Elecsys Assay Research Articles

Comparative Evaluation of Multimarker Algorithms for Early-Stage HCC Detection in Multicenter Prospective Studies

Background and aimsWe compared the clinical performance of the novel GAAD (gender [biological sex], age, alpha-fetoprotein [AFP], des-gamma carboxy-prothrombin [DCP]) and GALAD (gender [biological sex], age, AFP, Lens culinaris agglutinin-reactive AFP [AFP-L3], DCP) algorithms to deduce the clinical utility of AFP-L3 for detecting early-stage hepatocellular carcinoma (HCC) from chronic liver disease (CLD). MethodsAn algorithm development study (STOP-HCC-ARP) and clinical validation study (STOP-HCC-MCE) were conducted, recruiting adult participants with HCC (confirmed by radiology or pathology) or CLD in an international, multicenter, case-control design. Serum biomarkers were measured using Elecsys assays (GAAD and GALAD [Cobas]) or μTASWAKO assays (GALAD [μTASWAKO]) while blinded to case/control status. ResultsIn STOP-HCC-ARP (algorithm development cohort), 1006 patients (297 HCC [41.4% early-stage [(Barcelona Clinic Liver Cancer [(BCLC)] 0/A)] and 709 CLD) were included. Area under the curve [AUCs] for discriminating between early-stage HCC vs CLD were 91.4%, 91.4%, and 90.8% for GAAD (Cobas), GALAD (Cobas), and GALAD (μTASWAKO), respectively. The clinical validation cohort of STOP-HCC-MCE comprised 1142 patients, (366 HCC cases (48% early-stage), 468 specificity samples and 302 CLD); AUCs for GAAD (Cobas), GALAD (Cobas), and GALAD (μTASWAKO) for discriminating between early-stage HCC vs CLD were 91.4%, 91.5%, and 91.0%, respectively; AUCs were 94.7-95.0% for all-stage HCC.The GAAD and GALAD algorithms demonstrated similar good performance regardless of disease etiology, presence of cirrhosis, geographical region, and within pan-tumor specificity panels (p<0.001). ConclusionsGAAD (Cobas) demonstrated good clinical performance, similar to GALAD (Cobas and μTASWAKO) algorithms, in differentiating HCC and CLD controls, across all disease stages, etiologies and regions; therefore, AFP-L3 may have a negligible role in GALAD for HCC surveillance. Impact and implicationsTo improve the detection of early-stage hepatocellular carcinoma (HCC) from benign chronic liver disease (CLD), algorithms combining demographic characteristics and serum biomarkers, such as GAAD and GALAD, have been developed. GAAD combines gender (biological sex), age, alpha-fetoprotein (AFP), des-gamma carboxy-prothrombin (DCP); GALAD combines the same characteristics and biomarkers as GAAD with the addition of Lens culinaris agglutinin-reactive AFP (AFP-L3). Changing disease etiologies and treatment paradigms have raised questions regarding the utility of AFP-L3 in HCC surveillance. Our work demonstrates that the GAAD (Cobas) algorithm demonstrated good clinical performance and was as sensitive and specific as the GALAD (Cobas) and GALAD (μTASWAKO) algorithms in differentiating HCC and CLD controls, across all disease stages, etiologies, and geographical regions; therefore, AFP-L3 may have a negligible role in HCC detection. Our study provides supporting evidence that in participants with CLD undergoing guideline-directed HCC surveillance, the GAAD (Cobas) algorithm may be used as an effective method for the detection of HCC, potentially resulting in improved patient outcomes.

Development of an enzyme-linked immunosorbent assay for newborns dried blood spot thyroglobulin.

Thyroglobulin (Tg) is a biomarker of iodine status. Newborn Tg is a more sensitive marker than neonatal TSH in detecting variations in iodine intake. This study aims to validate a Tg enzyme-linked immunosorbent assay (ELISA) for Tg determination on dried blood spots (DBS) in newborns. This study also set out to assess the stability of Tg and the influence of newborns' hematocrit on Tg determination. A commercially available ELISA Tg assay was adapted for use on DBS. DBS-Tg in cord blood were measured in 209 newborns delivered from healthy euthyroid pregnant women. Sensitivity, linearity, repeatability, and intermediate fidelity were determined using the appropriate standards and quality control materials. The limit of detection (LoD) of the DBS-Tg assay was 2.4 µg/L, and the limit of quantification (LoQ) was 5.8 µg/L. Repeatability and intermediate fidelity were 7.7-8.3% and 11.0-11.2%, respectively. The median cord plasma Tg and DBS-Tg values in newborns were not significantly different, 30.2 (21.3-44.4) µg/L and 31.6 (19.3-48.7) µg/L (p=0.48) with the ELISA respectively, and 76.5 (40.0-101.5) µg/L with the Elecsys assay with an R=0.88. DBS-Tg concentrations decrease with increasing hematocrit values (p<0.05). DBS-Tg values were stable at a concentration of 25 µg/L for 12 months at -20ºC and 4ºC. This DBS-Tg assay demonstrated good analytical performances over a wide range of Tg concentrations, suggesting it is well suited to detecting variations in Tg concentrations. Studies comparing populations with different prevalence of anemia should consider the effect of hematocrit on DBS-Tg determination. The availability of a DBS-Tg assay for newborns makes it possible to integrate iodine status monitoring with newborn screening for inherited metabolic diseases.

Evaluation of the biomarker-based ABC-AF-bleeding risk score and clinically based bleeding scores in 31,605 patients with atrial fibrillation treated with oral anticoagulation

Abstract Background International guidelines recommend a systematic evaluation of bleeding risk in patients with atrial fibrillation (AF) to guide oral anticoagulation. However, it remains challenging to accurately predict bleeding risk. The biomarker-based ABC-AF-bleeding risk score to predict bleeding in anticoagulated patients with AF has shown promise. Purpose To evaluate the performance of the biomarker-based ABC-AF-bleeding risk score and compare its performance with other bleeding risk scores in 31,605 patients randomized to direct oral anticoagulant or warfarin using individual patient data from three randomized clinical trials. Methods The COMBINE AF biomarker data set contains individual patient data from three pivotal randomized trials (ARISTOTLE, ENGAGE AF-TIMI 48, and RE-LY) comparing apixaban, edoxaban or dabigatran with warfarin, in patients with AF at increased risk of stroke. The ABC-AF-bleeding biomarkers were analyzed in plasma samples collected at baseline (hemoglobin, troponin T high-sensitivity, and GDF-15) using Roche Diagnostics Elecsys assays. The biomarker-based ABC-AF-bleeding risk score (Age, Biomarkers, Clinical history of prior bleeding) was calculated as previously published. The discrimination was assessed by Harrell’s c index and compared with three clinically based bleeding risk scores; HASBLED, ORBIT, and DOAC. Results During a median follow-up time of 2.0 years, a total of 1,572 ISTH major bleeding events occurred (incidence rate per 100 person-years of 2.79) including 593 gastrointestinal (1.04) and 270 intracranial (0.47) bleeding events. The biomarker-based ABC-AF-bleeding score was well calibrated for major bleeding in the total material (Figure). The c indices for major bleeding were 0.68 (95% confidence interval 0.67-0.70), for gastrointestinal bleeding 0.70 (0.68-0.72), and for intracranial bleeding 0.66 (0.63-0.69). The biomarker-based ABC-AF-bleeding risk score provided superior discrimination compared with the clinically based risk scores in the full cohort (Table). The ABC-AF-bleeding risk score also provided superior discrimination for major bleeding in clinically relevant subgroups based on age, sex, body mass index, coronary artery disease, diabetes, heart failure, kidney function, and irrespective of DOAC or VKA use. Conclusions In patients with AF treated with different types of OAC the biomarker-based ABC-AF-bleeding score provide better discrimination of the risk för major bleeding than risk scores based only on clinical factors. The results were consistent for different types of bleeding and across multiple subgroups. There was good calibration when comparing predicted vs observed rate of major bleeding. These findings support the utility of the biomarker-based ABC-AF-bleeding risk score for advancing precision medicine in patients with AF.Calibration of ABC-AF-bleeding scoreTable

B-093 Analytical performances of a novel fluorescent immunoassay of anti-Müllerian hormone and establishment of the reference intervals in Chinese children

Abstract Background Anti-Müllerian Hormone (AMH) plays a important role in children growth and the concentrations change with age as well as gender. This study aimed to evaluate the analytical performances of a novel AMH assay based on the cycle enhanced fluorescence immunoassay (CEFIA) and establish the pediatric reference intervals of AMH Methods The experiments on imprecision, sensitivity, linearity, linear range and comparison were carried out to evaluate the analytical performances. Furthermore, the concentrations of serum AMH in 238 females and 346 males aged 0-18 years were measured by the Pylon AMH assays and the reference ranges for ages group were calculated using robust methods. Results The repeatability and the within-laboratory imprecision CVs of the assay were 3.7% and 6.4% at at 2.25 ng/mL, and 4.6% and 6.4% at 15.49 ng/mL, respectively. The sensitivity of the assay (LoB =0.05 ng/mL, LoD= 0.1 ng/mL and LoQ= 0.3 ng/mL) was verified. The AMH Pylon assays showed good linearity within the detection range (between 0.1 and 24 ng/ml) and can report up to 480 ng/mL with 20x pre-dilution of samples. The AMH concentrations of serum samples measured by the Pylon assays correlated to those measured by the Elecsys assays. In the males under 18 years old, the AMH levels were high at birth (0-1 month: median 95.10 ng/mL) and continued to increase to a peak between 7 months to one year old (median 158.80 ng/mL) before they started to decrease with age to the lowest level between 15 and 18 years old (median 6.31 ng/mL). On the other side, the serum AMH concentrations in females were low at birth (0-1 month: median 0.20 ng/mL) and increased with age (15-18 years old: median 3.03 ng/mL). The reference intervals were provided for each gender and age groups,respectively. Conclusions The Pylon AMH assays showed good analytical performances, and the AMH reference intervals in chinese children determined may provide a basis for the use in clinical diagnosis and treatment of related diseases.

A-018 Diagnostic Performance of the Novel Beckman-Coulter NT-proBNP-assay in the Early Diagnosis of Acute Heart Failure

Abstract Background The diagnostic performance of the novel Beckman Coulter N-terminal pro-B-type natriuretic peptide (NT-proBNP) assay in the early diagnosis of acute heart failure (AHF) is unknown. Methods This major unmet clinical need was addressed in a secondary analysis using frozen plasma samples obtained in a prospective diagnostic study, enrolling patients presenting with acute dyspnea to the emergency department (ED). Two independent cardiologists/internists centrally adjudicated the final diagnosis using all individual patient's information. NT-proBNP-Beckman Coulter plasma concentrations were measured blinded and directly compared to NT-proBNP-Elecsys concentrations. Agreement analysis was performed by Bland Altman plot. The primary endpoints were the diagnostic accuracy of both assays using the Area-under-the-Receiver-Operating-Curve and the comparison of the performance for diagnosing AHF using the validated NT-proBNP-Elecsys clinical decision values (&amp;lt;300ng/L for rule-out, age-adjusted &amp;gt;450/900/1800ng/L for rule-in). The secondary endpoint included the application of the recently suggested NT-proBNP-Elecsys clinical decision values for obese patients. Results 1400 patients (46% 3women, median age 76 years, BMI 25.9m2/kg, LVEF 53%) had both NT-proBNP measurements on presentation to the ED. Of those 744 (53%) had an adjudicated diagnosis of AHF. The agreement analysis showed overall higher concentrations for the NT-proBNP-Beckman assay. The diagnostic accuracy of both assays was excellent (AUC: 0.915 vs 0.922; P = 0.006, respectively). In the clinical application less patients were ruled-out using the Beckman assay compared to the Elecsys assay (18.7% vs 26.3%) with comparable sensitivities (98.9% vs 98.5%). Regarding rule-in NT-proBNP-Elecsys had a significantly higher specificity (78.8% vs 70.9%) and positive predictive value (83.1% vs 78.7%; both P&amp;lt;0.001; Figure 1). Similar findings were obtained in recently suggested cutoffs for obese patients. Conclusions In comparison to established NT-proBNP-Elecsys cutoffs, a derivation of Beckman-specific cutoffs is needed to implement NT-proBNP-Beckman Coulter clinical decision values providing a higher rule-out proportion and an optimal specificity for diagnosing AHF.

O-193 Age-related normograms of AMH in women with polycystic ovary syndrome using three different assays

Abstract Study question To develop an age-specific percentile distribution of anti-Müllerian hormone (AMH) in patients with polycystic ovary syndrome (PCOS) measured by three different assays. Summary answer Our age-related normograms may help to interpret AMH levels in PCOS patients and facilitate the use of AMH as a diagnostic tool across age ranges. What is known already In the last years, AMH assessment has gained widespread use in the clinical settings of several conditions. However, several challenges still exist to adopt the AMH as a marker of polycystic ovary morphology (PCOM), as included in the recently updated international guideline. Although different evaluations of age- and assay-specific reference ranges have been published in the last years, these studies have mainly been conducted in normo-ovulatory or infertile women and little is known about the higher range of AMH levels, especially in women with PCOS. Study design, size, duration Retrospective single-center cross-sectional study, including 2,725 women with PCOS who consulted the Reproductive Endocrinology and Infertility Clinic of the Erasmus University Medical Center, Rotterdam, The Netherlands. Participants/materials, setting, methods A total of 2,725 women aged 20 to 40 years with PCOS were included. PCOS was diagnosed according to the Rotterdam Criteria. Serum AMH levels were measured using the following AMH assays: (1) Gen II AMH ELISA, 2) picoAMH assay, and 3) Elecsys AMH plus assay. Age-specific centile curves were constructed using the LMS method. The correlations between AMH with clinical, endocrine, and ultrasound features were also evaluated. Main results and the role of chance To our knowledge, this is the first study with real-world data reporting AMH age-specific percentile nomograms in a large population of PCOS women using three different assays. The 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles were calculated according to a population/based approach per age (years) for the Gen II, the picoAMH, and the Elecsys assays. We also considered the age-percentile values of AMH in PCOS patients for the Gen II, the picoAMH and the Elecsys assays according to the cut-offs previously proposed in literature for each specific assay. Interestingly, in our population, a high percentage of women with polycystic ovarian morphology (PCOM) showed AMH levels lower than the cut-offs proposed. Serum AMH levels were significantly higher in patients with phenotype A compared to all other phenotypes for all three assays. For all three assays, we found a statistically significant positive correlation between AMH levels and LH, LH/FSH ratio, testosterone, androstenedione, FAI, mean follicular number, and mean ovarian volume. In contrast, AMH levels were negatively correlated with BMI in all groups. Limitations, reasons for caution This is a retrospective cross-sectional study. Longitudinal studies with a large cohort of women that could be followed for many years are needed to validate our nomogram. Wider implications of the findings AMH threshold levels can be influenced by several variables, making it difficult to identify a general cut-off to diagnose PCOM. Further research should overcome the concept of a single cut-off value. The results of the present study may help clinicians interpret AMH levels in PCOS patients across age ranges. Trial registration number In this retrospective cross-sectional study, 2,725 women who consulted the Reproductive Endocrinology and Infertility Clinic of the Erasmus University Medical Center, Rotterdam, The Netherlands, were included. The Medical Ethical Review Board of the Erasmus University Medical Center Rotterdam approved retrospective studies within this patient population, which includes women with ovulatory dysfunction (MEC-2020-0534).

Head-to-head comparison of four plasma neurofilament light chain (NfL) immunoassays

BackgroundNeurofilament Light Chain (NfL) is an emerging blood biomarker of neuro-axonal injury and neurodegeneration with the potential to be used in the clinical management of various neurological conditions. Various NfL immunoassays are in development on high-throughput automated systems, but little information is available related to the comparability between assays. In this study, we performed a head-to-head comparison of four NfL immunoassays using plasma samples from individuals with various neurological conditions. MethodsEDTA plasma samples in which NfL was ordered clinically were stratified according to diagnosis. NfL concentrations (pg/mL) in plasma were obtained using the Quanterix Simoa®, the Roche Elecsys, the Siemens Healthineers Atellica®IM, and the Fujirebio Lumipulse® NfL assays. Passing-Bablok regression analyses were performed to assess the correlation and bias between methods. Additionally, the distribution of NfL concentrations for each assay was assessed in three disease groups: amyotrophic lateral sclerosis (ALS) upon initial diagnosis, ALS treated, and multiple sclerosis (MS). ResultsThe R2 between assays were all ≥ 0.95, however, significant proportional bias was observed between some assays. In particular, the Roche Elecsys assay NfL concentrations were significantly lower (∼85 %) when compared against the other three assays. The four assays were comparable with regards to the percentage of patients that were identified as having an elevated NfL result in the various clinical groups: ALS initial diagnoses (83–94 %), ALS untreated (93–100 %), and MS (8–18 %). ConclusionsThis is the first study describing a head-to-head comparison of four automated NfL immunoassays. We demonstrate that there is a strong correlation between assays but a lack of standardization which is evident by the bias observed between some of the evaluated methods. These analytical differences will be important to consider when using NfL as a biomarker of neurodegeneration.

Abstract PO2-11-06: Anti-Müllerian hormone in Young women with breast CAncer to predict permanent loss of ovarian function after chemotherapy and anti-HER2 therapy (AMYCA): a biomarker analysis of the BETH and KAITLIN trials

Abstract Background: The ability to predict and identify ovarian function loss accurately after anticancer treatment is important for appropriate oncofertility counseling and to aid in therapy decision making for young women with early breast cancer (eBC). Anti-Müllerian hormone (AMH) has been proposed as both a pre- and post-treatment predictor of subsequent permanent loss of ovarian function. The present biomarker analysis conducted within two randomized controlled trials (RCTs) in a large and well-characterized patient population with HER2+ eBC receiving homogeneous treatment aimed to assess AMH use, alone and in combination with other hormonal biomarkers, for predicting loss of ovarian function at 36 months from randomization, i.e. approximately 2 years after end of therapy. Methods: BETH (NCT00625898) and KAITLIN (NCT01966471) were RCTs investigating adjuvant chemotherapy (CT) plus anti-HER2 therapy in high-risk HER2+ eBC patients. For the purpose of the present analysis, only samples of patients receiving currently adopted treatments were used, i.e. cohort 1A (6 cycles of docetaxel/carboplatin+trastuzumab (T)) and cohort 2A (3 cycles of docetaxel plus T followed by 3 cycles of anthracycline- and cyclophosphamide-based CT) of BETH trial, and arm 1 (3-4 cycles of anthracycline- and cyclophosphamide-based CT followed by 3-4 cycles of taxane plus T plus pertuzumab (P)) of KAITLIN trial. Women selected for this analysis were ≤45 years with known premenopausal status, available serum samples at baseline (pre-treatment) and/or end of therapy and 36 months (± 6 months) from randomization (i.e. min of 2 samples in all cases). Selected samples were centrally tested measuring AMH, follicle stimulating hormone (FSH) and estradiol (E2) using Roche Elecsys assays. Permanent ovarian loss was defined as FSH &amp;gt;25 IU/L and E2 &amp;lt; 110 pmol/L at 36 months. Results: Of 194 included patients, 62 were from BETH and 132 from KAITLIN. 139 (71.6%) received both taxane and anthracycline- and cyclophosphamide-based CT and 55 (28.4%) taxane only. Pertuzumab was used in addition to trastuzumab in 132 (68.0%) patients. AMH values declined from baseline median 8.44 pmol/L to undetectable levels in many women at end of therapy (median 0.08 pmol/L), with partial recovery at 36 months (median 0.14 pmol/L). Ovarian loss at 3 years was observed in 56 women with AMH available at baseline (29.5%) and in 52 women with AMH available at end of therapy (29.7%). For prediction of ovarian loss, in ROC analysis, AMH measured at baseline showed AUC 0.784 (internally validated using bootstrap: 0.783). While age influenced risk of ovarian loss, addition to AMH only slightly improved AUC to 0.800 (internal validation: 0.795) while addition of baseline FSH and E2 did not improve prediction. AMH measured at the end of therapy showed AUC 0.741 (internal validation: 0.742), which increased slightly to 0.785(internal validation: 0.781) with addition of age but without improved prediction with the addition of FSH and E2. The combination of AMH at baseline and end of therapy increased prediction slightly to 0.808 (internal validation 0.806) and with addition of age added to 0.820 (internal validation: 0.806). Conclusions: These results support the use of pretreatment measurement of AMH in predicting loss of ovarian function in women withHER2+ eBC aged ≤45 receiving CT and anti-HER2 therapy. Measurement of AMH at end of treatment was comparably valuable to pretreatment and added slightly to the value of pretreatment sampling. Inclusion of ovarian function assessment by measuring AMH before commencing treatment can inform subsequent risk of ovarian function loss with value for fertility preservation counselling and treatment decisions. Further validation is required in larger cohorts. Citation Format: Matteo Lambertini, Deirdre Allegranza, Ruediger Laubender, Nadia Harbeck, Sandra Swain, Charles Geyer, Dennis Slamon, Gabriella Bobba, Chiara Lambertini, Sanne Lysbet De Haas, Eleonora Restuccia, Ines Vaz Luis, David Cameron, Ian Krop, Eric Winer, Richard Anderson. Anti-Müllerian hormone in Young women with breast CAncer to predict permanent loss of ovarian function after chemotherapy and anti-HER2 therapy (AMYCA): a biomarker analysis of the BETH and KAITLIN trials [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-11-06.

High Frequency of Prior Severe Acute Respiratory Syndrome Coronavirus 2 Infection by Sensitive Nucleocapsid Assays.

Prior infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is typically measured by nucleocapsid serology assays. In this study, we show that the Simoa serology assay and T-cell intracellular cytokine staining assay are more sensitive than the clinical Elecsys assay for detection of nucleocapsid-specific immune responses. These data suggest that the prevalence of prior SARS-CoV-2 infection in the population may be higher than currently appreciated.

Age-related Curves of AMH Using the Gen II, the picoAMH, and the Elecsys Assays in Women With Polycystic Ovary Syndrome.

Several challenges still exist to adopt the anti-müllerian hormone (AMH) as a marker of polycystic ovary morphology, as included in the recently updated international guideline. Although different evaluations of age- and assay-specific reference ranges have been published in the past few years, these studies have mainly been conducted in normo-ovulatory or infertile women. To develop an age-specific percentile distribution of AMH in patients with polycystic ovary syndrome (PCOS) measured by 3 different assays. Retrospective cross-sectional study. A total of 2725 women aged 20 to 40 years with PCOS diagnosis were included. Serum AMH measurement by the Gen II (Beckman Coulter), the picoAMH (Ansh Labs), and the Elecsys (Roche) assays. Age-specific percentile curves for all the assays and correlations between AMH, clinical, hormonal, and ultrasound characteristics. Age-related nomograms for the 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles of AMH were calculated using the Lambda-Mu-Sigma method for all the assays. AMH levels were significantly different between PCOS phenotypes. AMH levels were positively correlated to LH, LH/FSH ratio, testosterone, androstenedione, free androgen index, mean follicular number, and mean ovarian volume. To our knowledge, this is the first study reporting age-specific percentile nomograms of serum AMH levels measured by the Gen II, the picoAMH, and the Elecsys assays in a large population of women with PCOS. These findings may help to interpret AMH levels in patients with PCOS and facilitate the use of AMH as a diagnostic tool across age ranges.

Dietary Consumption With Vitamin D Status Among Pregnant Women: A Descriptive-Analytic Study.

This study aimed to investigate the relationship between vitamin D status and diet between pregnant and non-pregnant women who attended a Maternity Teaching Hospital (MTH) in Sulaymaniyah, Iraq. A descriptive-analytic (cross-sectional) study was conducted at the MTH in Sulaymaniyah, Iraq. Data was collectedfrom January to October 2022, including demographics, obstetric information, and dietary data. Vitamin D levels were measured using the Roche Elecsys assay (Roche Diagnostics, Indianapolis, Indiana, United States). The non-pregnant group consisted of women who were not pregnant at the time of this study, and the pregnant group had women with second trimester pregnancy at the time of enrollment. The study revealed a significant prevalence of vitamin D deficiency among pregnant women. In the study, pregnant participants (56.0% aged 30-39) and non-pregnant participants (54.3% aged 20-29) had similar ages (p>0.05). Both groups mostly had overweight individuals, with pregnant participants having a slightly higher mean body mass index (BMI).While vitamin D deficiency was more prevalent among pregnant women, the differences were not statistically significant. Notably, higher dairy intake was positively associated with higher vitamin D levels. Urban residency was common in both groups. Dietary habits were mostly similar, except for tea consumption (p<0.05), with non-tea drinkers having higher vitamin D levels. However, dietary patterns did not strongly correlate with vitamin D levels in the non-pregnant group. This study reveals a significant prevalence of vitamin D deficiency among pregnant women, although the differences between pregnant and non-pregnant groups were not statistically significant. The positive association between higher dairy intake and increased vitamin D levels underscores the potential impact of dietary choices on vitamin D status during pregnancy.However, the study also suggests that dietary patterns alone may not strongly correlate with vitamin D levels in non-pregnant women. Overall, this highlights the importance of addressing vitamin D deficiency in pregnant women and underscores the need for personalized dietary guidance, taking into account individual preferences and habits to promote better maternal health.

ESC 0/1h-algorithm using the updated, biotin-resistant high-sensitivity cardiac troponin T assay

Abstract Background For rapid and safe triage of patients with suspected non-ST-elevation myocardial infarction (NSTEMI), the European Society of Cardiology (ESC) recommends the use of a 0/1h-algorithm based on high-sensitivity cardiac troponin (hs-cTn) T or I. Recently, multiple widely used immuno-assays including hs-cTnT have been reported to interfere with high biotin concentrations, potentially leading to false-negative results. To address this major concern, an updated, biotin-resistant hs-cTnT assays has been developed by the manufacturer to replace its previous version. Purpose We aimed to assess and compare the clinical performance of the updated, biotin-resistant hs-cTnT Elecsys assay when using the original ESC hs-cTnT 0/1h-algorithm. Methods In a prospective international diagnostic study enrolling patients presenting with suspected NSTEMI to the emergency department (ED), hs-cTnT was serially measured at ED presentation and after one hour with the original, biotin-sensitive (hs-cTnT-original) and the updated, biotin-resistant hs-cTnT (hs-cTnT-updated) assay. Patients presenting with STEMI were excluded. The final diagnosis was centrally adjudicated by two independent cardiologists using all available data including coronary angiography, echocardiography, follow-up data, and serial measurements of hs-cTn. We assessed the overall efficacy, rule-out safety and rule-in accuracy of the ESC hs-cTnT 0/1h-algorithm when using hs-cTnT-updated and compared it with the use of hs-cTnT-original. Results NSTEMI was the final diagnosis in 162 of 865 (19%) patients. The ESC 0/1h-algorithm using hs-cTnT-updated triaged 58% of patients towards "rule-out", 21% towards "rule-in", and 21% towards "observe" compared to 56%, 21% and 23% using hs-cTnT-original, respectively (Figure 1, p=ns). Only 6 patients were reclassified using hs-cTnT-updated. Safety of rule-out was very high using hs-cTnT-updated with a negative predictive value for NSTEMI of 100% (95% confidence interval (CI), 99.2-100%) and a sensitivity of 100% (95%CI, 97.7-100%) and was highly comparable to hs-cTnT-original (NPV 100% [95%CI 99.2-100], sensitivity 100% [95%CI, 97.7-100%], all p-values for comparison not significant). Of note, no NSTEMI-patient was missed by the ESC 0/1h-algorithm neither using hs-cTnT-updated nor original. Similarly, accuracy of rule-in was very high (positive predictive value 73.7% [95%CI, 66.8-79.6%], specificity 93.3% [95%CI, 91.2-94.9%]) and highly comparable to hs-cTnT-original (PPV 73.9% [95%CI 67.1-79.7%], specificity 93.2% [95%CI, 91.1-94.8%], all p-values for comparison not significant). Conclusions The safety and efficacy of the ESC 0/1h-algorithm using the novel updated, biotin-resistant hs-cTnT-assay is excellent and similar to the use of the original assay without the need to adjust the cutoffs to the new assay.Figure 1

Prognostic implications of angiopoietin-2 in heart failure and the influence of empagliflozin: the EMPEROR program

Abstract Background Heart failure (HF) development and progression is associated with endothelial dysfunction, oxidative stress, and inflammation. The mechanisms involved in endothelial repair in HF are not fully understood. Emerging evidence suggests that angiopoietin-2 (Angpt2), a vascular destabilizing factor, may be related to outcome in HF. Aim To assess the association between Angpt2 and clinical outcomes in a pooled analysis of the EMPEROR-Reduced and EMPEROR-Preserved trials, and to evaluate if the response to empagliflozin therapy in HF is modulated by Angpt2 levels. Methods and results Angpt2 levels (ng/ml) were measured in serum samples from 1131 EMPEROR study participants by using Roche Cobas Elecsys assay, within biomarker research agreement between Boehringer Ingelheim and Roche Diagnostics International Ltd, at baseline, week 12 and week 52. Patients were divided into tertiles of baseline Angpt2 levels (&amp;lt;2.58 ng/mL; ≥2.58 ng/mL &amp;lt;4.71 ng/mL and ≥4.71 ng/mL). Patients in the highest tertile were more frequently white people, had a higher prevalence of New York Heart Association class III-IV symptoms, HF hospitalization within 12 months, obesity, diabetes, atrial fibrillation, elevated natriuretic peptides, worse renal function, and lower prevalence of coronary disease, compared to the lowest tertile (p&amp;lt;0.05 for all). Higher tertile at baseline was associated with increased risk for adverse HF and kidney events (Table 1). Empagliflozin treatment was associated with reduction of the serum Angpt2 versus placebo at week 12 (adjusted gMean 0.872 [0.828-0.917], p&amp;lt;0.0001) but not at week 52 (adjusted gMean ratio 0.946, [0.879-1.019], p=0.145). Empagliflozin significantly reduced the risk of hospitalization for HF and cardiovascular death particularly for patients with highest baseline Angpt2 levels (lowest tertile HR 1.21 [0.63-2.31]; middle tertile HR 0.65 [0.37-1.16]; highest tertile HR 0.64 [0.42-0.97], P-trend=0.139). Conclusion Higher Angpt2 levels at baseline were associated with more advanced HF and worse prognosis. Treatment with empagliflozin was associated with reduction of Angpt2 level at week 12. The benefit of empagliflozin on major HF events was consistent across baseline Angpt2 levels.Table 1

Abstract 11936: Cardiorenal Prognostic Significance of IGFBP-7 Concentrations in Chronic Heart Failure: Findings From EMPEROR-Pooled

Introduction: Insulin-like growth factor binding protein-7 (IGFBP-7) is a biomarker of tissue senescence with a role in heart failure (HF) pathophysiology. We examined the association of IGFBP-7 with risk of HF hospitalization or cardiovascular (CV) death and progression of renal disease in the EMPEROR-Reduced and EMPEROR-Preserved Trials. Methods: IGFBP-7 was measured in serum samples in the placebo and empaglifozin arms at baseline (N= 561, 564), 12 weeks (N=558, 557) and 52 weeks (N=355, 358). IGFBP-7 was measured using Roche Cobas Elecsys assay within the Biomarker Research Agreement of Boehringer Ingelheim, the sponsor of the EMPEROR trials and Roche Diagnostics International Ltd. Association between IGFBP-7 and risk of HF hospitalization or CV death, estimated glomerular filtration rate (eGFR) slope, and renal composite outcome of sustained eGFR reduction ≥40% or end-stage renal disease were evaluated using multivariable modeling. Results: Study participants with IGFBP-7 levels in the third tertile had a higher risk clinical profile compared to those with lower values. Empagliflozin was not meaningfully associated with change in IGFBP7 at 12 or 52 weeks. In Cox proportional hazards models adjusted for clinical variables, N-terminal pro-B type natriuretic peptide and high-sensitivity cardiac troponin T, baseline IGFBP-7 values above the second tertile predicted a higher risk of HF hospitalization or CV death (HR: 2.00 95% CI 1.28-3.10, p=0.002), higher rate of eGFR decline (β estimate: -2.45, 95% CI: -3.40 - -1.50, p for trend =0.005) and higher risk of renal composite endpoint (HR: 4.66, 95% CI: 1.61-13.53, p=0.005). Empagliflozin reduced risk for CV death/HF hospitalization irrespective of baseline IGFBP-7 (p-trend across IGFBP-7 tertiles=0.26). Concentrations of IGFBP-7 were moderately correlated with other prognostic HF biomarkers of tissue remodeling including fatty acid binding protein-3, growth differentiation factor-15, and angiopoietin-2. Conclusions: IGBP-7 was correlated with worse clinical presentation and associated with adverse cardiovascular outcomes even in models adjusted for conventional biomarkers. Empagliflozin did not significantly affect IGFBP-7 levels over time.

B-009 Accuracy Validation of Elecsys HBsAg II Quant Assay to Resolve Equivocal Qualitative HBsAg Results

Abstract Background There are reports of false qualitative HBsAg results because of several causes, such as samples with low HBsAg concentrations that may produce false positives. The main aims of this study are to validate the analytical accuracy and operational cutoff value of the Elecsys HBsAg II Quant assay. The secondary goal is to assess the role of the Elecsys assay in resolving equivocal quali-tative HBsAg results compared to those of the qualitative HBsAg assay in the medical laboratory. Methods The limit of blank (LoB), limit of detection (LOD), limit of quantification (LoQ), and linearity were first estimated to validate the analytical accuracy of the Elecsys HBsAg II Quant assay. To validate the linearity of the assay according to CLSI EP06-A, five expected diluted as-sayed samples, including 0.01 (dilution ratio of minimum to maximum value = 4:0), 11.90 (3:1), 23.70 (2:2), 35.50 (1:3), and 47.30 IU/mL (0:4), were prepared within the concentration of the WHO 3rd IS (47.3 IU/mL) and measured for five replicates at each level. A total of 449 serum samples showing initial equivocal results (1–50 index) were evaluated by El-ecsys HBsAg II Quant and ADVIA Centaur HBsAg II assays. Results The LoQ of the assay was determined to be 0.050 IU/mL, as provided by the manufacturer. The Kappa agreement between the two assays was almost perfect at 0.9669 despite the seven dis-cordant results. The ROC curve analysis of this assay showed an AUC of 0.965 (P &amp;lt; 0.001), with a specificity of 100% and sensitivity of 24.15% at the new COI value of 5.42. Those HBsAg samples with index values &amp;lt;5.42 need to be confirmed with an approved method or via additional HBV marker assays without further duplicate tests. The Kappa agreement between the two assays was almost perfect at 0.9669 despite the seven discordant results (three by ADVIA Centaur HBsAg II Negative and Elecsys HBsAg II Quant Positive; four by ADVIA Centaur HBsAg II Positive and Elecsys HBsAg II Quant Negative). The concordance rate and accuracy of the ADVIA Centaur HBsAg II as-say relative to the Elecsys HBsAg II Quant assay from the confirmed results were 98.44% and 98.55%, respectively, when the HBsAg seroprevalence of 5.3% from the Western Pa-cific region, including South Korea, was applied. Conclusion We confirm that the Elecsys HBsAg II Quant assay is a very accurate and sensitive for HBV infec-tion and recommend it as an alternative confirmatory HBsAg assay for resolving equivocal qualitative HBsAg results.

A-021 Comparing the Time Between the 1st and 2nd Troponin in Male and Female Patients in Singapore and Calgary, Alberta: Evidence of Extended Pre-preanalytical Time in Females with Low ACS Risk

Abstract Background At the 2022 AACC national meeting, in our assessment of reference change values (RCV) in troponins ordered in Calgary and Singapore, we postulated that there were gender differences in troponin-ordering between the two cities. Methods Singapore Changi Hospital ED patients [July 2018–July 2020] and Calgary patients [December 2017–December 2021] had hsTnT measured with the Roche Elecsys assay on multiple, local Cobas e801’s. The first two troponins of each patient were selected if they were ordered within 12 h. The troponin pairs were grouped by city, patient sex and whether the troponin pairs fulfilled the criteria of low likelihood of Acute Coronary Syndrome (ACS) according to city specific guidelines. Results The figure compares the average time difference between the first and second troponin test of females and males stratified by the initial troponin value. The paired t-test conducted shows that in Singapore there was no significant difference in the time for females and males to receive a second troponin test while in Calgary the time for females to receive a second troponin test was significantly longer (P &amp;lt; 0.0001) than males. Conclusion The significant difference between Calgary females and males in average time between the first and second troponin tests supports the idea that there may be gender specific differences in troponin ordering timing and patterns. 62%–68% of all laboratory errors originate from pre-pre-analytical processes of which timing is a factor. The well documented atypical presentation of myocardial infarction in females may contribute to the delayed second test in women. This timing difference may be a contributor to the RCV variance observed in our previous study which identified gender differences in the assessment of RCV in troponins ordered in Calgary and Singapore.

Evaluating the sensitivity and specificity of dried blood spots for serological testing of HIV, syphilis, hepatitis B and C Elecsys assays on the Roche Cobas system

This study was performed to validate a dried blood spot (DBS) method for the serological screening of HIV, syphilis, hepatitis B and C. It included 250 paired DBS and serum samples and 116 unpaired DBS samples from 366 unique patients from two laboratories between 8 October and 2 November 2021. As determined by original test request, these were tested using a DBS method for HIV Ag/Ab (n=216), anti-treponemal Ab (n=166), hepatitis B sAg (n=100), and hepatitis C Ab (n=100) Elecsys assays on the Roche Cobas automated platform. Using the manufacturer's (serum) cut-off for reactivity ('positivity'), the sensitivity and specificity of DBS testing compared with serum were: for HIV Ag/Ab 100% and 100%, for anti-treponemal Ab 68.3% and 100%, for hepatitis B sAg 95.9% and 100%, and for hepatitis C Ab 84.0% and 100%, respectively. Adjusting the assay cut-off using receiver operator curve analysis increased sensitivity of DBS testing for anti-treponemal Ab to 90.0%, hepatitis B sAg to 97.9% and hepatitis C Ab to 94.0% whilst maintaining specificity of 98.8%, 100% and 100%, respectively. With optimisation of assay cut-off, DBS can perform comparably with serum for serological testing for HIV, syphilis, hepatitis B and C and may be a valuable tool in increasing access to testing in New Zealand.

Low BAU/ml values with 4 of 5 SARS CoV-2 spike-specific monoclonal antibodies in the Roche Elecsys antibody assay

BackgroundThe Abbott SARS-CoV-2 IgG Quant II assay and the Roche Elecsys double antigen sandwich (DAgS) immunoassay measure SARS-CoV-2 receptor binding domain (RBD)-specific antibodies in serum samples in different ways. The IgG Quant II assay uses an antigen in combination with a secondary antibody and the DAgS assay uses two antigens. The aim of the study was to investigate whether the assays give comparable results with monoclonal antibodies. Material and MethodsThe immunoassays were tested with the RBD-specific human monoclonal antibodies (mAbs) casirivimab. imdevimab, CR3022, etesevimab and sotrovimab. The mAbs were tested at various concentrations in µg/ml, alone or in combination and the relative light units (RLU) and binding antibody units (BAU)/ml were determined. ResultsWith 1 µg/ml of casirivimab, imdevimab, CR3022 and etesevimab the Abbott IgG II Quant assay yielded between 65 and 158 BAU/ml and the Elecsys assay < 0.4 – 7.1 BAU/ml. In the DAgS assay, the addition of a second and a third mAb increased the BAU/ml values synergistically. With increasing concentrations of the mAb combinations in µg/ml the Abbott IgG Quant II assay showed proportionate and the Elecsys DAgS assay disproportionate increases in BAU/ml. With 1 µg/ml sotrovimab the Abbott assay gave 39 and the Elecsys assay 136 BAU/ml. The DAgS assay showed a high dose hook effect in the µg/ml range. ConclusionsThe secondary antibody-based and the DAgS-based SARS CoV-2 antibody assays gave very different results with 4 of 5 mAbs. This suggests that the two assays measure different binding characteristics. The ability of antibodies to cross-link multiple antigen-antibody complexes may contribute to the measurement signal in the DAgS assay.

O-067 Does the measurement of different AMH isoforms in poor responder patients improve the prediction of ovarian response?

Abstract Study question Does the measurement of AMH isoforms in low ovarian reserve patients improve the prediction of the number of oocytes after ovarian stimulation (OS)? Summary answer AMH assays measuring a broader range of AMH isoforms combined with antral follicle count (AFC) improve the prediction of oocytes collected after OS. What is known already Granulosa cells secrete AMH as a non-active prohormone (proAMH). After cleavage, it forms a complex (AMHN,C) which activates the receptor (AMHR2). Circulating AMH is a mixture of isoforms (proAMH, AMHN,C and other sub-fragments) after proteolysis, targeted by the monoclonal antibodies included in the AMH assays commonly used in clinical practice, potentially affecting the quantification of the hormone. Novel AMH assays include antibodies directed towards a broader range of the molecule. They may provide more accurate and reliable results, especially important in poor responders, as results may involve clinical decisions on whether or not to proceed with OS. Study design, size, duration Prospective observational study measuring AMH isoforms using five different AMH assays, including 72 women with low ovarian reserve performing OS for IVF/ICSI at a tertiary referral fertility center, from February 2019 to December 2021. Low ovarian reserve was defined as AMH serum levels &amp;lt;1.1ng/ml (Elecsys, Roche), following Bologna criteria. All patients performed OS for IVF/ICSI with antagonist protocol. Participants/materials, setting, methods On day 2/3 of cycle, prior to initiating the OS, AFC, serum FSH, LH, estradiol, progesterone and AMH levels were measured using Elecsys assay (Roche). Extra serum samples were frozen at -20C for subsequent analysis, using four different AMH assays (AnshLabs, Texas): AL-196 (PCOCheck ELISA), AL-124 (PicoAMH ELISA), AL-105 (US-AMH ELISA) and AL-133 (Total Mature-AMH ELISA). Ethical approval was obtained (Research Ethics Committee-REFA033c) and informed consent was signed by all participants. Main results and the role of chance Patient characteristics were [Median(IQR)]: age:39(36-42)years, BMI:28.51(26.1-30.1) Kg/m2, AFC:5.5(4-7), FSH:8.23(6.4-12.5) mIU/mL, LH 6.54(4.51-8.91) mIU/mL, Estradiol: 41.18(28.47-56.44)pg/mL, AMH-Elecsys: 0.64(0.29-0.81)ng/mL, AL-196:0.64(0.39-0.99)ng/mL, AL-124:0.79(0.49-1.24ng/mL, AL-105: 0.89(0.57-1.39)ng/mL, AL-133:1.06(0.63-1.59)ng/mL. Stimulation outcomes were: follicle number on the day of trigger (Fdot):5(3-7), cumulus-oocyte-complexes (COC’s):3(2-4.5) and metaphase II oocytes (MII):3(1-4). Spearman correlation was performed between AMH assays, AFC and OS outcomes. Elecsys revealed a good correlation with the other AMH assays (rs = 0.60-0.63,p&amp;lt;0.001), however, it was higher among ELISA assays (rs = 0.954-0.993,p&amp;lt;0.001). All AMH assays showed a significant positive correlation with AFC, Fdot, COC’s and MII. However, AL-196 showed the highest correlation (rs = 0.524, rs = 0.615, rs = 0.594, rs = 0.595, respectively;p&amp;lt;0.001). Different models combining one AMH assay plus AFC were created to predict COC’s and MII: AFC+AL-196 revealed the best prediction (Adjusted R2=0.474[p &amp;lt; 0.001] and 0.485[p &amp;lt; 0.001], respectively) when compared to the same AMH assay alone. AUROC analysis was performed to investigate which model predicted better &amp;lt; =3COC’s after OS. Although all models demonstrated fair values, AUROC was better for AFC+AL-196 model (AUROC:0.796), yet no significant differences were seen when compared to AUROC for AFC+AMH-Elecsys (p = 0.39). AFC and AMH were good predictors for COC’s collected [RR(95%CI):1.49(1.11-2.04),p&amp;lt;0.01; RR(95%CI):1.26(1.13-1.49),p&amp;lt;0.001, respectively). AFC+AMH-Elecsys predicted COC’s better than AFC alone (R2=0.47 vs 0.29, respectively;Performance-Score:42.56% vs 13.21%, respectively). AFC+AL-196 had the highest performance (R2=0.599;Performance-Score:90.12%). Limitations, reasons for caution Although clinical assessment was performed in the same centre following the same methodology, inter-observer variability for AFC is a limitation. Besides, fresh AMH serum samples were analysed using Elecsys assay, whereas frozen serum samples were shipped to Ansh Lab (Texas) for batched analysis. Wider implications of the findings For patients with serum AMH&amp;lt;1.1ng/mL, a wide range of oocytes might be expected after OS. Novel AMH assays, targeting a wider broad of the molecule, together with AFC, can be used for these patients to obtain a better prediction for clinical outcomes and anticipate very poor response. Trial registration number Not applicable

P-604 Inhibin B in Low Ovarian Reserve Patients: Correlation With Ovarian Reserve Markers and Oocyte Yield

Abstract Study question Is there a correlation between Inhibin B (InhB) serum levels and oocyte yield after ovarian stimulation (OS) in women with low ovarian reserve? Summary answer InhB presents a positive relationship with oocyte yield during OS in women with AMH&amp;lt;1.1ng/mL. What is known already InhB is produced by granulosa cells in the ovary with the goal of suppressing FSH production. Assay and intercycle variability have been the main limitations affecting specificity and reproducibility of InhB as a marker of ovarian reserve or oocyte yield after OS. This fact is attributed to low specific antibodies for the molecule in previous assays, exhibiting cross-reactivity with other glycoproteins in the transforming growth factor beta family. High specific ELISA assay,measuring bioavailable InhB (bio-InhB), may provide more accurate results, specially important in poor responders, as results may involve clinical decisions on whether or not to proceed with OS. Study design, size, duration Prospective observational study measuring bio-InhB in 72 women with low ovarian reserve, performing OS for IVF/ICSI, at a tertiary referral fertility center, from February 2019 to December 2021. Low ovarian reserve was defined as AMH serum levels &amp;lt;1.1ng/ml (Elecsys, Roche), following Bologna criteria. All patients performed OS for IVF/ICSI in a GnRH-antagonist protocol. Participants/materials, setting, methods On day 2/3 of cycle, before starting OS, AFC, FSH, LH, estradiol, progesterone and AMH (Elecsys, Roche) were measured. Extra serum samples were frozen at -20C for subsequent bio-InhB analysis (AnshLabs, Texas). Ethical approval was obtained (Research Ethics Committee-REFA033c) and informed consent was signed for all participants. Main results and the role of chance Patient characteristics were [Median(IQR)]: age: 39(36-42)years, BMI: 28.51(26.1-30.1) Kg/m2, AFC: 5.5(4-7), FSH:8.23(6.4-12.5) mIU/mL, LH: 6.54(4.51-8.91) mIU/mL, Estradiol: 41.18(28.47-56.44) pg/mL, AMH: 0.64(0.29-0.81)ng/mL, InhB: 62.69(33.78-97.92) pg/mL. Stimulation outcomes were: follicle number on day of trigger (Fdot): 5(3-7), cumulus-oocyte-complexes (COC’s): 3(2-4.5) andmetaphase II oocytes (MII): 3(1-4). Inh-B showed significant positive correlation (Spearman correlation) with AMH (rs = 0.35, p = 0.003), although was better with AFC (rs = 0.43, p &amp;lt; 0.001). Moreover, Inh-B serum levels presented positive association with oocyte yield: Fdot (rs = 0.41, p &amp;lt; 0.001), COC’s (rs = 0.36, p = 0.002) and MII (rs = 0.37, p = 0.002). AUROC analysis was performed to investigate which model predicted better a bad outcome (defined as &amp;lt; =3COC’s after OS) in low ovarian reserve women. No significant benefit was observed when Inh-B was added to AMH+AFC model (AUROC AMH+AFC: 0.757; AUROC AMH+AFC+Inh-B: 0.759, p = 0.843). Limitations, reasons for caution Although clinical assessment was performed in the same centre following the same methodology, inter-observer variability for AFC is a limitation. Besides, fresh AMH serum samples were analysed using Elecsys assay, yet frozen serum samples were shipped to Ansh Lab (Texas) for batched Inh-B analysis. Wider implications of the findings Bio-InhB is correlated to oocyte yield during OS. Although no additional benefit for prediction in women with AMH&amp;lt;1.1ng/mL was observed when added to other currently used markers, future research should explore the utility of bio-inhB on other outcomes associated to ovarian reserve, as embryo quality and ploidy. Trial registration number Not applicable