OBJECTIVES:Use of polyclonal antibodies (pAbs) in immunoassays has limitations related to inter-batch variation and supply chain stability which may affect assay reproducibility, scalability, and sustainability. The Elecsys® Anti-TPO II assay, where the pAb of the Elecsys Anti-TPO assay has been replaced with two monoclonal antibodies, aims to address these factors. We evaluated analytical and clinical performance for Elecsys Anti-TPO II using Cobas® e 601 and e 801 analyzers. METHODS:Repeatability, intermediate precision, and reproducibility were assessed over 5 days at three sites, within/between multiple reagent lots and analyzers. Method comparisons were performed against Elecsys Anti-TPO and three other immunoassays, using 218 serum samples covering the measuring range. The clinical cutoff was derived from 85 patients with confirmed Hashimoto thyroiditis (HT); reference intervals determined using samples from 230 healthy euthyroid individuals. Clinical performance was evaluated in 608 patients with confirmed HT, Graves disease, non-autoimmune thyroid diseases, or non-thyroid autoimmune diseases. RESULTS:Elecsys Anti-TPO II demonstrated high precision (standard deviations for repeatability, intermediate precision, and reproducibility <1.6 IU/mL for measurements ≤30 IU/mL; coefficients of variation <7 % for measurements >30 IU/mL) and improved semi-quantitative agreement (94.0-97.7 %) with comparator assays, vs. Elecsys Anti-TPO (88.5-90.8 %). The 95th percentile of the reference range cohort was <8 IU/mL; specificity in this cohort was 97.4 % (cutoff of ≥20 IU/mL). Clinical sensitivity for HT was 90.5 %; clinical specificity in disease control groups was 90.7 %. CONCLUSIONS:Elecsys Anti-TPO II offers robust analytical and clinical performance, supporting its utility in diagnosing auto-immune thyroid diseases in routine clinical practice.

BACKGROUND:Measurement of cardiac troponin (cTn) using high-sensitivity assays is recommended for the diagnosis of myocardial infarction. We determined sex-specific and uniform 99th percentile upper reference limits (URLs) using the new Elecsys® Troponin T high-sensitivity Gen 6 assay in a global, healthy reference range cohort. METHODS:Lithium-heparin plasma and serum samples were prospectively collected from apparently healthy individuals aged ≥20 years across 34 global sites in the United States, Europe, China, and Japan. cTnT was measured using the Troponin T high-sensitivity Gen 6 assay on the Cobas® e 801 analyzer. Exclusion criteria were defined according to the 2022 IFCC guidance. Uniform and sex-specific 99th percentile URLs and nonparametric 95% CIs were determined in plasma and serum separately and combined. RESULTS:The final study population comprised 4147 participants (52.5% female) with a median (25th-75th percentiles) age of 48.0 (33.0-59.0) years; 45.8%, 47.9%, 5.2%, and 1.1% were White, Asian, Black, and other/unknown, respectively. For sample matrices combined (n = 8294), 81.0% and 99.2% of cTnT values were above the limit of detection in females and males, respectively. Sex-specific 99th percentile URLs (95% CI) were 18 (16-23) ng/L for females and 32 (28-35) ng/L for males; the uniform 99th percentile URL was 27 (24-31) ng/L. URLs were comparable in plasma and serum samples. CONCLUSIONS:This study determined sex-specific and uniform 99th percentile URLs for the Troponin T high-sensitivity Gen 6 assay that were comparable irrespective of the matrix used in a large, global, healthy reference population.

Supplementary Figure S1; Supplementary Table S1.

Abstract Background For pregnant women with suspected preeclampsia, the soluble fms-like tyrosine-kinase 1 (sFlt-1)/placental growth factor (PlGF) ratio is a biomarker to aid diagnosis. We performed method comparisons between Elecsys® and Kryptor sFlt-1 and PlGF immunoassays and assessed the diagnostic performance for preeclampsia. Methods Serum samples from a case-control study involving 113 pregnant women with preeclampsia/elevated liver enzymes and low platelet count (HELLP) and 270 controls were analyzed. sFlt-1 and PlGF were measured using Roche Elecsys® and BRAHMS Kryptor sFlt-1/PlGF immunoassays. The sFlt-1/PlGF ratios were calculated, and Passing-Bablok regression/Bland-Altman plots were performed. Gestation-specific cut-offs, ≤33 and ≥85/≥110, were assessed. Results Mean (±2 standard deviation [SD]) differences between the Elecsys® and Kryptor values were: sFlt-1, 173.13 pg/mL (6237.66, −5891.40); PlGF, −102.71 pg/mL (186.06, −391.48); and sFlt-1/PlGF, 151.74 (1085.11, −781.63). The Elecsys® and Kryptor immunoassays showed high correlation: Pearson’s correlation coefficients were 0.913 (sFlt-1) and 0.945 (PlGF). Slopes were 1.06 (sFlt-1) and 0.79 (PlGF), resulting in ~20% lower values for Kryptor PlGF. Sensitivities and specificities using the sFlt-1/PlGF ≥85 cut-off for early-onset preeclampsia (20 + 0 to 33 + 6 weeks) were 88.1%/100.0% (Elecsys®) and 90.5%/96.2% (Kryptor), respectively, and using the ≥110 cut-off for late-onset preeclampsia (≥34 + 0 weeks) were 51.3%/96.5% (Elecsys®) and 78.9%/90.1% (Kryptor), respectively. Using Elecsys® and Kryptor sFlt-1/PlGF, 0% and 3.8% of women, respectively, were falsely ruled-in for early-onset, and 3.5% and 9.9%, respectively, for late-onset preeclampsia. Conclusions Despite high correlation between the Elecsys® and Kryptor immunoassays, we observed significant differences between sFlt-1/PlGF and PlGF results. Therefore, sFlt-1/PlGF cut-offs validated for Elecsys® immunoassays are not transferable to Kryptor immunoassays.

ed from N Engl J Med 2016;374:13–22 Preeclampsia, a heterogeneous, multisystem disorder defined by the new onset of hypertension and proteinuria after 20 weeks of gestation, affects 2% to 5% of pregnancies worldwide. The ratio of soluble fms-like tyrosine kinase 1 (sFlt-1) to placental growth factor (PlGF) is elevated in pregnant women before the clinical onset of preeclampsia, but its predictive value in women with suspected preeclampsia is unclear.

OBJECTIVE: To assess the association of a serum soluble fms-like tyrosine kinase 1-to-placental growth factor (sFlt-1-to-PlGF) ratio of greater than 38 with time to delivery and preterm birth. METHODS: Secondary analysis of an observational cohort study that included women 18 years of age or older from 24 to 36 6/7 weeks of gestation at their first study visit with suspected (not confirmed) preeclampsia. Participants were recruited from December 2010 to January 2014 at 30 sites in 14 countries. A total of 1,041 women were included in time-to-delivery analysis and 848 in preterm birth analysis. RESULTS: Women with an sFlt-1-to-PlGF ratio greater than 38 (n=250) had a 2.9-fold greater likelihood of imminent delivery (ie, delivery on the day of the test) (Cox regression hazard ratio 2.9; P<.001) and shorter remaining time to delivery (median 17 [interquartile range 10–26] compared with 51 [interquartile range 30–75] days, respectively; Weibull regression factor 0.62; P<.001) than women with an sFlt-1-to-PlGF ratio of 38 or less, whether or not they developed preeclampsia. For women who did not (n=842) and did develop preeclampsia (n=199), significant correlations were seen between an sFlt-1-to-PlGF ratio greater than 38 and preterm birth (r=0.44 and r=0.46; both P<.001). Among women who did not develop preeclampsia, those who underwent iatrogenic preterm delivery had higher median sFlt-1-to-PlGF ratios at their first visit (35.3, interquartile range 6.8–104.0) than those who did not (8.4, interquartile range 3.4–30.6) or who delivered at term (4.3, interquartile range 2.4–10.9). CONCLUSIONS: In women undergoing evaluation for suspected preeclampsia, a serum sFlt-1-to-PlGF ratio greater than 38 is associated with a shorter remaining pregnancy duration and a higher risk of preterm delivery.

BACKGROUND:The ratio of soluble fms-like tyrosine kinase 1 (sFlt-1) to placental growth factor (PlGF) is elevated in pregnant women before the clinical onset of preeclampsia, but its predictive value in women with suspected preeclampsia is unclear.METHODS:We performed a prospective, multicenter, observational study to derive and validate a ratio of serum sFlt-1 to PlGF that would be predictive of the absence or presence of preeclampsia in the short term in women with singleton pregnancies in whom preeclampsia was suspected (24 weeks 0 days to 36 weeks 6 days of gestation). Primary objectives were to assess whether low sFlt-1:PlGF ratios (at or below a derived cutoff) predict the absence of preeclampsia within 1 week after the first visit and whether high ratios (above the cutoff) predict the presence of preeclampsia within 4 weeks.RESULTS:In the development cohort (500 women), we identified an sFlt-1:PlGF ratio cutoff of 38 as having important predictive value. In a subsequent validation study among an additional 550 women, an sFlt-1:PlGF ratio of 38 or lower had a negative predictive value (i.e., no preeclampsia in the subsequent week) of 99.3% (95% confidence interval [CI], 97.9 to 99.9), with 80.0% sensitivity (95% CI, 51.9 to 95.7) and 78.3% specificity (95% CI, 74.6 to 81.7). The positive predictive value of an sFlt-1:PlGF ratio above 38 for a diagnosis of preeclampsia within 4 weeks was 36.7% (95% CI, 28.4 to 45.7), with 66.2% sensitivity (95% CI, 54.0 to 77.0) and 83.1% specificity (95% CI, 79.4 to 86.3).CONCLUSIONS:An sFlt-1:PlGF ratio of 38 or lower can be used to predict the short-term absence of preeclampsia in women in whom the syndrome is suspected clinically. (Funded by Roche Diagnostics.).

Clinical signs and symptoms of preeclampsia are known to be poorly predictive of who will develop the condition, prompting the investigation of angiogenic biomarkers as potential diagnostic and predictive aids. The Elecsys® immunoassay soluble fms-like tyrosine kinase (sFlt-1)/placental growth factor (PlGF) ratio is Conformité Européenne-In Vitro Diagnostics approved as a diagnostic aid for preeclampsia, and as an aid in the short-term prediction of preeclampsia (rule out and rule in) in pregnant women with suspected preeclampsia in conjunction with other diagnostic and clinical information. In the Prediction of Short-Term Outcome in Pregnant Women with Suspected Preeclampsia Study (PROGNOSIS), a cut-off value of 38 was derived and validated to rule out preeclampsia and HELLP (hemolysis, elevated liver enzymes and low platelet count) syndrome within one week (Zeisler et al. N Engl J Med 2016;374:13–22). However, the ability of the sFlt-1/PlGF ratio to rule out preeclampsia up to four weeks in women with suspected disease has not been determined. We aimed to establish the negative predictive values (NPVs) applying the Elecsys® immunoassay sFlt-1/PlGF ratio cut-off value of 38 to rule out preeclampsia within two to four weeks after testing in women with suspected preeclampsia. PROGNOSIS was a prospective, observational, multicenter study, which validated the sFlt-1/PlGF ratio cut-off value of 38 to reliably rule out preeclampsia within one week in women who had clinical signs and symptoms of the syndrome (gestational age 24w + 0d–36w + 6d). We performed a post-hoc analysis of the data from the validation cohort of 550 participants to determine the NPV of this ratio cut-off value to rule out preeclampsia within two, three and four weeks after testing. A total of 550 participants from the PROGNOSIS validation cohort were included in this analysis (median age 31 years; median pre-pregnancy body mass index 26.2 kg/m2; median systolic blood pressure 128.0 mmHg; median gestation week 31w + 3d; 79 (14%) were current smokers; 418 (76%) were white/Caucasian). Of these, 98 (18%) developed preeclampsia/HELLP syndrome at some point during their pregnancy: 15 (3%) within one week; 41 (7%) within two weeks; 60 (11%) within three weeks; and 71 (13%) within four weeks. The NPV to rule out preeclampsia in women with sFlt-1/PlGF values of 38 and below within two, three and four weeks of testing was 97.9% (95% confidence interval [CI]: 96.0–99.0), 95.7% (95% CI: 93.3–97.5), and 94.3% (95% CI: 91.7–96.3), respectively (Table). This post-hoc analysis of PROGNOSIS shows that sFlt-1/PlGF ratios of 38 and below could rule out preeclampsia for up to four weeks after testing with high NPV in women with suspicion of the syndrome.Download : Download high-res image (215KB)Download : Download full-size image

BACKGROUND Recent single-center and retrospective studies suggest that acute myocardial infarction (AMI) could be immediately excluded without serial sampling in patients with initial high-sensitivity cardiac troponin T (hs-cTnT) levels below the limit of detection (LoD) of the assay and no electrocardiogram (ECG) ischemia. OBJECTIVE We aimed to determine the external validity of those findings in a multicenter study at 12 sites in nine countries. METHODS TRAPID-AMI was a prospective diagnostic cohort study including patients with suspected cardiac chest pain within 6 hours of peak symptoms. Blood drawn on arrival was centrally tested for hs-cTnT (Roche; 99th percentile = 14 ng/L, LoD = 5 ng/L). All patients underwent serial troponin sampling over 4-14 hours. The primary outcome, prevalent AMI, was adjudicated based on sensitive troponin I (Siemens Ultra) levels. Major adverse cardiac events (MACE) including AMI, death, or rehospitalization for acute coronary syndrome with coronary revascularization were determined after 30 days. RESULTS We included 1,282 patients, of whom 213 (16.6%) had AMI and 231 (18.0%) developed MACE. Of 560 (43.7%) patients with initial hs-cTnT levels below the LoD, four (0.7%) had AMI. In total, 471 (36.7%) patients had both initial hs-cTnT levels below the LoD and no ECG ischemia. These patients had a 0.4% (n = 2) probability of AMI, giving 99.1% (95% confidence interval [CI] = 96.7% to 99.9%) sensitivity and 99.6% (95% CI = 98.5% to 100.0%) negative predictive value. The incidence of MACE in this group was 1.3% (95% CI = 0.5% to 2.8%). CONCLUSIONS In the absence of ECG ischemia, the detection of very low concentrations of hs-cTnT at admission seems to allow rapid, safe exclusion of AMI in one-third of patients without serial sampling. This could be used alongside careful clinical assessment to help reduce unnecessary hospital admissions.

Objectives To evaluate the impact of age- and gender-specific cut-offs for high-sensitivity cardiac troponin T (hs-cTnT) compared to the general 99th percentile hs-cTnT cut-off on diagnosis and prognosis of acute myocardial infarction (AMI). Methods 1282 unselected patients presenting to the emergency department with suspected AMI were enrolled as part of the TRAPID-AMI study. In the present sub-analysis, reclassification of AMI diagnosis was performed by comparing the general hs-cTnT cut-off of 14 ng/L to previously proposed age- and gender-dependent hs-cTnT 99th percentile cut-offs (28 ng/L for ≥65 years, 9 ng/L for female and 15.5 ng/L for male patients). Patients were further clinically adjudicated into acute coronary syndrome (ACS) and non-ACS. Results For patients ≥65 years, application of age-specified cut-offs resulted in a decrease of AMI from 29.8% to 18.3% in the entire cohort (n = 557) and 54.7% to 40.9% in the ACS subcohort (n = 225). Using gender-specific cut-offs, AMI-rate increased from 16.6% to 22.6% (entire cohort, n = 477) and 62.6% to 71.7% (ACS subcohort, n = 99) in women, whereas in men, rates decreased from 23.1% to 21.1% (entire cohort, n = 805) and 48.8% to 45.9% (ACS, n = 281), respectively. Age-specified cut-offs significantly reclassified patients for outcomes of 1-month and 3-month mortality in the entire and ACS cohort (14.2% net reclassification improvement, p < 0.001, respectively). Contrary, no significant differences in outcomes could be found using gender-specific cut-offs. Conclusions While influence of gender-specific hs-cTnT cut-offs on diagnostic and prognostic reclassification was only modest in patients with suspected AMI, age-specific cut-offs showed a significant impact and may be considered for further validation.

Impact Of Markedly Elevated Initial High -Sensitivity Cardiac Troponin T On Prediction Of Acute Myocardial Infarction In Chest Pain Patients And Additional Value Of Kinetic Changes : Results From The Trapid-AMI Study

The TRAPID-AMI study was a multicenter trial evaluating the high sensitivity cardiac troponin T (hs-cTnT) assay in a rapid “rule-out” acute myocardial infarction (AMI) strategy in the Emergency Department (ED). We evaluated a modified HEART score (HS) to identify a low-risk group that involves

Objective: We aimed to evaluate the impact of age- and gender-specific cut-offs in comparison to the general 99th percentile cut-off for diagnosis and prognosis of acute myocardial infarction (AMI). Methods: 1282 unselected patients presenting with suspected AMI and recent (<6h) onset of chest pain to the emergency department were enrolled as part of the TRAPID-AMI study and 359 patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) qualified for further subanalysis. Patients were classified using age- and gender-dependent hs-TnT 99th percentile cut-off values previously described in literature (28 ng/L for ≥65y, 9 ng/L for female and 15.5 ng/L for male patients) in comparison to the general cut-off of 14 ng/L. Results: Table 1 displays changes regarding diagnostic reclassification and outcomes when comparing age-specific and general 99th percentile cut-off values in NSTE-ACS patients with age ≥65y (n=216). Significant reclassification concerning 1-month and 3-month mortality could be observed ...

Preeclampsia is defined as new onset of hypertension and proteinuria at gestational week 20 or after. However, use of these measures to predict preeclampsia before its clinical onset is unreliable, and evidence suggests that preeclampsia, eclampsia, or hemolysis, elevated liver enzymes and low platelet count (HELLP) syndrome may develop without hypertension or proteinuria being evident. Because of its unpredictability, varying clinical presentation and potential adverse outcomes, pregnant women with suspected preeclampsia require intensive monitoring or hospitalization. Beyond preeclampsia diagnosis, there is a high unmet medical need for more reliable predictive markers for preeclampsia to improve maternal and fetal outcomes and reduce unnecessary hospital admissions. An imbalance of circulating angiogenic and antiangiogenic factors, including raised soluble fms-like tyrosine kinase-1 (sFlt-1) and decreased placental growth factor (PlGF), has been found in women diagnosed with preeclampsia and before clinical onset of the disease. The PRediction of short-term Outcome in preGNant wOmen with Suspected preeclampsIa Study (PROGNOSIS) was designed to investigate the use of the sFlt-1/PlGF ratio in the short-term prediction of preeclampsia.

Results: Preeclampsia prevalence was 19.0%. Feasibility cohort: a sFlt-1/PlGF cut-off of 38 for all gestational ages was favorable. The validation cohort had 90% power to show: a negative predictive value (NPV) of> 96%, with the cut-off confirmed for 1-week rule-out of preeclampsia by a 95% CI of 97.9–99.9%; a positive predictive value (PPV) of> 25%, with the cut-off confirmed for 4-week rule-in by a 95% CI of 28.4–45.7%. In the full evaluable dataset (n= 1050), the sFlt-1/PlGF cut-off showed promising NPV, PPV, sensitivity and specificity (Table/Fig); primary objectives were met. Women with adverse outcomes (n= 2; cerebral hemorrhage plus preeclampsia; isolated cerebral thrombosis) had high sFLt-1/PlGF ratios. sFlt-1/PlGF was correlated with fetal adverse outcomes and a combined endpoint of maternal and/or fetal adverse outcomes and/or preeclampsia. Low and high sFlt-1/PlGF ratios were associated with absence and presence of combined outcomes, respectively.Predictive value of sFlt-1/PlGF cut-off of 38 (n= 1050)%(95% CI) 1-week rule-out of preeclampsia 4-week rule-in of preeclampsia NPV 99.1 (98.2–99.6) 94.9 (93.1–96.3) PPV 16.7 (12.3–21.9) 38.6 (32.6–45.0) Sensitivity 85.7 (72.8–94.1) 70.3 (61.9–77.8) Specificity 79.1 (76.5–81.6) 83.1 (80.5–85.5)

Abstract Background: Fecal occult blood testing (FOBT) is the recommended first line screening for the detection of colorectal cancer (CRC). To improve the detection of CRC we evaluated serum markers and combinations of serum markers as an alternative approach. Methods: Applying Lasso Regression, a specialized form of penalized logistic regression, we selected six markers for an evaluation in a collective of 857 patients including 301 CRC patients, 143 patients with adenoma, 266 healthy controls and 147 disease controls. For each marker and marker combination the performance was assessed. Results: We tested a total of 22 biomarkers for the detection of CRC from serum. Of these six markers were selected for a marker combination by Lasso Regression. Included were the well-known tumor markers CEA and CYFRA21-1 as well as novel markers or markers that are less routinely used for the detection of CRC: ferritin, osteopontin, anti-p53 and seprase. CEA showed the best sensitivity of all markers with 43.9 % at 95% specificity, followed by seprase (42.4%), CYFRA21-1 (35.5%), osteopontin (30.2%), ferritin (23.9%) and anti-p53 (20.0%). When these markers were combined a sensitivity of 72.3% was reached at a corresponding specificity of 95% and of 62.1% at 98% specificity. Focusing on more screening relevant stages, UICC stages 0-III, reduced the sensitivity slightly to 68.0% and 53.3%, respectively. In a sub-collective where matched stool samples were available (75 CRC cases and 234 controls) the sensitivity of the marker combination was comparable to fecal immunochemical testing (FIT) with 82.4% and 68.9% vs. 81.8% and 72.7% at 95% and 98% specificity, respectively. Conclusion: When six markers were combined to detect CRC from serum, the combination reached a performance that was comparable to FIT. This provides a novel tool for CRC screening to trigger a follow-up colonoscopy for a final diagnosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2738.

Abstract Purpose: Fecal occult blood testing is recommended as first-line screening to detect colorectal cancer (CRC). We evaluated markers and marker combinations in serum as an alternative to improve the detection of CRC. Experimental Design: Using penalized logistic regression, 6 markers were selected for evaluation in 1,027 samples (301 CRC patients, 143 patients with adenoma, 266 controls, 141 disease controls, and 176 patients with other cancer). The diagnostic performance of each marker and of marker combinations was assessed. Results: To detect CRC from serum samples, we tested 22 biomarkers. Six markers were selected for a marker combination, including the known tumor markers CEA (carcinoembryonic antigen) and CYFRA 21-1 as well as novel markers or markers that are less routinely used for the detection of CRC: ferritin, osteopontin (OPN), anti-p53, and seprase. CEA showed the best sensitivity at 95% specificity with 43.9%, followed by seprase (42.4%), CYFRA 21-1 (35.5%), OPN (30.2%), ferritin (23.9%), and anti-p53 (20.0%). A combination of these markers gave 69.6% sensitivity at 95% specificity and 58.7% at 98% specificity. Focusing on International Union against Cancer (UICC) stages 0–III reduced the sensitivity slightly to 68.0% and 53.3%, respectively. In a subcollective, with matched stool samples (75 CRC cases and 234 controls), the sensitivity of the marker combination was comparable with fecal immunochemical testing (FIT) with 82.4% and 68.9% versus 81.8% and 72.7% at 95% and 98% specificity, respectively. Conclusions: The performance of the serum marker combination is comparable with FIT. This provides a novel tool for CRC screening to trigger a follow-up colonoscopy for a final diagnosis. Clin Cancer Res; 16(24); 6111–21. ©2010 AACR.