was to evaluate the analytical performance of the point-of-care analyzer and demonstrate the agreement with the central laboratory measurements in patients presenting to the emergency department (ED) with chest pain and suspected acute coronary syndrome (ACS). Methods This cross-sectional study was performed at the section of chemical pathology, department of pathology and laboratory medicine, the Aga Khan University (AKU), Karachi, from October to November 2017. Samples from patients and the quality control material of Trop-I were analyzed for imprecision, linearity, and method comparison on Advia Centaur (Siemens Diagnostics, CA, USA), and the AQT90 FLEX analyzer (Radiometer Medical ApS, Brønshøj, Denmark) with photometric detection at the section of chemical pathology, AKU. Statistical analysis was done using Microsoft Excel (Microsoft Corporation, Washington, United States) and EP Evaluator version (Data Innovations, LLC, VT, US). Quantitative variables were represented in terms of mean ± SD. For precision, the computed SD was compared with allowable random error. Furthermore, Cohen’s kappa was applied to observe the agreement between the two methods. Results The Trop-I Precision study on the POCT analyzer showed a coefficient of variation (CV) of 2.4% using a pooled patient sample with a mean Trop-I of 2.15 ± 0.05 ng/ml. Three standards ranging from 0.034 to 1.316 ng/ml were run in triplicate to verify accuracy and linearity. The allowable systematic error (SEa) was 10.0%. The maximum deviation for a mean recovery from 100% was 4.1%. All three of the mean recoveries were accurate and within the allowable error limits. The results were linear with slope 1.04, intercept 0.0. On a method comparison, Trop-I showed good agreement, yielding a kappa value of 0.95. Conclusion This study has validated the performance of a POCT Trop-I assay against a central laboratory immunoassay and found acceptable results. POCT assays for cTnI should be implanted in emergency settings to ensure the fast triage of patients with chest pain, as well as timely diagnosis.

Analytical characterization of the Siemens Dimension EXL high-sensitivity cardiac troponin I assay.

Siemens Healthcare Diagnostics has four commercially available assays on different analytical platforms using different methodologies to generate signal. We assessed the analytical performance of the Dimension EXL hs-cTnI assay (LOCI method) across different matrices and compared it to two different acridinium ester-based hs-cTnI assays (ADVIA Centaur and Abbott ARCHITECT).The analytical sensitivity and precision below the 99th-percentile was determined for the Dimension EXL hs-cTnI assay. Method comparisons were performed between the Dimension EXL contemporary cTnI and the hs-cTnI assays, between different matrices for the EXL hs-cTnI assay (serum, lithium heparin and EDTA plasma), and between different hs-cTnI assays (EXL versus ADVIA Centaur or Abbott ARCHITECT) using non-parametric analyses.The limit of blank and detection were 0.9 ng/L and 1.7 ng/L, respectively, with imprecision of 5.8% at 8.6 ng/L and 3.2% at 47.5 ng/L. Comparison between the EXL contemporary cTnI and hs-cTnI assay (range: 2.6-4214 ng/L) yielded proportional lower concentrations for the hs-cTnI assay (slope = 0.86; 95%CI: 0.81 to 0.96, n = 40); however, there was no difference in concentrations below 100 ng/L between the assays (median difference = -2.7 ng/L; 95%CI: -9.8 to 9.3). Passing-Bablok regression analysis with EDTA plasma yielded proportionally higher concentrations with the EXL hs-cTnI versus Abbott hs-cTnI (slope = 1.45; 95%CI: 1.02-1.86, n = 40) with proportionally lower concentrations with EDTA versus lithium heparin plasma with the EXL hs-cTnI assay alone (slope = 0.93; 95%CI: 0.90 to 0.99, n = 40). Comparison with Abbott hs-cTnI concentrations below 100 ng/L in the three matrices, indicated that the EXL hs-cTnI assay yielded higher concentrations (median difference range: 3.4-9.4 ng/L), with differences also evident when comparing the EXL hs-cTnI assay to the ADVIA Centaur hs-cTnI assay.The Siemens EXL hs-cTnI assay meets the analytical criteria for a high-sensitivity assay, with assay specific cutoffs important to maximize clinical performance.

Analytical performance of the new Siemens NT-proBNP assays on the Advia Centaur XPT compared to the NT-proBNP method on the Dimension Vista.

Are serum leptin levels predicted by lipoproteins, vitamin D and body composition?

Both obesity and vitamin D deficiency are important health issues in Pakistan. The connection between body composition, Vitamin D and leptin in young adults is important to be studied as body composition may affect bone health and therefore the possibility of osteoporosis in later life. Few studies have attempted to investigate the effect of body composition and leptin with vitamin D in adolescence.To investigate the association of serum leptin with body composition, lipids and 25-hydroxyvitamin D (25OHD) in adults.This cross-sectional study was conducted on 167 apparently healthy adults. Demographics were recorded, bioelectrical impedance analysis was performed and clinical history noted. Serum leptin was measured using DIA source kit on ELISA and total 25OHD was measured on ADVIA-Centaur; Siemens. Total cholesterol and high density lipoprotein cholesterol were quantified using Enzymatic Endpoint Method and Cholesterol Oxidase-Phenol Aminophenazone method respectively. Biochemical analysis was done in the Departments of Pathology and Laboratory Medicine and Biological and Biomedical Sciences, Aga Khan University Hospital Karachi Pakistan.
Median age of the group (n = 167) was 20 years (IQR 27-20); 55.7% were females. Majority (89.2%, n = 149) of the study group was 25OHD deficient, 6% (n = 10) had insufficient serum 25OHD levels and 4.8% (n = 8) had sufficient D levels. Females, had higher median leptin levels [2.71 (IQR 4.76-1.66 ng/mL)] compared to their counterparts [1.3 (3.60-0.54 ng/mL), P < 0.01]. Multiple regression analysis suggested that basal metabolic rate, muscle mass, body fat percent, bone mass and serum 25OHD were the most contributing factors to serum leptin levels. Bone mass and serum 25OHD in fact bore a negative correlation with leptin.
The results indicate that basal metabolic rate, muscle mass, body fat percent, bone mass and serum 25OHD have an impact on serum leptin. Being a cross sectional study causal relationship between leptin and other variables could not be determined.
A comparison of biotin interference in routine immunoassays on the Roche Cobas 8000, Beckman Coulter DXi and Siemens Advia Centaur XPT immunoassay platforms.

Evaluation of a sensitive cardiac troponin I assay as a screening test for the diagnosis of hypertrophic cardiomyopathy in cats.

Hypertrophic cardiomyopathy (HCM) is the most common cardiac disease in cats. However, most cats are not diagnosed until they develop congestive heart failure, arterial thromboembolism (ATE), or sudden cardiac death. Thus, an affordable screening test for early detection of HCM is desirable.Evaluation of a sensitive cardiac troponin I (cTnI) assay as a screening test for HCM in cats and determination of a cutoff for its early detection.One hundred sixty-six client-owned cats (male, n = 97) of various breeds were evaluated and classified using echocardiography as being healthy (n = 87), equivocal (n = 15), or having HCM (mild, n = 16; moderate, n = 10; severe, n = 34) or ATE (n = 4).All cats were prospectively evaluated by echocardiography, and serum cTnI concentration was determined using the currently most sensitive assay (Siemens ADVIA Centaur TnI-Ultra).The median cTnI concentration was significantly different between study groups (P < .000001). A cutoff of 0.06 ng/mL provided good discrimination between healthy cats and cats with HCM (sensitivity, 91.7%; specificity, 95.4%; area under the curve [AUC], 0.95; 95% confidence interval [CI], 0.899-0.978). Even for asymptomatic cats with HCM, sensitivity and specificity for a cutoff of >0.06 ng/mL remained high at 87.8% and 95.4%, respectively (AUC, 0.93; 95% CI, 0.864-0.964).Cardiac troponin I can be used as a sensitive and specific screening test for the diagnosis of HCM in otherwise healthy cats (cutoff, >0.06 ng/mL). However, echocardiography is needed to confirm the diagnosis.

Analytical performance of a single epitope B-type natriuretic peptide sandwich immunoassay on the Minicare platform for point-of-care diagnostics.

Point-of-care B-type natriuretic peptide (BNP) testing with adequate analytical performance has the potential to improve patient flow and provide primary care givers with easy-to-use advanced diagnostic tools in the management of heart failure. We present the analytical evaluation of the Minicare BNP immunoassay under development on the Minicare I-20 platform for point-of-care testing. Analytical performance was evaluated using EDTA venous whole blood, EDTA plasma and capillary whole blood. Method comparison with a lab-testing system was performed using samples from 187 patients. Normal values were determined based on 160 healthy adults, aging from 19 to 70 years. Limit of blank (LoB), limit of detection (LoD) were determined to be 3.3 ng/L, 5.8 ng/L. Limit of quantitation (LoQ) in whole blood at 20% and 10% coefficient of variation (CV) was found < 9 ng/L and <30 ng/L respectively without significant differences between EDTA whole blood and EDTA plasma. Total CV was found to be from 6.7% to 9.7% for BNP concentrations between 92.6 and 3984 ng/L. The sample type comparison study demonstrated correlation coefficients between 0.97 and 0.99 with slopes between 1.03 and 1.09 between the different samples. Method comparison between Minicare BNP and Siemens ADVIA Centaur BNP demonstrated a correlation coefficient of 0.92 with a slope of 1.06. The 97.5% URL of a healthy population was calculated to be 72.6 ng/L. The Minicare BNP assay is a robust, easy-to-use and sensitive test for rapid determination of BNP concentrations that can be used in a near-patient setting.
Evaluation of 99th percentile and reference change values of the hs-cTnI method using ADVIA Centaur XPT platform: A multicenter study.

According to quality specifications required by international guidelines, the evaluation of the 99th URL value is a very difficult task that is usually beyond the capacity of a single laboratory. The aims of this article are to report and discuss the results of a multicenter study concerning the evaluation of the 99th percentile URL and reference change (RCV) of the ADVIA Centaur High-Sensitivity Troponin I (TNIH), recently distributed to the Italian clinical laboratories.The reference population evaluated with ADVIA XPT method for the calculation of cTnI reference distribution parameters consisted of 1325 healthy adults subjects (age range from 18 to 86 years), including 653 women (mean age 50.7 years, SD 14.5 years) and 672 men (mean age 50.9 years, SD 13.8 years), well matched for both age (P = .8112) and sex (F/M = 0.97).cTnI distribution values of reference population was highly skewed, while log-transformed cTnI values roughly approximated a log-normal distribution. Men have higher cTnI values than women throughout all the adult lifespan. Moreover, the subjects with age ≤ 55 years had significantly lower cTnI values than those with age > 55 years (p < .0001). Of note, 62% of women and 77% of men had equal or higher than cTnI values than the LoD value of the method (i.e., 2.2 ng/L).The results of the present study demonstrate that the ADVIA Centaur High-Sensitivity Troponin I using the XPT automated platform fits both the criteria and quality specifications required by the most recent international guidelines for high-sensitivity methods for cTnI assay.
Performance of LC-MS/MS and immunoassay based 24-h urine free cortisol in the diagnosis of Cushing’s syndrome.

24-h urine free cortisol (UFC) is an indicator of integrated cortisol secretion and established screening tool for Cushing’s syndrome (CS). Doubts have been raised regarding specificity of immunoassays, and mass spectrometric techniques have been proposed as an alternative. In the present study we compared diagnostic accuracy of UFC measured with LC-MS/MS vs. immunoassay in patient with CS and patients where CS has been excluded. We examined 24-h urine samples from patients with surgically confirmed CS (n = 77; Cushing’s disease (n = 44), ectopic CS (n = 5), adrenal CS (n = 28)) and patients in whom Cushing’s syndrome was excluded (n = 97) by long-term follow up. UFC was first measured by automated chemiluminescence immunoassays (ADVIA Centaur, Siemens; LIAISON, DiaSorin). Aliquots of all samples were also analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Statistics: Passing-Bablok Regression, Receiver operating characteristic (ROC) analysis with Youden’s index calculation. UFC of CS patients were higher with both immunoassays compared to LC-MS/MS (913 +/- 235 vs. 303 +/- 155 μg/24 h (ADVIA) and 898 +/-216 vs. 399 +/- 196 μg/24 h (LIAISON)). Similarly, UFC were higher with immunoassays than with LC-MS/MS in the control group (223 +/- 10 vs. 23 +/- 2 μg/24 h (ADVIA) and 105 +/- 6 vs. 27 +/- 4 ug/24 h for (LIAISON)). Passing-Bablok regression showed good correlation between LC-MS/MS and ADVIA as well as between LCMS/MS and LIAISON (r = 0.96 and r = 0.99, p < 000.1) but less correlation in controls (r = 0.83 and r = 0.74, respectively, p < 000.1). ROC calculation revealed the highest ROC AUC (0.89) for the LIAISON immunoassay, followed by LC-MS/MS (0.82) and the ADVIA (0.80). In direct comparison, AUCs from LC-MS/MS and immunoassays in the same patient were not statistically different (p < 0,001). Best cut-off concentration to identify patients with CS was 234 μg/24 h (LIAISON), 51 μg/24 h for LC-MS/MS and 330 μg/24 h (ADVIA Centaur). In summary, UFC values were measured substantially higher by both immunoassays compared to LC-MS/MS. This is most likely due to cross-reactivity from interfering glucocorticoid metabolites. Nevertheless, all three methods correlated well. ROC analysis revealed the highest AUC for one of the immunoassays, although differences between the three methods were not significant. Direct comparison with LC-MS/MS indicates that high diagnostic accuracy can be obtained with suitable immunoassays.

Individualization of treatment with gentamicin in neonates based on drug concentration in the blood serum.

Aim: To evaluate how useful it is to make measurements of gentamicin concentrations in newborns’ blood in order to optimize antibiotic therapy.Material and methods: 73 newborns empirically treated with gentamicin, in doses consistent with the Neofax® guidelines. There were 152 measurements of maximum and minimum serum gentamicin concentrations. Samples were determined based on the chemiluminescence technique on the Siemens Advia Centaur analyzer. The concentrations of gentamicin that were measured were compared with various therapeutic ranges used in the literature.Results: According to the standards adopted in the University Hospital in Wrocław, the maximum concentration was reached in 38.16% of all the children, while the minimum in 26.32%. In other children the concentrations were below or above the therapeutic range. According to the Neofax® guidelines, the intended maximum concentration was observed in 71.05% of the newborns, and the minimum in 32.89%. The minimum concentration of <2 mg/L was found in 93.42% of the newborns, while >2 mg/L was determined in 33.33%, despite a 48-hour dosing interval. These were premature babies (<28th week of gestational age) and 55.56% of them reached a maximum concentration of 5-12 mg/L. There was no significant correlation between maximum or minimum concentration and gestational age or body weight.Conclusions: 1. The dosage of gentamicin in newborns according to the Neofax® recommendations does not ensure achieving the intended serum antibiotic concentrations. 2. In order to optimize gentamicin therapy in newborns it is necessary to individualize the dose based on measurements of drug concentrations in the blood and pharmacokinetic calculations.
Performance of a novel high sensitivity cardiac troponin I assay in asymptomatic hemodialysis patients – evidence for sex-specific differences.

Background High sensitivity assays for the determination of cardiac troponin I (cTnI) are able to reliably measure cTnI far below the 99th percentile of healthy persons (hs-cTnI) and display sex-specific differences. There is uncertainty regarding the clinical utility of hs-cTnI in asymptomatic hemodialysis (HD) patients and if sex-specific differences also apply in this cohort. Methods In this multicenter study we measured hs-cTnI and sensitive cTnI (s-TnI) concentrations (both on Siemens Centaur) in 215 HD patients from a predialytic sample to determine the prevalence of elevated concentrations above the 99th percentile, the association with baseline characteristics, prognostic accuracy for death, and sex-specific differences. Results Hs-cTnI and s-cTnI concentrations were below the 99th percentile in 93% and 85% of patients with a median concentration of 12 ng/L (interquartile range 7-66) and 19 ng/L (12; 31, p < 0.0001). Hs-cTnI and s-cTnI concentrations were independently associated with age (p < 0.05) and ischemic cardiac disease (p < 0.05), but not with residual renal function. Both hs-cTnI and s-cTnI were predictors of death after median follow-up of 2.6 years with an AUC of 0.733 and 0.744, respectively (both p < 0.0001). Important sex-differences emerged for hs-cTnI, but not for s-cTnI: first, women had significantly lower hs-cTnI concentrations than men (p = 0.03); second, hs-cTnI had significantly higher prognostic accuracy for death in women than for men (AUC 0.824 vs. 0.674, p = 0.04). Conclusions The majority of HD patients have (h)s-cTnI concentrations below the 99th percentile. High normal values are predictive of death. Hs-cTnI allows to elucidate important sex-differences in HD patients with lower concentrations and higher prognostic accuracy in women.

Sample matrix and high-sensitivity cardiac troponin I assays.

Background Manufacturers of high-sensitivity cardiac troponin (hs-cTn) assays have restricted use of what sample types or matrices are acceptable to use for measurement. Our goal was to evaluate the comparability of the Siemens ADVIA Centaur hs-cTnI assay across different matrices and under different storage conditions. Methods Three different QC-plasma matrices were evaluated for imprecision <10 ng/L. Passing-Bablok regression and difference plots were determined for cTnI concentrations spanning the reference interval (limit of quantification to male 99th-percentile: 2.5 ng/L to <60 ng/L) between serum and lithium heparin plasma, lithium heparin and EDTA plasma and between the Siemens and Abbott hs-cTnI assays. Stability at room temperature (RT) and 2-8 °C was also assessed across the three matrices. Results Over 16-weeks the SDs were ≤1.0 ng/L for QCs ranging from 5.0 to 8.3 ng/L. Across the reference interval there was excellent agreement between lithium heparin plasma and serum for the Siemens hs-cTnI assay (slope=0.98/intercept=-0.1), however, cTnI concentrations were proportionally lower in EDTA as compared to lithium heparin plasma (slope=0.90, 95% CI: 0.88-0.92). In lithium heparin plasma the Siemens hs-cTnI concentrations were higher than the Abbott hs-cTnI concentrations (slope=1.26/intercept=-0.2). Stability of cTnI in lithium heparin plasma as compared in serum and EDTA plasma appeared more labile, with decreases ≥20% in concentrations evident as early as 1-day in storage at RT. Conclusions There is excellent agreement in concentrations between lithium heparin plasma and serum with the Siemens ADVIA Centaur hs-cTnI assay; however, cTnI concentrations in EDTA plasma are lower. Reference intervals and clinical studies in EDTA plasma for the Centaur hs-cTnI assay are required before clinical use.

Comparison of Six Automated Immunoassays With Isotope-Diluted Liquid Chromatography-Tandem Mass Spectrometry for Total Thyroxine Measurement.

Accurate serum total thyroxine (TT4) measurement is important for thyroid disorder diagnosis and management. We compared the performance of six automated immunoassays with that of isotope-diluted liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS) as the reference method. We also evaluated the correlation of thyroid stimulating hormone (TSH) with TT4 measured by ID-LC-MS/MS and immunoassays.Serum was collected from 156 patients between October 2015 and January 2016. TT4 was measured by immunoassays from Abbott (Architect), Siemens (ADVIA Centaur XP), Roche (E601), Beckman-Coulter (Dxi800), Autobio (Autolumo A2000), and Mindray (CL-1000i), and by ID-LC-MS/MS. Results were analyzed using Passing-Bablok regression and Bland-Altman plots. Minimum requirements based on biological variation wer

e as follows: a mean bias of ≤4.5% and total imprecision (CV) of ≤3.7%.All immunoassays showed a correlation >0.945 with ID-LC-MS/MS; however, the slope of the Passing-Bablok regression line varied from 0.886 (Mindray) to 1.23 (Siemens) and the intercept from -12.8 (Siemens) to 4.61 (Mindray). Only Autobio, Beckman-Coulter, and Roche included the value of one in the 95% confidence interval for slope. The mean bias ranged from -10.8% (Abbott) to 9.0% (Siemens), with the lowest value noted for Roche (3.5%) and the highest for Abbott (-10.8%). Only Abbott and Roche showed within-run and total CV ≤3.7%.Though all immunoassays correlated strongly with ID-LC-MS/MS, most did not meet the minimum clinical requirement. Laboratories and immunoassay manufacturers must be aware of these limitations.
Artificial Intelligence and Radiology in Singapore: Championing a New Age of Augmented Imaging for Unsurpassed Patient Care.

Artificial intelligence (AI) has been positioned as being the most important recent advancement in radiology, if not the most potentially disruptive. Singapore radiologists have been quick to embrace this technology as part of the natural progression of the discipline toward a vision of how clinical medicine, empowered by technology, can achieve our national healthcare objectives of delivering value-based and patient-centric care. In this article, we consider 3 core questions relating to AI in radiology, and review the barriers to the widespread adoption of AI in radiology. We propose solutions and describe a “Centaur” model as a promising avenue for enabling the interfacing between AI and radiologists. Finally, we introduce The Radiological AI, Data Science and Imaging Informatics (RADII) subsection of the Singapore Radiological Society. RADII is an enabling body, which together with key technological and institutional stakeholders, will champion research, development and evaluation of AI for radiology applications.

Validation of plasma thyroxine and triiodothyronine methods on the ADVIA Centaur® XP.

Standardization programs for thyroid hormones have revealed bias between immunochemical methods and the reference method ED-ID-LC/MS. Lack of standardization between methods, suboptimal reference intervals and replacement of serum with plasma may compromise the capability of the immunochemical thyroid methods to diagnose thyroid disease. To accommodate the demand for faster turn-around times for laboratory replies, we replaced serum with plasma on some serum CE marked thyroid methods. This forced us to do on-board analytical correction for the plasma total T4 (TT4) method on ADVIA Centaur® XP. We, next, validated the capability of the ADVIA Centaur® XP thyroid methods on plasma by (1) first carrying out a prospective method comparison with the ED-ID-LC/MS reference method using collected plasma samples, (2) we verified the clinical reference intervals by analyzing collected plasma samples from healthy individuals, and (3) retrospectively compared laboratory results from two different time periods using serum TT4 and serum total triiodothyronine (TT3) versus plasma free thyroxine (FT4) and plasma TT3, respectively, to diagnose thyroid disease. The plasma FT4 method displayed a negative concentration-dependent bias against the reference method. This bias was apparently counteracted by a fitted reference interval for the plasma FT4 method. Indeed, overt hyperthyroid disease was found in 1.0% and 1.1% of the cases using serum and plasma and overt hypothyroid condition were in 1.3% and 0.6% of the cases using serum and plasma, respectively. In conclusion, the ADVIA Centaur® XP FT4 method displayed a negative bias at high plasma FT4 concentrations against the reference method, but the diagnostic performance was not compromised due to a fitted reference interval.
Pregnancy Week-Specific Reference Ranges for Thyrotropin and Free Thyroxine in the North Denmark Region Pregnancy Cohort.

Physiological changes in maternal thyroid function during pregnancy necessitate the use of pregnancy-specific reference ranges. Dynamic changes in thyrotropin (TSH) within the first trimester of pregnancy have been reported, but more evidence is needed to substantiate the findings. The objective of this study was to estimate pregnancy week-specific reference ranges for maternal TSH and free thyroxine (fT4) in early pregnancy.The study consecutively recruited serum residues from blood samples collected as part of the prenatal screening in the North Denmark Region, 2011-2015. TSH, fT4, thyroid peroxidase antibodies (TPOAb), and thyroglobulin antibodies (TgAb) were measured using an ADVIA Centaur XPT immunoassay. The reference cohort included 10,337 pregnant women who had no thyroid disease or other autoimmune diseases and were TPOAb- and TgAb negative. The main outcome measures were lower and upper reference limits (2.5th and 97.5th percentiles) for TSH and fT4 stratified by week of pregnancy.Blood samples were drawn in pregnancy weeks 4-20 (median week 10), and 92% of the pregnancies ended with a live birth. TSH varied considerably in the first trimester of pregnancy, and the levels were highest in early pregnancy (weeks 4-6: 0.6-3.7 mIU/L) followed by a gradual decline to lower levels in weeks 9-11 (0.1-2.8 mIU/L) and 12-14 (0.03-2.8 mIU/L). Maternal fT4 showed less variation (weeks 4-6: 12-20 pmol/L; weeks 9-11: 13-21 pmol/L; weeks 12-14: 13-20 pmol/L).The results corroborate dynamic week-specific changes in maternal TSH in early pregnancy. The use of uniform lower and upper reference limits for TSH in early pregnancy may be too simple.

Evaluation of nutritional status in children with amblyopia.

We aimed to compare the body mass index and vitamin and mineral status of children with and without amblyopia.Amblyopic children aged between 5 and 18 years (n=46) and age-matched control children (n=32) were evaluated in terms of anthropometric parameters, including height, weight, body mass index and demographic features. Serum vitamin B12 and folate were measured using an Advia Centaur XP (Siemens, Ireland) biochemistry analyzer. We evaluated the inorganic mineral elements from hair samples with inductively coupled plasma-mass spectrometry using a Thermo XSeries 2 analyzer (Thermo Fisher Scientific, Bremen, Germany).No significant difference was found between the two groups in terms of height, weight, and body mass index or serum B12 and folate concentrations (p>0.05). Children with severe amblyopia had lower vitamin B12 and folate and higher body mass index. The levels of phosphorus (p=0.012), selenium (p=0.002), molybdenum (p<0.001), iodine (p=0.002), chromium (p=0.022), boron (p<0.001), and beryllium (p=0.005) were all significantly lower in the amblyopia group compared to the control group. All of these minerals, except phosphorus, were also significantly lower in those with severe amblyopia compared to those with milder amblyopia and controls (p<0.05).Amblyopic children are significantly deficient in some inorganic elements. Inorganic elements, vitamin B12, and folate may play an important role in the visual development of amblyopic children.

Vancomycin immunoassay: does the Advia Centaur XPT underestimate the exposure of patients? A method comparison study.

Paper microfluidic device for early diagnosis and prognosis of acute myocardial infarction via quantitative multiplex cardiac biomarker detection.

The early detection of acute myocardial infarction (AMI) upon the onset of chest pain symptoms is crucial for patient survival. However, this detection is challenging, particularly without a persistent elevation of ST-segment reflected in an electrocardiogram or in blood tests. A majority of the available point-of-care testing devices allow accurate and rapid diagnosis of AMI. However, AMI diagnosis is reliable only at intermediate and later stages, with myocardial injury (> 6 h) and MI, based on the expression of specific cardiac biomarkers including troponin I or T (cTnI or cTnT), creatine kinase-MB (CK-MB), and myoglobin. Diagnosis at the early myocardial ischemia stage is not possible. To overcome this limitation, a sensitive and rapid microfluidic paper-based device (µPAD) was developed for the simultaneous detection of multiple cardiac biomarkers for the early and late diagnosis of AMI. The glycogen phosphorylase isoenzyme BB (GPBB) was detected during early (within first 4 h) ischemic myocardial injury. On the same µPAD platform, detection of prolonged elevation of levels of cTnT and CK-MB, which are only produced 6 h after the onset of chest pain in human serum, was possible. Sandwich immunoassay performed on the µPAD achieved reproducibility (RSD approximately 10% and intra-and inter-day precision (CV 10-20%, 99th percentile), as well as consistently stable test results for 28 days, with strong correlation (r2= 0.962), using the standard Siemens Centaur XPT Immunoassay system. The present findings indicate the potential of the µPAD platform as a point-of-care device for the early diagnosis and prognosis of AMI.

Oestradiol measurement during fulvestrant treatment for breast cancer.

Biochemical evaluation of menopausal status is used to inform treatment decisions, including clinical trial eligibility in women with oestrogen receptor positive breast cancer. However, fulvestrant may interfere with oestradiol immunoassays and confound accurate assessment in this context. We conducted a service evaluation of two immunoassays and an LC-MS/MS assay to determine the extent of the interference. Serum oestradiol levels were analysed by two immunoassays (Siemens Centaur XP and Abbott Architect) and liquid chromatography-tandem mass spectrometry (LC/MS/MS). Immunoassay gave higher serum oestradiol results than LC-MS/MS at low concentrations, with improved analytical sensitivity demonstrated by LC-MS/MS. Cross-reactivity of fulvestrant was observed for each immunoassay. We have shown that two commonly used immunoassays do not demonstrate the required sensitivity or specificity for the measurement of oestradiol in a breast cancer population. For patients receiving fulvestrant, spurious results may be generated that could impact treatment decisions. LC-MS/MS is recommended in this setting.

Elevated serum HER-2 predicts poor prognosis in breast cancer and is correlated to ADAM10 expression.

Human epidermal growth factor receptor-2 (HER-2) overexpression in breast tumor tissues is associated with a poor prognosis but may benefit from treatment with trastuzumab. The extracellular domain (ECD) of HER-2 can be measured in serum and which has been a new inspection item in clinical laboratory of several hospitals. However, whether serum HER-2 ECD can be a marker of HER-2 status in tumor tissues still confused clinicians. This study is a retrospective observation to explore the correlation between serum HER-2 ECD shedding and tissue HER-2 status in breast cancer patients. Meanwhile, we will further uncover the potential clinical significance of serum HER-2 ECD detection. A total of 545 unselected breast cancer patients from Fudan University Shanghai Cancer Center were enrolled in this study. At primary diagnosis without any treatment, serum HER-2 ECD was measured on ADVIA Centaur assay; meanwhile, tissue HER-2 from core needle biopsy was tested through immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH). We showed that serum HER-2 ECD concentration was related to tissue HER-2 status. Nevertheless, 36.9% of patients with tissue HER-2 overexpression had low levels of HER-2 ECD shedding (<15 ng/mL) in serum. Here, we demonstrated that HER-2 ECD shedding was also associated with protein expression and alpha-secretase activity of a disintegrin and metalloproteinase 10 (ADAM10) using tumor tissues and cell lines. Progression-free survival (PFS) data from breast cancer patients in TNM phase II and III with tissue HER-2 IHC 3+ were analyzed using Kaplan-Meier plotter. The patients with serum HER-2 ECD above 15 ng/mL had lower progression-free survival than those with serum HER-2 ECD <15 ng/mL. Thus, serum HER-2 ECD could be a biomarker to identify the subgroup of poorer outcome among HER-2 overexpression breast cancer patients. Inhibition of ADAM10 activity may have potential therapeutic benefit for this most aggressive tumor subgroup.
Burnout: of Centaurs, Poisoned Arrows, and Nautilus Shells.

Clinical Features and Prognosis of Patients with Acute and Chronic Myocardial Injury Admitted to the Emergency Department.

This study aimed to investigate the clinical features and prognosis of acute and chronic myocardial injury without clinical evidence of myocardial infarction in patients admitted to the emergency department.We analyzed the clinical data of all consecutive patients admitted to the emergency department during the years 2012 and 2013 who had at least 2 determinations of troponin I (TnI Ultra Siemens, Advia Centaur) and without a diagnosis of myocardial infarction. Clinical events were evaluated in a 3-year follow-up.A total of 1201 patients met the study’s inclusion criteria and were included in the analysis (833 with cTnI below the 99th percentile, 261 with acute myocardial injury, and 107 with chronic myocardial injury). During a median follow-up of more than 36 months, mortality and rehospitalization for heart failure were significantly higher in patients with acute or chronic myocardial injury compared with patients without myocardial injury. No differences were observed in overall mortality between patients with acute and chronic myocardial injury, or in the rate of readmission due to acute coronary syndrome. However, the risk of readmission due to heart failure (adjusted HR 2.17; 95% confidence interval, 1.26-3.75; P = .005) was higher in patients with chronic myocardial injury.Mortality in long-term follow-up is high and similar in acute and chronic myocardial injury; however, the risk of readmission due to heart failure is higher in patients with chronic myocardial injury compared with patients with acute myocardial injury.

Evaluation of a high-sensitivity cardiac troponin I assay compared to a first-generation cardiac troponin I assay in Doberman Pinschers with and without dilated cardiomyopathy.

Echocardiography and 24-hour ECG are the gold standard tests to diagnose dilated cardiomyopathy (DCM) in Doberman Pinschers (DP), but myocardial damage might be detected earlier using a high-sensitivity cardiac troponin I (hs-cTnI) assay.To evaluate and compare an hs-cTnI assay (Advia Centaur TnI-Ultra assay) with a conventional cTnI assay in DP with different stages of DCM and in healthy DP.Three hundred forty-five examinations from 162 DP with and 179 DP without DCM.Prospective longitudinal study. Dogs were allocated into 6 groups based on echocardiographic and 24-hour ECG criteria: (1) healthy group (179 dogs), (2) last-normal group (29 dogs), which included dogs that were considered to be healthy at the time of their examination but were assigned to the last-normal group retrospectively when DCM was diagnosed at their next examination within 1.5 years, (3) only arrhythmias (45 dogs, 119 examinations), (4) only echocardiographic changes (24 dogs, 61 examinations), (5) echocardiographic changes with ventricular premature complexes (41 dogs, 100 examinations), and (6) decompensated (23 dogs, 36 examinations). Hs-cTnI and conventional cTnI concentration measurements were performed and compared.A cutoff value of hs-cTnI concentration >0.113 ng/mL had a sensitivity of 81.2% and a specificity of 73.2% to identify the presence of DCM. The conventional cTnI assay showed a similar test performance, but the hs-cTnI assay identified more dogs (21/29 dogs, 72%) in the last-normal group compared to the conventional cTnI test (18/29 dogs, 62%).The hs-cTnI is an additional test with good potential to identify early DCM.

Analytical validation of a conventional cardiac troponin I assay for dogs and cats.

Cardiac troponins are gold-standard biomarkers of myocardial injury. There is a need for validation of assays with higher availability and lower costs in veterinary medicine.The primary aim of the present study was to perform an analytical validation of the IMMULITE 2000 TnI assay for use in dogs and cats. A secondary aim was to evaluate its agreement with the previously validated and sensitive Siemens ADVIA Centaur TnI-Ultra assay.Intra- and inter-assay variation, detection limits, the linearity under dilution, and a sample addition study (modified spike-and-recovery analysis) were investigated to assess analytical performance in 15 canine and 15 feline serum samples. Agreement between the assays was evaluated by correlation and Bland-Altman analyses including an additional 99 canine serum samples.Intra-assay variation of cTnI in canine and feline serum was 3.71% and 4.68%, while inter-assay variation was 5.88% and 6.54%, respectively. The assay performed with acceptable linearity within a clinically relevant range of serum cTnI concentrations. The sample addition study revealed insufficient recovery in the range of 71.9%-81.4% for dogs and 62.6%-75.7% for cats. This was considered to be due to a negative matrix effect. A significant correlation between the assays was found, and the Bland-Altman analysis showed acceptable agreement for a wide range of concentrations, but revealed a proportional error, with the IMMULITE TnI assay consistently measuring a higher concentration than the Centaur TnI-Ultra assay. This was relevant only at high serum cTnI concentrations.The IMMULITE TnI assay is considered acceptable for clinical use in dogs and cats.

Performance evaluation of nine different syphilis serological tests in comparison with the FTA-abs test.

Serological methods have great importance for the detection of Treponema pallidum antibodies in syphilis diagnosis. The goal of the present study is to evaluate various commercially available screening assays in comparison with the FTA-abs test.
A total of 363 serum samples were enrolled in the study. Following routine testing including RPR and TPHA tests, each sample was tested by treponemal immunoassays (Chorus Syphilis Screen Recombinant, Architect Syphilis TP, Syphilis Virclia Monotest, Siemens Advia Centaur Syphilis, Euroimmun Treponema pallidum Screen ELISA, Vircell Syphilis ELISA IgG + IgM, SD Bioline Syphilis). The result obtained from each test was compared with the confirmatory FTA-abs test. Kappa (κ) coefficients were used to compare the concordance of the tests.
When the various tests were evaluated in comparison with the FTA-abs test, the sensitivity, specificity and percent agreement of each test were as follows: Architect Syphilis TP, 92.3%, 94.5%, 92.8%; Chorus Syphilis Screen Recombinant, 87.9%, 91.2%, 88.7%; Syphilis Virclia Monotest, 80.5%, 97.8%, 84.9%; Siemens Advia Centaur Syphilis, 87.5%, 89%, 87.9%; Euroimmun Treponema pallidum Screen ELISA, 87.5%, 85.7%, 87.1%; Vircell Syphilis ELISA IgG + IgM, 73.2%, 62.6%, 70.5%; TPHA, 89%, 63.7%, 82.6%; SD Bioline Syphilis, 58.1%, 94.5%, 67.2%; RPR test, 57.7%, 57.1%, 57.6%.
The results of the present study show that Treponema pallidum specific immunoassays with a performance similar or better than TPHA test generally performed well with the confirmatory FTA-abs test and may be an alternative for screening total antibodies in syphilis infection.
Evaluation of performance characteristics of hepatitis B e antigen serologic assays.

Hepatitis B e antigen (HBeAg) is considered an indicator of high hepatitis B virus (HBV) replication. Performance characteristics of commercially available HBeAg assays have not been determined, thus it is unknown whether lack of HBeAg detection is because of test sensitivity or HBV basal core promoter and precore mutations.
We studied the correlation between HBeAg reactivity with HBV DNA levels in three commercially available HBeAg assays using 335 HBsAg and HBV DNA positive serum/plasma samples.
Diagnostic sensitivity was determined by serial dilutions of a WHO HBeAg standard. The limit of HBeAg detection estimated through regression was 1 IU/mL (Centaur), 97 IU/mL (DiaSorin) and 129 IU/mL (Vitros). Of these 335 samples, enough sample volume remained in 253 samples for head-to-head comparison of the assays.
81 (32%), 41 (16%) and 36 (14%) of the samples were HBeAg positive by the Centaur, DiaSorin and Vitros assays, respectively. Compared to the FDA-approved Centaur assay the specificity of the other two assays was 98%, while sensitivity was 47% for the DiaSorin assay and 41% for the Vitros assay. Significant association was found between HBeAg positive samples and HBV DNA levels>>20,000 IU/mL; 31% of HBeAg negative samples (Centaur) had HBV DNA levels>>20,000 IU/mL, 26% of HBeAg positive samples had HBV DNA levels <20,000 IU/mL and 5 HBeAg positive samples had HBV DNA levels <2000 IU/mL.
Discordance was seen between these HBeAg assays, indicating reliance on HBeAg alone as a marker of high HBV replication can be misleading. Detection and quantification of HBV DNA remains the accurate and reliable marker of HBV replication.

Vitamin D levels in a pediatric population of a primary care centre: a public health problem?

Vitamin D deficiency is a public health problem that occurs more frequently than expected. The aim of this study is to evaluate the vitamin D levels of children attending the paediatrics unit of the Bertamiráns primary care centre (A Coruña NW Spain). This is an observational study carried out during 1 year on a random sample of the pediatric population aged between 5 and 15 years. The levels of vitamin D (25(OH)D) were determined by immunoassay (ADVIA Centaur Vitamin D®). The results were classified as sufficient >> 20 ng/ml), insufficient (10-20 ng/ml) and deficient (< 10 ng/ml).
153 analyses of vitamin D were carried out (58.2% in girls and 41.8% in boys), distributed in two age groups: 5-10 (62) and 10-15 (91). 66% of the total of the sample presented some degree of vitamin D deficit (60.1% insufficient (92) and 5.9% (11) deficient). In Galicia, there is a high prevalence of vitamin D deficiency/insufficiency in the healthy population, which increases if the patients present some kind of chronic pathology, thus leading to a public health problem. It is advisable to increase the consumption of fortified foods and/or to reconsider the administration of vitamin supplements.
Laboratory and Clinical Performance of the ADVIA Centaur Anticyclic Citrullinated Peptide Assay for Rheumatoid Arthritis Diagnosis.

Anticyclic citrullinated peptide antibodies are important serologic markers for the diagnosis of rheumatoid arthritis. Several kinds of test reagents for automated immunoassay systems have been developed and used in recent years.
To evaluate the analytic and diagnostic performance of the new ADVIA Centaur anticyclic citrullinated peptide assay (Siemens Healthineers, Erlangen, Germany) compared with the Elecsys assay (Roche Diagnostics, Mannheim, Germany).
A total of 576 serum samples were collected from subjects, including 156 patients (27%) with rheumatoid arthritis. Precision performance and analytical measurement range for the ADVIA assay were evaluated. Diagnostic performance of the 2 assays was compared based on sensitivity, specificity, and area under the receiver operating characteristic curves.
The ADVIA assay showed a within-laboratory imprecision of 3.4% coefficient of variation for levels of 3.36 and 24.99 U/mL. This assay was demonstrated to be linear from 0.4 to 180.0 U/mL. With default cutoff values, sensitivity and specificity for diagnosing rheumatoid arthritis were 71.2% and 97.9%, respectively, for the ADVIA assay and 73.1% and 96.9%, respectively, for the Elecsys assay. With the best cutoff values from the analyses of the receiver operating characteristic curve, the sensitivity of the 2 assays was the same at 75.6%. However, the specificity of the ADVIA assay was 96.4%, whereas that of the Elecsys assay was 94.3%. The area under the receiver operating characteristic curve value for the ADVIA assay was 0.867, which was not significantly different from that of the Elecsys assay (0.865).
The ADVIA Centaur anticyclic citrullinated peptide assay showed good analytic and diagnostic performance in diagnosing rheumatoid arthritis.
Brain Natriuretic Peptide in Plasma as Predictor of All-Cause Mortality in a Large Danish Primary Health Care Population Suspected of Heart Failure.

Measurement of B-type natriuretic peptide (BNP) in plasma may have its greatest potential in primary care, as general practitioners need to rapidly identify patients who warrant further medical review. The aim of the present study was to examine the prognostic information of BNP measurement on all-cause mortality in a large Danish primary care cohort.
This study covered a cohort of Danish primary care patients (n = 61665) with a median follow-up period of 4.36 years (interquartile range, 2.29-6.62 years). BNP was measured in plasma using the ADVIA Centaur/CentaurXP platform. The association of BNP with mortality was assessed with a hazard ratio for all-cause mortality from a multivariable Cox proportional hazards model.
Kaplan-Meier curves showed decreasing survival probability with increasing BNP (P < 0.001). Each doubling of BNP increased mortality by 32.3% (95% CI, 30.8-33.8) when adjusted for sex and age, and by 25.3% (95% CI, 23.8-26.8) when further adjusted for Charlson comorbidity index, hemoglobin, estimated glomerular filtration rate, glycohemoglobin, and thyroid-stimulating hormone. Also, in a subcohort (n = 10824) without biochemical signs of severe kidney failure, anemia, polycythemia, hypothyroidism or hyperthyroidism, or dysregulated diabetes, each doubling of BNP increased mortality by 28.6% (95% CI, 22.8-34.7).
Our results show that even in a primary care population, BNP measurements contain prognostic information regarding all-cause mortality.

Reference intervals for thyroid-stimulating hormone, free thyroxine, and free triiodothyronine in elderly Chinese persons.

Background Thyroid hormone levels are essential for diagnosing and monitoring thyroid diseases. However, their reference intervals (RIs) in elderly Chinese individuals remain unclear. We aimed to identify factors affecting thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) levels using clinical “big data” to establish hormone level RIs for elderly Chinese individuals. Methods We examined 6781, 6772, and 6524 subjects aged ≥65 years who underwent FT3, FT4, and TSH tests, respectively, at the Peking Union Medical College Hospital between September 1, 2013, and August 31, 2016. Hormones were measured using an automated immunoassay analyzer (ADVIA Centaur XP). RIs were established using the Clinical Laboratory Standards Institute document C28-A3 guidelines. Results The median TSH was significantly higher in women than in men; the opposite was true for median FT3 and FT4 levels. No differences were observed in TSH or FT4 by age in either sex or overall; FT3 levels significantly decreased with age. Seasonal differences were observed in TSH and FT3 levels but not FT4 levels; the median TSH was the highest in winter and lowest in summer, whereas the median FT3 was the lowest in summer (albeit not significantly). RIs for TSH were 0.53-5.24 and 0.335-5.73 mIU/L for men and women, respectively; those for FT3 were 3.76-5.71, 3.60-5.42, and 3.36-5.27 pmol/L in 64- to 74-, 75- to 84-, and 85- to 96-year-old subjects, respectively. The RI for FT4 was 11.70-20.28 pmol/L. Conclusions RIs for TSH in elderly individuals were sex specific, whereas those for FT3 were age specific.
Competitive light-initiated chemiluminescent assay: using 5-α-dihydrotestosterone-BSA as competitive antigen for quantitation of total testosterone in human sera.

This paper described a homogeneous method, light-initiated chemiluminescent assay (LICA), for quantitation of total testosterone in human sera. The assay was bead based and built on a competitive-binding reaction format, in which 5-α-dihydrotestosterone (5-α-DHT) competed with the testosterone in serum samples in binding with biotinylated anti-testosterone antibody. The more testosterone in the serum sample, the less 5-α-DHT that bonded with biotinylated anti-testosterone antibodies. 5-α-DHT was coupled with emission beads (doped with thioxene derivatives and Eu(III) as a chemiluminescence emitter) via bovine serum albumin as a linker. Once streptavidin-coated sensitizer beads (modified with phthalocyanine as a photosensitizer) were added, the streptavidin/biotin reaction between 5-α-DHT-bound anti-testosterone antibody and sensitizer beads could bring emission and sensitizer beads together, which allowed energy transfer from sensitizer bead to emission bead. As such, an exciting light (680 nm) impinging on the sensitizer beads led to light emission at 520-620 nm by emission beads. The strength of the emitted light was inversely proportional to the testosterone in serum sample. The detection range of this assay was from 13.3 to 1200 ng/dL. The coefficient variation for intra- and inter-assay was lower than 15%. The recovery of this method ranged from 95.5 to 105.9% for different samples. Moreover, the LICA assay was highly specific with low cross-reactivity and interference. The concentration of testosterone from 58 serum samples analyzed by the LICA method significantly correlated (y = 0.97x + 1.87, R2 = 0.970, p < 0.001) with those obtained with the SIEMENS Centaur Xp System. Graphical abstract ᅟ.
Evaluation of the Siemens ADVIA Centaur high-sensitivity cardiac troponin I assay in serum.

International recommendations on high-sensitivity cardiac troponin (hs-cTn) testing recommend that laboratories select only one sample type for testing. We evaluated the Siemens ADVIA Centaur hs-cTnI assay in serum and thereby provide information on imprecision, long-term storage stability, freeze-thaw stability, method comparison to other hs-cTnI assays, and clinical performance.
Patients with chest pain onset <6 h who already had Roche hs-cTnT, Beckman hs-cTnI and Abbott hs-cTnI results recorded and had non-thawed and frozen serum aliquots formed the study population (n = 134 patients with 305 serum aliquots obtained at either 0, 3 or 6 h stored below -70 °C since 2003) for measurement with the Siemens hs-cTnI assay in 2018. Receiver-operating characteristic curve analyses for myocardial infarction (MI) using the highest obtained hs-cTn concentration was performed. Additional comparison testing on serum samples stored frozen (at -70 °C for <1 month in 2018) for the Siemens and Abbott hs-cTnI assays were performed, as well as precision testing in serum pools and freeze-thaw stability testing.
The Siemens hs-cTnI assay had an area under the curve (AUC) of 0.978 (95%CI: 0.937-0.996) for MI in the study cohort (Roche hs-cTnT AUC = 0.965 and Abbott AUC = 0.973). The Siemens hs-cTnI assay yielded higher cTnI concentrations than the other hs-cTn assays, with the same proportional bias (slope = 1.4) between the Siemens and Abbott hs-cTnI assays obtained from serum samples collected in 2003 and 2018. Over 3 months, a low serum pool of 3.5 ng/l achieved a CV of 20% (SD = 0.7, n = 42) and a high serum pool of 820 ng/l achieved a CV of 2.3% (SD = 20, n = 42). Three different serum pools recovered within 10% from baseline concentration after 5 freeze-thaw cycles for the Siemens hs-cTnI assay.
In serum, the Siemens ADVIA Centaur hs-cTnI assay had excellent clinical performance for MI in an early chest pain onset population, acceptable precision at normal and highly elevated cTnI concentrations, long-term storage stability (15 y storage below -70 °C) and acceptable freeze-thaw stability, all of which supports serum as an acceptable sample type to use in clinical studies and in clinical practice.

MicroRNA-Target Interactions Reloaded: Identification of Potentially Functional Sequence Variants Within Validated MicroRNA-Target Interactions.

MicroRNAs (miRNAs) serve as critical regulators of gene expression. However, their binding to target genes can be influenced by genetic variability within the miRNA-target interaction (MTI) sites. We performed an in silico sequence reanalysis to identify novel sequence variants within MTIs with potential functional impacts. A literature search of the PubMed and the Web of Science spanning the years 2008 to April 2018 identified 240 articles reporting MTIs in humans. Sequence reanalysis of reported MTI regions was performed using the Ensembl browser. We found 76 sequence variants within 23 MTIs. We present description of MTIs wherein sequence variants are present within both the mature miRNA seed region and the miRNA target, which we termed miR-gene-target-single nucleotide polymorphism (miR-GenTar-SNP). To the best of our knowledge, this is the first report on copresence of sequence variants within both miRNA gene and the target site. In the course our analyses, the need for extension of current terminology emerged and therefore, novel terminology was introduced: miR-indel, miR-double nucleotide polymorphism (DNP), miR-TS-indel, and miR-TS-DNP. Identification of novel MTI sequence variants is a hitherto understudied, but critical dimension in understanding the complexity of interactions and gene deregulation in various complex diseases. Because such variations might profoundly affect miRNA function, they should be taken into consideration in future research that depends on “variability science” such as precision medicine, human genetics, and genomics in the study of complex diseases. The findings presented herein offer a baseline for further systematic reanalysis of all reported MTIs in human and other species.
Effects of sex, age, sampling time, and season on thyroid-stimulating hormone concentrations: A retrospective study.

Measuring thyroid-stimulating hormone (TSH) is essential for diagnosing and monitoring thyroid diseases. The aim of this study was to evaluate the effect of sex, age, sampling time and season on TSH in a large Chinese population and to determine which factor had the greatest impact on TSH measurement results.
Data were obtained from the laboratory information system from September 1, 2013 to August 31, 2016. A total of 80150 TSH measurements of outpatients were enrolled in this study. TSH was measured using a Siemens ADVIA Centaur XP automatic chemiluminescence immunoassay analyzer. Linear regression models were used to assess the association between log-transformed TSH concentrations and sex, age, sampling time and season.
The serum TSH concentrations in women were significantly higher than in men. In all subjects, serum TSH concentrations increased by 0.005 μIU/mL for each year of age. TSH concentrations showed circannual variation during the 3 consecutive years of data collection and decreased during the summer while increased during the winter. The serum TSH concentrations decreased from 7 a.m. to 1 p.m. while increased from 1 p.m. to 4 p.m. The same trend was observed in TSH concentrations for sampling time stratified by sex. Linear regression revealed that sampling time might be the major factor affecting serum TSH concentrations.
Sex, age, season, and sampling time significantly affected serum TSH concentrations. Age-related alteration in serum TSH concentrations was observed in this study. Sampling time was the major factor affecting serum TSH concentrations.

Mental Illness and Prejudices in Psychiatric Professionals. Data from the Social Stigma Questionnaire for Psychiatric Professionals: A Multicentre Study.

The prejudices about mental illness and the related social stigma are still present in the population. People suffer from both the disease and the marginalization behaviors implemented by the “so-called healthy” towards them and their relatives. Even psychiatric professionals can get sick and suffer for the same reason. The authors of this multicentric study have focused their attention on the presence or absence of groups of psychiatric pathologie

s among the “insiders”. The most frequent pathologies encountered were the mood and anxiety disorders, in a percentage similar to that of the general population. To continue the research on the stigma begun in a previous study, the authors asked themselves if there could be prejudices and/or stigma among psychiatric professionals towards sick colleagues, how they relate in the workplace and how they react to the behavior of colleagues. The stigma questionnaire has been used on psychiatric professionals, and 130 Italian colleagues were tested in the provinces of Avellino, Brindisi and Trento. The data were compared with those of the research on the stigma “Thinking of Psychiatric Disorders as” Normal “Illness” (Tavormina et al. 2016) and it emerged that among the attending professionals there are no statistically significant behaviors of marginalization, exclusion or stigma against sick colleagues, even if there is a certain discomfort in working together. Above all, it emerged that 80% of the interviewees, who have had work experience with sick colleagues, have replied that the latter can treat those who are also sick of their own disease, thus showing esteem and confidence in their work, in analogy with the Jungian thesis of the “wounded Healer” in the myth of the centaur Chiron.

Difficulties in cerebrospinal fluid βhCG interpretation in a patient with an infundibular lesion.

A variety of neoplastic, inflammatory and congenital conditions can cause pituitary stalk thickening. Differentiating between these causes is important as targeted treatment may be offered. Diagnostic work-up consists of a thorough history, examination, biochemical analysis and imaging. We present the case of a 33-year-old male who presented with diabetes insipidus and had pituitary stalk thickening on magnetic resonance imaging. Further investigations revealed an elevated CSF βhCG, which raised the possibility of an intracranial germ cell tumor. However, when repeated on four different assays, the βhCG levels were discordant. On serial imaging, the pituitary stalk thickening reduced slightly, which would be unexpected for a germ cell tumor. This case raises the difficulties interpreting CSF βhCG, as not all immunoassays for βhCG have been validated for use in CSF. The Roche Diagnostics Elecsys and Siemens Centaur assays have been validated for CSF βhCG, and so we advocate using one of these methods. If unavailable or serum/CSF results are ambiguous, serial MRI is appropriate, with pituitary stalk biopsy considered if the stalk measures>>6.5 mm or other imaging abnormalities are present.
Most adult patients with central diabetes insipidus have imaging abnormalities on a pituitary MRI. The most common abnormalities are loss of the posterior pituitary bright spot and pituitary stalk thickening, both of which are non-specific.Causes of pituitary stalk thickening include neoplastic, inflammatory, infective and congenital lesions.Investigation of pituitary stalk thickening should encompass the many possible causes and include biochemical analyses as well as imaging of the chest, abdomen and pelvis. Further investigations should be guided by the clinical context, but may include testicular ultrasound, CSF analysis and pituitary stalk biopsy.Germ cell tumors involving the pituitary stalk may be suspected on clinical grounds, but in the absence of a tissue diagnosis (biopsy) confirmation may be difficult and relies on biochemical assessment of blood and possibly CSF as well as serial MRI imaging.CSF βhCG levels should be analyzed on an instrument validated for use in CSF or on multiple instruments, and the pitfalls of testing this marker (false negative in some germ cell tumors, false positives in other conditions, lack of internationally agreed reference ranges for diagnosing germ cell tumors) should be considered when interpreting the results.
Multi-centre evaluation of recent troponin assays for the diagnosis of NSTEMI.

We aimed to compare the use of nine different cardiac troponin (cTn) assays (2 cTnT and 7 cTnI) for the diagnosis of NSTEMI in a single multi-centre population.
One hundred and fifty-eight patients were included (mean age 60 years, SD 17 years), including 23 patients (14%) with NSTEMI.
The analytical comparison highlighted a large heterogeneity of cTn assays, as reflected by percentages of patients with detectable cTn, correlation coefficients, Passing-Bablok comparisons and concordance coefficients. Correlations within cTnI assays were good and correlation within cTnT assays was excellent. Diagnostic performances demonstrated that each cTn assay has specific threshold values. Furthermore, some assays (HS-cTnI and T, cTnI-Pathfast and cTnI-Centaur) indicated high sensitivity and negative predictive value using the limit of detection (LoD) diagnostic strategy. For the latter assays, a significant increase in specificity was found when using the 99th percentile or the H0-H3 strategies, in comparison to the LoD strategy. When applying the European Society of Cardiology H0-H3 algorithm, comparable diagnostic performances were obtained.
All 9 cTn assays indicated overall good diagnostic performances for the diagnosis of NSTEMI in emergency departments when the recommended algorithm based on the variation of cTn value between two measurements at admission and 3 h later was used.