Access Assay Research Articles

An automated commercial open access assay for detection of Mycoplasma genitalium macrolide resistance.

Azithromycin, a macrolide antibioticum, is the first-line treatment for Mycoplasma genitalium (MG), but resistant MG is an increasing problem. Macrolide resistance-mediated mutations (MRM) has been linked to point mutations in region V of the MG 23S rRNA gene. We have evaluated an open access analyzer (Panther Fusion, Hologic Inc) for detectability of MRM (mutations A2071G and A2072G) and MG wild type (WT) in clinical samples. Also, the agreement of the Panther Fusion assay results with a corresponding established In-house MRM-WT PCR (ABI 7500) was calculated. Left over material from 55 clinical samples positive for MG by the Aptima test (Hologic) based on transcription-mediated amplification (TMA), collected from January to February 2023 in Region Skåne, Sweden, was analyzed. Specific amplification curves were generated for positive controls of MG mutations (A2071G and A2072G) and WT by the Panther Fusion assay. The limit of detection (LOD) was 5.3 copies/mL for WT, 8.1 copies/mL for mutation A2071G, and 81 copies/mL for mutation A2072G. The overall concordance was 91% between the Panther Fusion and the In-house PCR (Kappa 0.621, 95% CI; 0.327-0.914) for detection of WT or MRM in MG-positive clinical samples. The Panther Fusion detected MRM in 20% (11/55) and WT in 62% (34/55) of the samples. The corresponding In-house PCR results were 25% (14/55) and 65% (36/55). In summary, the Panther Fusion assay demonstrated detection of low copy number of MRM and WT of MG. Among clinical samples substantial agreement between the Panther Fusion and In-house PCR results was observed. Integrating MG-analysis (TMA) and MRM-WT assay on the Panther platform could make MRM testing more readily available. However, the Panther Fusion had a lower success rate (82% vs 90%) for macrolide susceptibility testing, hence testing with a complementary method should be considered for samples where neither WT nor MRM MG are detectable.

Performance evaluation of the new Access HIV Ag/Ab combo assay on the DxI 9000 Access Immunoassay Analyzer

Fourth-generation HIV immunoassays have been developed to reduce the window period of detection during seroconversion period, allowing for the detection of early and established infections. The aim of this work was to evaluate a newly developed assay, Access HIV Ag/Ab combo on the novel high throughput DxI 9000 Access Immunoassay Analyzer (Beckman Coulter, Inc.). The assay allows for simultaneous qualitative detection and differentiation of HIV-1 p24 antigen and HIV-1/2 antibodies.Assay performance was compared to two gold standard assays, the Abbott Architect HIV Ag/Ab Combo and Roche Elecsys HIV Duo, and assessed in a multicenter study, using a wide panel of samples (n > 9000, clinical samples and viral lysates) representative of genetic diversity for both antibodies and antigens, early phases of infection, negative, and cross-reacting samples.The clinical sensitivity was 100 % for clinical samples as well as for viral lysates. Data on viral lysates and early detection on seroconversion panels showed a better result with the Access assay. Analytical sensitivity showed a limit of p24 detection determined around 0.2 IU/mL. The overall specificity was 99.91 %, and no interference was found using the potentially cross-reactive samples.In conclusion, the Access HIV Ag/Ab combo assay demonstrated its ability for accurate diagnosis of chronic as well as primary HIV infections on the DxI 9000 Analyzer, despite the high level of genetic diversity of these viruses.

Performance evaluation of the Access anti-HBc Total assay on the DxI 9000 Access Immunoassay Analyzer

This study evaluated the diagnostic and analytical performances of the Access anti-HBc Total assay on the DxI 9000 Access Immunoassay System (Beckman Coulter Inc.). The multicenter study involved both prospective and retrospective sample collection from non-selected blood donors, hospitalized patients, or presumed anti-HBc Total positive individuals. Fresh/previously-frozen samples were tested with the Access and comparator assays to determine concordance; discrepant samples were tested with a second CE-marked assay. Among the 5983 non-selected fresh blood donor samples deemed anti-HBc Total negative, clinical specificity of the Access assay was 99.58% (95%CI: 99.38–99.72%). Clinical specificity was 99.27% (97.37–99.80%) among 273 anti-HBc Total negative hospitalized patient samples. Clinical sensitivity on 450 anti-HBc Total positive samples was 99.78% (98.75–99.96%). Evaluation in seroconversion panels revealed an average 1.4-day earlier detection versus a comparator assay. The Access assay demonstrated excellent clinical and analytical performances comparable to existing CE-marked anti-HBc Total assays. NCT04904835.

Biomarker Analysis of Zanubrutinib and Tislelizumab Combination Therapy in Patients with Relapsed/Refractory B-Cell Malignancies

Background/Introduction: Diffuse large B-cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma world-wide. Although frontline therapies have yielded positive outcomes in most patients with DLBCL, about one-third of patients are refractory to or relapse after standard therapy (Sehn et al. J Clin Oncol 2005;23(22):5027-33). The antitumor efficacy of zanubrutinib and tislelizumab combination therapy has been demonstrated in patients with B-cell malignancies (Tam et al. Blood 2019;134:1594). Herein, we performed a comprehensive analysis to examine biomarkers associated with response or resistance to zanubrutinib and tislelizumab combination therapy in patients with B-cell malignancies. Methods: Biomarker analysis was performed in 24 patients with published response data determined by the investigator using Lugano 2014 criteria (Cheson et al. J Clin Oncol 2014;32(27):3059-68). Programmed death-ligand 1 (PD-L1) gene amplification was assessed in the baseline tumor of 11 patients with non-germinal center B-cell (GCB) subtype of DLBCL by fluorescence in situ hybridization (Empire Genomics). PD-L1 protein expression was examined in the baseline tumor (8 DLBCL) by immunohistochemistry (IHC) (Ventana PD-L1 [SP263] assay; Roche). DLBCL subtype and gene expression were examined in the baseline tumor (14 DLBCL) by HTG EdgeSeq DLBCL cell of origin assay (HTG Molecular Diagnostics). Gene mutation was examined in the baseline tumor (17 DLBCL) by DNA-seq (CGI NGS 220-Gene Panel assay; Cancer Genetic Inc.). PD-L1 and CD8 protein expression were examined in paired biopsy samples (1 DLBCL, 3 transformed follicular lymphoma [tFL], 1 follicular lymphoma [FL], 1 mantle cell lymphoma) before and 8 days after zanubrutinib treatment by IHC (Ventana SP263, CONFIRM CD8 SP57). Gene expression profiles were examined in paired biopsy samples (3 tFL, 1 FL, 1 chronic lymphocytic leukemia) by RNA-seq (RNA Access assay; Illumina). Results:PD-L1 gene alteration was observed in 2 of 11 patients with non-GCB DLBCL, including 1 with gene amplification and 1 with chromosome 9 polysomy. A higher overall response rate (ORR; 2/2 [100%] vs 3/9 [33.3%]) and complete response (CR) rate (2/2 [100%] vs 2/9 [22.2%]) was observed in patients with PD-L1 gene alteration than in patients without. Two of 8 [25%] evaluable patients with DLBCL harbored PD-L1+ tumor cells (defined using a PD-L1 protein expression cut-off ≥1%). A higher ORR (1/2 [50%] vs 2/6 [33%]) and CR rate (1/2 [50%] vs 1/6 [16.7%]) was observed in patients with PD-L1+ tumor cells than in those without. High mRNA levels of CD3D (P < 0.05), HLA-DRA (P < 0.07), and LAG3 (P < 0.05) were enriched in responders, suggesting an inflamed tumor microenvironment (TME). In contrast, non-responders harbored high mRNA levels of the NF-kB pathway-related gene REL (P < 0.05). High mRNA levels of REL were associated with an inferior clinical outcome to zanubrutinib and tislelizumab combination therapy (P < 0.05). Mutations in the tumor suppressor gene TP53 (5/10 [50%] vs 0/7 [0%]) were enriched in non-responders. Non-responders harbored higher frequency of mutations in genesinvolved in immune evasion (3/10 [30%] vs 1/7 [14.3%]), epigenetic modifications (2/10 [20%] vs 1/7 [14.3%]), and cell survival (2/10 [20%] vs 0/7 [0%]) than responders, suggesting that non-responders may have complex resistance mechanisms. Results from paired tumor biopsies from 5 patients before and after zanubrutinib treatment revealed that zanubrutinib treatment downregulated B-cell and MYC target-related gene sets and upregulated the NK cell-related gene set NK-2. Zanubrutinib treatment seemed to have no effect on the frequency of PD-L1+ cells and CD8+ T cells (using a CD8 expression cutoff of ≥1%) in the TME, although the sample size was too small to draw a definitive conclusion. Conclusion: Patients with PD-L1 gene amplification, PD-L1+ tumor cells, and high mRNA levels of CD3D, HLA-DRA, and LAG3 in baseline tumor tissue may be more responsive to zanubrutinib and tislelizumab combination therapy. A high mRNA level of REL or mutations in TP53 may contribute to resistance of zanubrutinib and tislelizumab combination therapy. Due to the limited number of samples, results must be interpreted with caution.

Multi-center evaluation of the highly sensitive Abbott ARCHITECT and Alinity thyroglobulin chemiluminescent microparticle immunoassay.

BackgroundThyroglobulin (Tg) is an essential part for the management of patients with differentiated thyroid carcinoma (DTC) after thyroidectomy. Highly sensitive Tg assays are now established in clinical practice as they facilitate follow‐up of DTC patients. In this study, we evaluated the recently launched highly sensitive Abbott Tg assay for Alinity and ARCHITECT.MethodsIn this three‐center study, Tg values of 447 routine patient samples, characterized for the presence of anti‐Tg, were measured with the ARCHITECT Tg assay and compared with the Roche Elecsys TgII assay. In addition, a subset of 154 samples was compared also with the Beckman Tg Access assay and another subset (n = 122) with Abbott Tg on the Alinity i analyzer.ResultsLoQ was verified to be less than or equal to 0.1 ng/ml confirming that the Tg assay on ARCHITECT and Alinity is highly sensitive. Correlation of ARCHITECT, Alinity, and Roche was excellent with a slope between 0.9 and 1.1 and a correlation coefficient >0.98. Correlation to Beckmann Tg was also very good, but the differences in absolute values were significant (slope: 1.477).ConclusionsThe Abbott Thyroglobulin assay, which is standardized to CRM‐457, demonstrated a high correlation to the Roche and Beckman Tg assays, though good agreement of absolute values was only observed between Abbott and Roche. Strength of correlation and slope were not affected by the presence of anti‐Tg indicating that all assays included in the study have a similar susceptibility to anti‐Tg.

222 Prognostic value of high-sensitivity cardiac troponin I early after coronary artery bypass graft surgery

Abstract Aims The diagnosis of periprocedural myocardial infarction (PMI) after coronary artery bypass graft (CABG) is based on biochemical markers along with clinical and/or instrumental findings. However, there is not a clear cut-off value of high-sensitivity cardiac troponin (hs-cTn) to identify PMI. We hypothesized that isolated hs-cTn concentrations in the first 24 h following CABG could predict cardiac adverse events (in-hospital death and PMI) and/or left ventricular ejection fraction (LVEF) decrease. Methods and results We retrospectively enrolled all consecutive adult patients undergoing CABG at our Institution over 1 year. Hs-cTnI concentrations (Access assay, Beckman-Coulter) were serially measured in the post-operative period and correlated with post-operative outcomes. 300 patients were enrolled; 71.3% of them underwent CABG alone, mainly on-pump (96.7%), 33.7% in the setting of an acute coronary syndrome. Most patients showed hs-cTnI values superior to the limit required by the latest guidelines for the diagnosis of PMI. Five patients (1.7%) died, 8% developed a PMI, and 10.6% showed a LVEF decrease ≥10%. Hs-cTnI concentrations did not correlate with death or PMI whereas they did correlate with LVEF decrease ≥ 10% (P-value &amp;lt; 0.05 at any time interval). Indeed, higher hs-cTnI values at 9–12 h post-operatively, along with previous cardiac surgery, number of surgical procedures, longer cardiopulmonary bypass time, and PMI diagnosis were predictors of LVEF decrease. Conclusions After CABG surgery, hs-cTnI at 9–12 h post-operatively may be a useful method to early identify patients at risk for LVEF decrease and to guide early investigation and management of possible post-operative complications.

AGE- AND CONTRACEPTIVE-SPECIFIC ANTI-MÜLLERIAN HORMONE REFERENCE VALUES FROM OVER 25,000 REPRODUCTIVE-AGE WOMEN

To determine age-specific median anti-Müllerian hormone (AMH) levels across contraceptive types in healthy women. Women aged 20 to 47 years of age, with no pre-existing comorbidities, who took the Modern Fertility Hormone Test were included in this study. AMH was determined using the Beckman Coulter Access assay, with values 0.1 to 24 ng/mL. Log transformed AMH values were analyzed using fitting generalized additive models (GAMs) accounting for age using quantile regression and assumed as the ratio of medians. For ages 20, 25, 30, 35, 40, and 45, predicted age specific median (95% confidence intervals) levels were assessed. A sensitivity analysis, adjusted for BMI, smoking frequency, CD3, testing lab, and age of menarche, was also performed. 25,763 healthy women reported their use of current contraceptive methods; no birth control: 16499 (64%), copper IUD: 926 (3.6%), hormonal IUD: 2955 (11.5%), implant: 477 (1.9%), progestin-only pill (POP): 260 (1.0%), combined oral contraceptive (OCP): 4059 (15.8%), ring: 587 (2.3%). AMH exhibited age-related declines regardless of the mode of contraception as shown by predicted median values and 95% CI. Median values at age 30 ranged from 3.39 ng/mL to 2.81 ng/mL across contraceptive types. In the adjusted analysis, median values were lower but the relationship was similar.Tabled 1202530354045No contraceptives4.23 (3.64 - 4.92)3.95 (3.78 - 4.11)3.33 (3.24 - 3.41)2.53 (2.46 - 2.60)1.46 (1.39 - 1.52)0.66 (0.59 - 0.74)OCP3.48 (2.76 - 4.40)3.49 (3.27 - 3.72)2.84 (2.72 - 2.97)2.07 (1.94 - 2.20)1.04 (0.90 - 1.19)0.38 (0.26 - 0.57)Hormonal IUD4.77 (3.70 - 6.14)3.97 (3.70 - 4.27)3.33 (3.18 - 3.49)2.51 (2.35 - 2.68)1.48 (1.29 - 1.71)0.73 (0.51 - 1.04)Copper IUD4.60 (3.42 - 6.17)4.12 (3.69 - 4.59)3.39 (3.17- 3.62)2.65 (2.43 - 2.90)1.84 (1.52 - 2.23)1.22 (0.78 - 1.92)Implant3.68 (2.51 - 5.38)3.60 (3.12 - 4.16)3.08 (2.80 - 3.40)2.09 (1.74 - 2.50)1.21 (0.75 - 1.95)0.66 (0.24 - 1.81)POP5.08 (3.06 - 8.43)3.94 (3.18 - 4.88)2.87 (2.53 - 3.25)1.88 (1.62 - 2.19)1.16 (0.85 - 1.59)0.69 (0.35 - 1.36)Ring3.79 (2.48 - 5.80)3.33 (2.77 - 4.02)2.81 (2.58 - 3.06)2.18 (1.97 - 2.41)1.59 (1.26 - 2.01)1.11 (0.66 - 1.89) Open table in a new tab Understanding and interpreting ovarian reserve in contraceptive users has been limited by the lack of comprehensive AMH reference values for various contraceptive methods. These data, the first AMH reference values by age and contraceptive type, may be used to more accurately estimate underlying ovarian reserve among contraceptive users.

Clinical evaluation of four commercial immunoassays for the detection of antibodies against established SARS-CoV-2 infection

A comparison of the clinical performance of the Elecsys Anti-SARS-CoV-2, Liaison SARS-CoV-2 S1/S2 IgG, Access SARS-CoV-2 IgG and Vitros Immunodiagnostic Products Anti-SARS-CoV-2 IgG immunoassays for the diagnosis of COVID-19 infection was performed.Patient sera were collected at least 6 weeks following onset of COVID-19 infection symptoms. Negative control specimens were stored specimens from those without COVID-19, collected in April–May 2019. Sensitivity and specificity with 95% confidence intervals (CI) were calculated. Linear regression was used to examine the relationship between the magnitude of serological response and clinical characteristics.There were 80 patients from whom 86 sera specimens were collected; six patients had duplicate specimens. There were 95 negative control specimens from 95 patients. The clinical sensitivity of the Elecsys assay was 98.84% (95% CI 93.69–99.97), specificity was 100% (95% CI 96.19–100.00); the Liaison assay clinical sensitivity was 96.51% (95% CI 90.14–99.27), specificity was 97.89% (95% CI 92.60–99.74); the Access assay clinical sensitivity was 84.88% (95% CI 75.54–91.70), specificity was 98.95% (95% CI 94.27–99.97); and the Vitros assay clinical sensitivity was 97.67% (95% CI 91.85–99.72), specificity was 100% (95% CI 96.15–100.00).A requirement for hospitalisation for COVID-19 infection was associated with a larger Vitros, Liaison and Access IgG response whilst fever was associated with a larger Elecsys response.All assays evaluated with the exception of the Access assay demonstrated similar performance. The Elecsys assay demonstrated the highest sensitivity and specificity.

Simultaneous determination of 8 beta-lactams and linezolid by an ultra-performance liquid chromatography method with UV detection and cross-validation with a commercial immunoassay for the quantification of linezolid

Linezolid and beta-lactams are anti-infective drugs frequently used in intensive care unit patients. Critical illness could induce alterations of pharmacokinetic parameters due to changes in the distribution, the metabolism and the elimination process. Therapeutic drug monitoring (TDM) is therefore recommended to prevent mainly under-dosing of beta-lactams or hematological and neurological toxicities of linezolid. In Multi-or Extensively-Drugs Resistant-Tuberculosis Bacteria, the regimen could include linezolid with meropenem and amoxicillin/clavulanate justifying the development of a method allowing their simultaneous quantification.The aim of this work was to develop an in-house ultra-performance liquid chromatography method with UV detection (UHPLC-PDA) allowing the simultaneous determination of 8 beta-lactams (amoxicillin, aztreonam, cefepime, ceftazidime, ceftriaxone, cefuroxime, meropenem and piperacillin) and linezolid and to cross-validate the linezolid quantification with a new commercial immunoassay (ARK kit) tested on a Cobas analyzer. The main advantages of the immunoassay are a 24/24 h random access assay which is fully automated and results provided within 2 h.The interference due to potential co-administrated drugs was evaluated on both methods. The preanalytical factors (type of matrix, stability) for linezolid were also investigated. The influence of hemolysis, icteria or lipemia on the spectroscopic detection of the immunoassay was assessed. The analytical performances were evaluated using the accuracy profiles approach with acceptance limits fixed at ±30%. Seventy patient samples were measured using both methods.No cross-reaction with the tested anti-infective drugs as well as no influence of hemolysis, lipemia, icteria were observed. The linezolid concentration could be measured on heparinized plasma or serum without a significant difference and remained stable for at least 72h at 4°C.The UHPLC-PDA method performed well in the analytical range investigated (0.25–50 mg/L for meropenem, 0.75–50 mg/L for linezolid and 1–200 mg/L for other beta-lactams) with an intermediate precision and a relative bias below 7.6 and 7.7%, respectively. The analytical range of the immunoassay was narrower, from 0.85 to 18.5 mg/L. The precision and relative bias were lower than 8.1% and 4.2%, respectively. Results obtained on clinical samples showed an acceptable difference between methods with a mean bias of -1.8% [95% confidence interval: -5.2% – 1.6%].To conclude, both methods showed acceptable performance to perform TDM of linezolid considering the therapeutic through target of 2-8 mg/L. The choice of the method should be made according to the degree of emergency of the response required and the field of application justifying or not the simultaneous quantification of beta-lactams and linezolid.

The interchangeability of two assays for the measurement of anti-Müllerian hormone when personalizing the dose of FSH in in-vitro fertilization cycles

Objective Study the interchangeability of Roche Elecsys and Beckman Coulter Access anti-Müllerian Hormone (AMH) assays to select the gonadotropin starting dose in IVF cycles. Methods Patients’ AMH was measured using both Elecsys and Access automated assays. AMH values were then used to calculate the FSH starting dose. The main outcome is the percentage of women that would have been stratified to a different dose of gonadotropin due to differences in AMH values from the two tests. Results The Access assay systematically gives higher values compared with the Elecsys assay (slope = 0.88). For Follitropin Alfa, the difference in starting dose was > 15% in 2/113 patients, when Access AMH was used instead of Elecsys. For Follitropin Delta the difference in the starting dose was >15% in 21/113 patients when using Access AMH. When considering women with high ovarian reserve, only 4/51 would have received a Follitropin Delta dose that exceeded a 15% difference using Access AMH as a substitute for the Elecsys value. Conclusions The use of the Roche Elecsys or Beckman Coulter Access leads to modest differences in AMH values, which seem to little affect the calibration of FSH dose used for ovarian stimulation.

Two-Hour Algorithm for Rapid Triage of Suspected Acute Myocardial Infarction Using a High-Sensitivity Cardiac Troponin I Assay.

We aimed to derive and externally validate a 0/2-h algorithm using the high-sensitivity cardiac troponin I (hs-cTnI)-Access assay. We enrolled patients presenting to the emergency department with symptoms suggestive of acute myocardial infarction (AMI) in 2 prospective diagnostic studies using central adjudication. Two independent cardiologists adjudicated the final diagnosis, including all available medical information including cardiac imaging. hs-cTnI-Access concentrations were measured at presentation and after 2 h in a blinded fashion. AMI was the adjudicated final diagnosis in 164 of 1131 (14.5%) patients in the derivation cohort. Rule-out by the hs-cTnI-Access 0/2-h algorithm was defined as 0-h hs-cTnI-Access concentration <4 ng/L in patients with an onset of chest pain >3 h (direct rule-out) or a 0-h hs-cTnI-Access concentration <5 ng/L and an absolute change within 2 h <5 ng/L in all other patients. Derived thresholds for rule-in were a 0-h hs-cTnI-Access concentration ≥50 ng/L (direct rule-in) or an absolute change within 2 h ≥20 ng/L. In the derivation cohort, these cutoffs ruled out 55% of patients with a negative predictive value (NPV) of 99.8% (95% CI, 99.3-100) and sensitivity of 99.4% (95% CI, 96.5-99.9), and ruled in 30% of patients with a positive predictive value (PPV) of 73% (95% CI, 66.1-79). In the validation cohort, AMI was the adjudicated final diagnosis in 88 of 1280 (6.9%) patients. These cutoffs ruled out 77.9% of patients with an NPV of 99.8% (95% CI, 99.3-100) and sensitivity of 97.7% (95% CI, 92.0-99.7), and ruled in 5.8% of patients with a PPV of 77% (95% CI, 65.8-86) in the validation cohort. Safety and efficacy of the l hs-cTnI-Access 0/2-h algorithm for triage toward rule-out or rule-in of AMI are very high. APACE, NCT00470587; ADAPT, ACTRN1261100106994; IMPACT, ACTRN12611000206921.

3301A novel high-sensitivity cardiac troponin i assay for early diagnosis of acute myocardial infarction

Abstract Background Lately, the novel high-sensitivity cardiac troponin I (hs-cTnI) Access assay was developed. Its clinical performance in patients presenting with chest pain to the emergency department (ED) is unknown. Purpose To clinically validate the novel hs-cTnI-Access assay and to derive and validate an assay specific 0/1h-algorithm accordingly to the European Society of Cardiology (ESC) recommendations. Methods In a prospective international multicentre study we enrolled patients presenting to the emergency department with symptoms suggestive of acute myocardial infarction (AMI). Final diagnoses were centrally adjudicated by two independent cardiologists including all clinical information including cardiac imaging twice: 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-Access was measured at presentation and at 1h. Primary objective was a direct comparison of diagnostic accuracy as quantified by the area under the receiver-operating-characteristic curve (AUC) of hs-cTnI-Access versus the two established hs-cTn assays (hs-cTnT-Elecsys, hs-cTnI-Architect). Secondary objectives included the derivation and internal validation of an hs-cTnI-Access specific 0/1h-algorithm. Results AMI was the adjudicated final diagnosis in 243/1579 (15.4%) patients. The AUC at presentation for hs-cTnI-Access was 0.95 (95% CI, 0.94–0.96), significantly higher as hs-cTnI-Architect (0.92 [95% CI, 0.91–0.94; p&lt;0.001]), and comparable to hs-cTnT-Elecsys (0.94 [95% CI, 0.93–0.95; p=0.12]) Applying the derived hs-cTnI-Access 0/1h-algorithm (derivation cohort n=686) to the internal validation cohort (n=680), 60% of patients were ruled-out (sensitivity 98.9% [95% CI, 94.3–99.8]), and 15% of patients were ruled-in (specificity 95.9% [95% CI, 94.0–97.2]). Patients ruled-out by the 0/1h-algorithm had a survival rate of of 100% after 30-days and 98.4% after two years of follow up. Findings were confirmed in the secondary analyses using the adjudication including serial measurements of hs-cTnI (Architect). Performance of the 0/1h-algorithm Conclusions Diagnostic accuracy of the novel hs-cTnI-Access assay is excellent and at least comparable to the two established hs-cTn assays. The assay-specific 0/1h-algorithm allows a safe rule-out and accurate rule-in of MI in about 75% of patients within 1-hour after presentation to the ED. Survival of patients ruled-out by the 0/1h-algorithm was very high. Acknowledgement/Funding Swiss National Science Foundation, the Swiss Heart Foundation, the KTI, the European Union, the Stiftung für kardiovaskuläre Forschung Basel

High-Sensitivity Cardiac Troponin I Assay for Early Diagnosis of Acute Myocardial Infarction.

The aim of this study was to validate the clinical performance of the Beckman Access high-sensitivity cardiac troponin I (hs-cTnI) 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 with all clinical information including cardiac imaging twice: 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 Access was measured at presentation and at 1 h. The primary objective was a direct comparison of diagnostic accuracy as quantified by the area under the ROC curve (AUC) of hs-cTnI Access vs the hs-cTnT Elecsys and hs-cTnI Architect assays. Secondary objectives included the derivation and validation of an hs-cTnI Access-specific 0/1-h algorithm. AMI was the adjudicated final diagnosis in 243 of 1579 (15.4%) patients. The AUC at presentation for hs-cTnI Access was 0.95 (95% CI, 0.94-0.96), higher than hs-cTnI Architect [0.92 (95% CI, 0.91-0.94; P < 0.001)] and comparable to hs-cTnT Elecsys [0.94 (95% CI, 0.93-0.95; P = 0.12)]. Applying the derived hs-cTnI Access 0/1-h algorithm (derivation cohort n = 686) to the validation cohort (n = 680), 60% of patients were ruled out [sensitivity, 98.9% (95% CI, 94.3-99.8)], and 15% of patients were ruled in [specificity, 95.9% (95% CI, 94.0-97.2)]. Patients ruled out by the 0/1-h algorithm had a survival rate of 100% at 30 days. Findings were confirmed in the secondary analyses by the adjudication including serial measurements of Architect hs-cTnI. Diagnostic accuracy and clinical utility of the Beckman hs-cTnI Access assay are very high and at least comparable to Roche hs-cTnT and Abbott hs-cTnI assays. ClinicalTrials.gov Identifier: NCT00470587.

Performance of anti-Müllerian hormone (AMH) levels measured by Beckman Coulter Access AMH assay to predict oocyte yield following controlled ovarian stimulation for in vitro fertilization.

PurposeWe evaluated the performance of anti‐Müllerian hormone (AMH) measured by the Beckman Coulter fully automated Access assay to predict oocyte yield following controlled ovarian stimulation (COS) for in vitro fertilization (IVF).MethodsThe correlation between the Access assay and the pre‐mixing method with Generation II ELISA assay (Gen II pre‐mix assay) was assessed using 230 blood samples. The relationship of AMH level measured by the Access assay and the actual number of oocytes retrieved following COS was assessed using 3296 IVF cycles. The performances of AMH, follicle stimulating hormone (FSH), and estradiol (E2) in predicting the responses to COS were also evaluated by constructing receiver operating characteristic (ROC) curves.ResultsThe AMH levels measured just before oocyte retrieval by the Access assay and the number of oocytes retrieved following COS showed a good correlation with R = 0.655. The ROC analysis revealed that the sensitivity of AMH was comparable with or lower than that of E2 but higher than that of FSH.ConclusionsWith the improved Access AMH assays, AMH was as sensitive as E2 and could become an accurate marker of ovarian response to COS in more than 3000 Japanese IVF patients.

Non-equivalence of anti-Müllerian hormone automated assays-clinical implications for use as a companion diagnostic for individualised gonadotrophin dosing.

STUDY QUESTIONCan anti-Müllerian hormone (AMH) automated immunoassays (Elecsys® and Access) be used interchangeably as a companion diagnostic for individualisation of follitropin delta dosing?SUMMARY ANSWERThe Access assay gives systematically higher AMH values than the Elecsys® assay which results in over 29% of women being misclassified to a different follitropin delta dose.WHAT IS KNOWN ALREADYFollitropin delta is the first gonadotrophin to be licenced with a companion diagnostic, the Roche Elecsys® AMH Plus assay. Alternative automated AMH assays including the Beckman Coulter Access immunoassay are considered to provide similar results, but clarification of their suitability as an off-licence companion diagnostic for follitropin delta is required.STUDY DESIGN, SIZE, DURATIONWe systematically searched the existing literature for studies that had measured AMH using both automated assays in the same cohort of women. Individual paired patient data were acquired from each author and combined with unpublished data.PARTICIPANTS/MATERIALS, SETTING, METHODSWe identified five eligible prospective published studies and one additional unpublished study. A 100% response from the authors was achieved. We collected paired AMH data on samples from 848 women. Passing–Bablok regression and Bland–Altman plots were used to compare the analytical performance of the two assays. The degree of misclassification to different treatment categories was estimated should the Access AMH be used as a companion diagnostic instead of the Elecsys AMH in determining the dosing of follitropin delta.MAIN RESULTS AND THE ROLE OF CHANCEThe Passing–Bablok regression shows a linear relationship (Access = −0.05 + 1.10 × Elecsys). The Access assay systematically gave higher values by an average of 10% compared with the Elecsys assay (slope = 1.10, 95% CI: 1.09 to 1.12). The average of the difference between the two assays was 2.7 pmol/l. The 95% limits of agreement were −11.7 to 6.3. Overall 253 (29.3%) women would have received an inappropriate follitropin delta dose if the Beckman Coulter Access assay was used. Specifically, a substantial proportion of women (ranging from 49% to 90% depending on the AMH category) would receive a lower dose of follitropin delta based on the Access AMH assay. Up to 10% (ranging from 2.5% to 10%) of women with high ovarian reserve would have been misclassified to a greater dose of follitropin delta based on the Access AMH assay.LIMITATIONS REASONS FOR CAUTIONWe compared the values of the two principal automated assays, extrapolation of our findings to other automated AMH assays would require similar comprehensive examination.WIDER IMPLICATIONS OF THE FINDINGSAn international standard for the calibration of the automated AMH assays is warranted to facilitate efficient use of AMH as a companion diagnostic. The variable calibration of alternative automated AMH assays may adversely impact on the performance of the follitropin delta dosing algorithm.STUDY FUNDING/COMPETING INTEREST(S)No formal funding has been received for this study. SI is funded by a UK Medical Research Council skills development fellowship (MR/N015177/1). SMN has received speakers fees, travel to meetings and participated in advisory Boards for Beckman Coulter, IBSA, Ferring Pharmaecuticals, Finox, Merck Serono, Merck and Roche Diagnostics. SMN has received research support from Ansh laboratories, Beckman Coulter, Ferring Pharmaceuticals and Roche Diagnostics.TRIAL REGISTRATION NUMBERN/A.

Diagnostic performance of serological assays for anti-HBs testing: Results from a quality assessment program

BackgroundPost-vaccination testing after hepatitis B vaccination is indispensable to evaluate long-term immunological protection. Using a threshold level of antibodies against hepatitis B surface antigen (anti-HBs) to define serological protection, implies reproducible and valid measurements of different diagnostic assays. ObjectivesIn this study we assess the performance of currently used anti-HBs assays. Study designIn 2013, 45 laboratories participated in an external quality assessment program using pooled anti-HBs serum samples around the cutoff values 10IU/l and 100IU/l. Laboratories used either Axsym (Abbott Laboratories), Architect (Abbott Laboratories), Access (Beckman-Coulter), ADVIA Centaur anti-HBs2 (Siemens Healthcare Diagnostics), Elecsys, Modular or Cobas (Roche Diagnostics) or Vidas Total Quick (Biomerieux) for anti-HBs titre quantification. We analysed covariance using mixed-model repeated measures. To assess sensitivity/specificity and agreement, a true positive or true negative result was defined as an anti-HBs titre respectively above or below the cutoff value by ≥4 of 6 assays. ResultsDifferent anti-HBs assays were associated with statistically significant (P<0.05) differences in anti-HBs titres in all dilutions. Sensitivity and specificity ranged respectively from 64%-100% and 95%-100%. Agreement between assays around an anti-HBs titre cutoff value of 10IU/l ranged from 93%-100% and was 44% for a cutoff value of 100IU/l. ConclusionsAround a cutoff value of 10IU/l use of the Access assay may result in false-negative results. Concerning the cutoff value of 100IU/l, a sample being classified below or above this cutoff relied heavily on the specific assay used, with both the Architect and the Access resulting in false-negative results.

Association between perfluoroalkyl substances and reproductive hormones in adolescents and young adults.

Few studies have explored the association between perfluoroalkyl substances (PFAS) and reproductive hormones in adolescents and young adults. This study aimed to investigate the association of PFAS with reproductive hormones in adolescents and young adults. We recruited 540 subjects aged 12-30 years from a 1992 to 2000 mass urine screening population and established a cohort from 2006 to 2008 via invitations by mail or/and telephone. Serum PFAS levels were analyzed with a Waters ACQUITY UPLC system coupled with a Waters Quattro Premier XE triple quadrupole mass spectrometer. Serum reproductive hormone levels were measured by immunoluminometric assay with an Architect random access assay system. PFAS levels were divided into different percentiles according to their detection limits in the multiple regression models to analyze associations between reproductive hormone levels and exposure with PFAS. The adjusted mean serum level of sex hormone-binding globulin (SHBG) decreased significantly in association with the <50th, 50-75, 75-90 and >90th percentile categories of perfluorooctanoic acid (PFOA) compared with a reference category for the females in the 12-17-year-old group. The follicle-stimulating hormone (FSH) levels were significantly decreased in association with the different percentile categories of perfluorooctane sulfonate (PFOS) in the male 12-17-year-old group and the different percentile categories of perfluoroundecanoic acid (PFUA) in the female 12-17-year-old group. The serum FSH levels in the females aged 12-17 were also decreased in association with the different percentile categories of PFUA. On the other hand, there was a significantly negative association between the different percentile categories of PFOS and the serum testosterone level among the female 12-17-year-old group. We found that the serum concentrations of PFOA, PFOS, and PFUA were negatively associated with the serum levels of SHBG, FSH, and testosterone in the young Taiwanese population and that these effects were the strongest in the females aged 12-17. Further studies are needed to determine whether these associations are causal.

Association between Perfluoroalkyl Substances and Reproductive Hormones in Adolescents and Young Adults

Association between Perfluoroalkyl Substances and Reproductive Hormones in Adolescents and Young AdultsAbstract Number:2130 Meng-Shan Tsai*, Chien-Yu Lin, Ching-Chun Lin, Ta-Chen Su, and Pau-Chung Chen Meng-Shan Tsai* Taiwan National University, Taiwan, E-mail Address: [email protected] Search for more papers by this author , Chien-Yu Lin Department of Internal Medicine, En Chu Kong Hospital, New Taipei City, Taiwan;School of Medicine, Fu Jen Catholic University, New Taipei City, Taiwan, Taiwan Search for more papers by this author , Ching-Chun Lin Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan, Taiwan Search for more papers by this author , Ta-Chen Su Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan, Taiwan Search for more papers by this author , and Pau-Chung Chen Department of Public Health and Institute of Occupational Medicine and Industrial Hygiene, National Taiwan University College of Public Health, Taipei, Taiwan;Department of Environmental and Occupatio, Taiwan Search for more papers by this author AbstractBackground: Perfluoroalkyl substances (PFASs) are highly bio-accumulative environmental pollutant. Some animal and epidemiological studies have proved that PFASs exposure disrupt the homeostasis of endocrine system and have health effects. The reproductive system is more susceptible and vulnerable to environmental pollutant than the other system in human body. However, few studies explore the association between PFASs and reproductive hormone in children and adolescence. Aims: The purpose of this study is to investigate the association of PFASs and reproductive hormone in young group.Methods: We recruited 540 subjects in the Young Taiwanese Cardiovascular Cohort. Serum level of PFASs were analyzed by a Waters ACQUITY UPLC system coupled with a Waters Quattro Premier XE triple quadrupole mass spectrometer; the level of serum reproductive hormone were measured by immunoluminometric assay in an architect random access assay system. We examined the association among serum level of PFASs and reproductive hormone by multiple linear regression.Results: Adjusted mean serum follicle-stimulating hormone (FSH) significantly decreased (p for trend = 0.04) across different categories (<25th, 25–50, 50-75 and >75th percentiles) of perfluorooctane sulfonate (PFOS) in male subjects aged 12-19. Female serum FSH in age 12-19 also decreased (p for trend = 0.01) across different categories of perfluoroundecanoic acid (PFUA). On the other hand, there was a significantly negative association (p for trend = 0.04) between different categories of PFOS and female serum testosterone in age 12-19.Conclusions: We found that serum concentration of PFASs was negatively associated with serum level of FSH and testosterone in Taiwan adolescent population. Further studies are needed to clarify whether these associations are causal.

Thyroglobulin antibody levels do not predict disease status in papillary thyroid cancer

Thyroglobulin antibodies (TgAb) are present in approximately 20% of patients with papillary thyroid cancer (PTC) and invalidate the serum thyroglobulin (Tg) level as a tumour marker. We examined whether trends in the TgAb level could serve as a surrogate marker of disease status in the surveillance of patients with PTC. All patients found to have a least one positive postoperative TgAb level (determined by the Beckman-Coulter Access Assay) after undergoing initial surgery for PTC from 2000 to 2010 at a single institution were included. Log-log transformation and linear regression were applied to longitudinal TgAb levels, yielding patient-specific regression coefficients that categorized as follows: highly negative, moderately negative and positive/no trend. The recurrence rate in each category was then assessed. Ninety-three of 967 patients with PTC were included. Recurrent disease was detected in 19 patients (20%) after a mean follow-up time of 51 months. Regression coefficients in the highly negative and moderately negative groups were not different, and hence these groups were pooled. The proportion of recurrent cases in the negative trend group was similar to that in the positive/no trend group (19.7% vs 21.9%, NS). The mean regression coefficients were similar for recurrent and nonrecurrent cases within both the negative trend group (-0.89 vs -0.80, NS) and the positive/no trend group (0.08 vs 0.33, NS). Trends in the TgAb level do not predict disease status in PTC in our experience. In the context of most commercially available TgAb assays, surveillance of TgAb-positive patients will hinge on high-quality imaging until a valid alternative serum marker to Tg is identified.

Development, characterization and clinical validation of new sensitive immunofluorometric assay for the measurement of serum thyroglobulin

In the last decade, data published stressed the role of highly-sensitive thyroglobulin (Tg) assays in the follow-up of differentiated thyroid carcinoma (DTC) patients. The present study describes a new, highly-sensitive Tg assay, compares it with an available commercial assay, and validates it in the follow-up of DTC patients. The immunofluorometric high-sensitivity Tg assay is based on monoclonal and polyclonal antibodies produced at our laboratories. It was validated in 100 samples of 87 patients with DTC submitted to total thyroidectomy, 87% of whom also received radioiodine. For correlation, all samples were also tested using a commercial Tg assay (Beckman Access) with functional sensitivity (FS) of 0.1 ng/mL. The new method showed FS of 0.3 ng/mL. The correlation between the two methods was good (r = 0.74; p < 0.0001). The diagnostic sensitivity was 88.9%, and it was increased to 100% when combined with neck US. This new, high-sensitivity Tg assay presented a good correlation with Beckman Access assay and with the clinical outcome of the patients. The continuous availability of a validated assay is an additional advantage for long term follow-up of DTC patients.