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Objectives Implementing fully automated analyzers has become a crucial safety step in blood donation centers. The Elecsys® assays were evaluated on the cobas e 801 module (Roche Diagnostics) for routine first-time blood donor screening. Materials & Methods Five Elecsys infectious disease assays were tested on the cobas e 801 module at Etablissement Francais du Sang, Montpellier, France (March–April 2018). The performance of Elecsys HIV Duo, Anti-HCV II, HBsAg II, Anti-HBc II, and Syphilis assays was compared with PRISM HIV O Plus, HCV, HBsAg, HBcore, and newbio pk TPHA assays (specificity analyses)/ARCHITECT Syphilis TP (sensitivity analyses), respectively. Specificity was determined in residual fresh serum samples from unselected first-time blood donors (n ≥ 5195 per parameter). Elecsys assay sensitivity was tested using 30 preselected, positively characterized samples per assay and compared with archived routine testing data for comparator assays. Results Across all parameters, specificities for repeatedly reactive samples ranged from 99.81–100.00% for Elecsys assays and 99.71–99.98% for comparator assays. Sensitivities of Elecsys and comparator assays were the same for hepatitis C (85.19%), hepatitis B surface antigen (70.00%), hepatitis B core antigen antibodies (100.00%), and syphilis (100.00%). The sensitivity of the Elecsys HIV Duo assay was higher than the comparator assay (83.33% vs. 76.67%), but the difference was not statistically significant. Conclusions Elecsys infectious disease assays on the cobas e 801 module demonstrated high specificity and sensitivity for screening first-time blood donor samples, and were comparable with other commercially available assays. The Elecsys assays are reliable tests for screening blood donations.

Background Data from literature shows that antigen tests are rapid and helpful tools for diagnosis of COVID-19. Aim This work aimed to evaluate the performances of the Elecsys SARS-CoV-2 Antigen test, in comparison to RT-qPCR, the gold standard. Methods A total of 110 swabs were tested; according to rRT-PCR, 76 were positive, and 34 were negative. The swabs were processed by Elecsys SARS CoV 2 Antigen assay (Roche Diagnostics GmbH, Mannheim, Germany), an electrochemiluminescence immunoassay (ECLIA). Results In a first evaluation, the overall sensitivity and specificity were 85% and 100%, respectively. It was noted that most of the discordant cases had cycle threshold (Ct) values > 28. Therefore, it was assumed a new measure to evaluate sensitivity and specificity, then samples with Ct values

Introduction Serological SARS-CoV-2 assays have an important role in guiding the pandemic response. This research aimed to compare the performance of 2 antinucleocapsid assays. Methods Serum from 49 HCWs was analysed at baseline and 6 months using the Abbott diagnostics SARS-CoV-2 IgG assay and the Roche Diagnostics Elecsys Anti-SARS-CoV-2 total antibody assay. Results At baseline, 14/49 participants (29%) demonstrated antibody reactivity using the Abbott assay. At 6 months, 4/14 participants (29%) continued to demonstrate reactivity. A total of 14/49 (29%) participants had detectable antibodies at baseline using the Roche assay. In total, 13/14 (93%) of participants demonstrated antibody reactivity at 6 months. The Abbott assay showed a statistically significant difference in the signal-to-threshold values of baseline reactive samples when repeated at 6 months (p = 0.001). This was not seen with the Roche assay (p = 0.51). Conclusion In this small study, the Roche Diagnostics Elecsys Anti-SARS-CoV-2 total antibody assay appears superior in performance to the Abbott diagnostics SARS-CoV-2 IgG assay in accurately detecting participants with a history of confirmed COVID-19 disease at 6 months follow-up. This finding should be born in mind in the planning of future seroprevalence studies, especially when considering the use of anti-nucleocapsid assays.

Background Serological testing provides a record of prior infection with SARS-CoV-2, but assay performance requires independent assessment. Methods We evaluated 3 commercial (Roche Diagnostics pan-IG, and Epitope Diagnostics IgM and IgG) and 2 non-commercial (Simoa and Ragon/MGH IgG) immunoassays against 1083 unique samples that included 251 PCR-positive and 832 prepandemic samples. Results The Roche assay registered the highest specificity 99.6% (3/832 false positives), the Ragon/MGH assay 99.5% (4/832), the primary Simoa assay model 99.0% (8/832), and the Epitope IgG and IgM 99.0% (8/830) and 99.5% (4/830), respectively. Overall sensitivities for the Simoa, Roche pan-IG, Epitope IgG, Ragon/MGH IgG, and Epitope IgM were 92.0%, 82.9%, 82.5%, 64.5% and 47.0%, respectively. The Simoa immunoassay demonstrated the highest sensitivity among samples stratified by days postsymptom onset (PSO), 21 days PSO (95.18%). Conclusions All assays demonstrated high to very high specificities while sensitivities were variable across assays.

Background We compared two serological assays from Roche Diagnostics in individuals with and without COVID-19 vaccination, namely the Elecsys Anti-SARS-CoV-2 assay (detecting antibodies against the nucleocapsid protein of SARS-CoV-2) and the Elecsys Anti-SARS-CoV-2 S assay (detecting antibodies against the spike protein of SARS-CoV-2). Methods With both assays, we analyzed 3033 serum samples collected from 2496 patients without COVID-19 vaccination. In addition, we studied 34 healthcare-workers who received two injections of the BNT162b2 COVID-19 vaccine from BioNTech/Pfizer three weeks apart and who had repeatedly determined their antibody response by both assays. Results In our cohort of patients without COVID-19 vaccination, 62.9% of all determinations were negative with both Roche assays and 31.5% were positive with both assays. In 5.6% of our cohort, however, there were discordant results with both assays (partly because initially discordant results of the two assays became concordantly positive over time). In the healthcare-workers with the COVID-19 vaccination, the results of the Roche anti-nucleocapsid assay remained negative throughout the observation period of 5 weeks after vaccination. The initially negative antibodies against the spike protein became positive with the Roche assay in all samples two weeks after the initial injection, and the serum concentrations of anti-spike antibodies increased constantly until 4–5 weeks after the initial injection. Conclusions Here, we provide information on serological testing with the two Roche assays, which may be important for the application of the two assays in clinical routine. There are differences in the pattern of antibodies in individuals with and without COVID-19 vaccination.

Introduction The cobas (Roche Diagnostics, Indianapolis, IN) HPV assay was approved by the US Food and Drug Administration for human papillomavirus (HPV) testing in SurePath (Becton Dickinson, Franklin Lakes, NJ) Papanicolaou specimens for cervical cancer prevention. To validate the cobas HPV assay in SurePath specimens in our institution, we compared its accuracy and clinical efficacy to that of the Cervista (Hologic, Marlborough, MA) HPV HR assay. Methods This study used 138 Papanicolaou (Pap) cytology specimens collected in SurePath preservative fluid at our institution in 2018. After Pap cytology testing, the residual specimens were split for testing with the cobas and Cervista assays. Polymerase chain reaction (PCR)-based HPV testing (GP5+/GP6+) was performed on specimens with discrepant results. Clinical follow-up data were reviewed. Results The cobas HPV and Cervista HPV HR assays showed good concordance (89.1%), with a kappa value of 0.78 (95% CI: 0.675-0.885). Fifteen specimens showed discrepant results between the 2 assays. Of 7 cases with cobas+/Cervista− results, 5 (71%) were confirmed positive by PCR. Of 8 cases with cobas−/Cervista+ results, 4 (50%) were confirmed positive by PCR. cobas HPV and Cervista HPV HR showed the same HPV-positive rate in cases of pathologically diagnosed ASC-H, LSIL, or HSIL. The sensitivities and specificities for detecting high-risk HPV of cobas HPV (93.7%, 97.3%) and Cervista HPV HR (92.1%, 94.7%) were comparable. The cobas HPV assay had false-negative results in 4 cases (5.2%) including 1 false-negative case that failed to predict CIN3. Conclusions The cobas HPV assay is valid in SurePath Pap cytology specimens for cervical cancer screening but has limitations of false-negative results with clinical implications.

BackgroundImmunochromatographic rapid antigen tests (RATs) emerged onto the COVID-19 pandemic testing landscape to aid in the rapid diagnosis of people with suspected SARS-CoV-2 infection. RATs are particularly useful where RT-PCR is not immediately available and symptoms suggestive of a high viral load and infectiousness are assumed. Several lateral flow immunoassays have been authorized for use under EUA and/or the CE mark, presenting varying overall clinical performance data generated by the manufacturer or by independent investigators. To compare the real-world clinical performance of commercially available rapid chromatographic immunoassays intended for the qualitative detection of SARS-CoV-2, we performed a systematic meta-analysis of published data.MethodsWe searched the MEDLINE®, Embase, BIOSIS and Derwent Drug File (ProQuest)for manufacturer-independent prospective clinical performance studies comparing SARS-CoV-2 RATs and RT-PCR assays. Only studies on lateral flow assays not needing a separate reader for retrieving the result were included, if data were available on viral load, patients’ symptom status, sample type, and PCR assay used. For better data comparability, recalculation of the studies’ single performance data confidence intervals using the exact Clopper–Pearson method was applied.ResultsWe could include 19 studies (ten peer-reviewed) presenting detailed clinical performance data on 11,209 samples with 2449 RT-PCR-positives out of study prevalence rates between 1.9–100 % and between 50– 100% symptomatic samples. Four studies directly compared two to three different RATs and 15 studies compared one RAT to RT-PCR. Overall specificity ranged, with one test outlier, between 92.4% (87.4– 95.9) and 100% (99.7–100), and overall clinical sensitivity varied between 28.9% (16.4–44.3) and 98.3% (91.1–99.7), depending on assay, population characteristics, viral load, and symptom status. Sensitivity in high-viral-load samples (cycle threshold ≤25) showed a considerable heterogeneity among the assays ranging from 66.7% to 100%.ConclusionOnly two RATs offered sufficient manufacturer-independent, real-world performance data supporting use for the detection of current SARS-CoV-2 infection in symptomatic or high-viral-load patient populations. Reliable positive predictive values require testing of symptomatic patients or asymptomatic individuals only in case of a high pre-test probability. If RATs are used for screening of asymptomatic cases in low-prevalence scenarios, a lower positive predictive value of the result has to be considered.

In laboratory medicine, reference intervals (RIs) are key decision support tools used to guide the clinical interpretation of numerical test results. Best practice suggests each laboratory establishes RIs in the local population prior to introducing an assay into routine clinical practice. The aim of this study was to define RIs for frequently requested biochemical/haematological parameters in a healthy adult Irish Caucasian population. A cross-sectional study of non-pregnant apparently healthy volunteers was conducted. Baseline demographics, anthropometric and laboratory measurements were recorded. In total, 37 commonly requested biochemical (serum, n = 26) and haematological (venous blood, n = 11) ISO15189:2012 accredited tests were analysed, using the Roche Cobas® Sebia Capillarys 3 Tera and Siemens Advia® 2120i platforms following standard operating procedures. RIs were defined according to the International Federation of Clinical Chemistry (IFCC) recommended method. Of 208 apparently healthy volunteers, 76 failed to meet the study inclusion criteria. The reference population comprised of 132 participants (males: n = 65, 49.2%) with a median age of 29.7 (18.1–62.2) years. RIs for the majority of biochemical/haematological parameters were broadly in accord with those provided by Pathology Harmony (UK)/Irish RI Harmonisation Project and the manufacturer Roche Diagnostics. However, the established RI defined for HbA1c: 27–37 mmol/mol was markedly different from that quoted nationally, HbA1c: 20–42 mmol/mol. Normative biological intervals established in a healthy adult Irish population for 37 commonly requested biochemical/haematological parameters will be a valuable aid to result interpretation in clinical laboratories after appropriate verification in accordance with ISO 15189: 2012.

We assessed the commutativity of Roche and Abbott thyroid assays in the diagnosis and management of subclinical hypothyroidism (SCH). The Roche and Abbott thyroid assays are used by approximately 75% of clinical laboratories in the UK.Consecutive samples received from primary care on patients with SCH who had a raised thyroid-stimulating hormone (TSH)10 mIU/L and a normal free thyroxine (fT4) from two laboratories using either Roche or Abbott thyroid assays were identified over 10 working days. Following identification, samples were analysed at the other site within 24 hours. Diagnostic and management discordance were studied using the relevant manufacturer-provided reference ranges.We identified 93 patients with SCH (53 using the Roche assay). Roche TSH and fT4 results were respectively 40% ± 15% and 16% ± 7% higher (P .001) compared to Abbott results. Of the 93 patients, 41 (44%) were concordant for SCH on both methods. Of the 53 patients with SCH on the Roche assays, 40 (75.5%) had normal thyroid function and 13 (24.5%) had SCH when analysed using the Abbott assays. Of the 40 patients with SCH on the Abbott assays, 28 (70%) had SCH and 12 (30%) had results indicative for levothyroxine replacement when analysed on the Roche assays. Of these 12 patients, four had TSH 10 mIU/L, five had low fT4 and three had both.The diagnosis and management of SCH is strikingly different when using TSH and fT4 assays provided by Abbott Laboratories and Roche Diagnostics. Clinicians and laboratorians should be aware that between-assay differences and variations in reference ranges will directly impact the diagnosis and management of subclinical hypothyroidism.

The rapid worldwide spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has propelled the rapid development of serologic tests that can detect anti–SARS-CoV-2 antibodies. These have been used for studying the prevalence and spread of infection in different populations, and helping establish a recent diagnosis of coronavirus disease 2019 (COVID-19), and will likely be used to confirm humoral immunity after infection or vaccination. However, nearly all lab-based high-throughput SARS-CoV-2 serologic assays require a serum sample from venous blood draw, limiting their applications and scalability. Here, we present a method that enables large-scale SARS-CoV-2 serologic studies by combining self or office collection of fingerprick blood with a volumetric absorptive microsampling device (Mitra, Neoteryx LLC) with a high-throughput electrochemiluminescence-based SARS-CoV-2 total antibody assay (Roche Elecsys, Roche Diagnostics Inc) that is emergency use authorization approved for use on serum samples and widely used by clinical laboratories around the world. We found that the Roche Elecsys assay has a high dynamic range that allows for accurate detection of SARS-CoV-2 antibodies in serum samples diluted 1:20 as well as contrived dried blood extracts. Extracts of dried blood from Mitra devices acquired in a community seroprevalence study showed near identical sensitivity and specificity in detection of SARS-CoV-2 antibodies compared with neat sera using predefined thresholds for each specimen type. Overall, this study affirms the use of Mitra dried blood collection device with the Roche Elecsys SARS-CoV-2 total antibody assay for remote or at-home testing as well as large-scale community seroprevalence studies.

Summary Objectives To highlight an analytical interference involving nefopam and its metabolites on urinary benzodiazepine screening with Enzyme Multiplied Immunoassay Technique (EMIT) Atellica CH from Siemens Healthineers, and to evaluate two other immunoassays: MULTIGENT on Architect from Abbott Diagnostics and Cloned Enzyme Donor Immunoassay (CEDIA) Thermo Fisher kits on Cobas from Roche Diagnostics. Case/methods An analytical interference was suspected for a 58-year-old-woman hospitalized for unexplained malaise. The urinary EMIT Atellica benzodiazepine immunoassay was positive. Screenings by liquid chromatography coupled with diode array detector (LC-DAD) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) identified nefopam and metabolites but no benzodiazepine. Drug-free urine has been spiked at different concentrations of nefopam (187,5–3000 μg/L) and tested on EMIT Atellica assay. Three urines from nefopam-treated patients and two negative controls have been selected to assess this cross-reactivity. Nefopam quantification has been performed by LC-DAD. Different immunoassays were evaluated: EMIT on Atellica, MULTIGENT on Architect and CEDIA on Cobas. Results Drug-free urines spiked with nefopam were negative on EMIT Atellica immunoassay. The interference observed was confirmed for nefopam-treated patients (2/3) on EMIT Architect. For one patient, an interference was observed with a low concentration of nefopam ( Discussion/conclusion Comparison of three immunoassay techniques revealed a heterogeneity of the interference. Nefopam metabolites may be responsible for this cross-reactivity, suggesting the importance of testing them during the kits evaluation phase. This study highlights the need to confirm immunoassay results by more specific techniques.

Measuring the Parathyroid hormone (PTH) levels assists in the investigation and management of patients with parathyroid disorders. Rapid PTH monitoring is a valid tool for accurate assessment intraoperatively. Rapid Electro-Analytical Device (READ) is a point-of-care device that uses impedance change between target and capture probe to assess the PTH concentration in undiluted patient plasma samples. The aim of this work focuses on evaluating the analytical performance of READ platform to Roche analyzer as a prospective clinical validation method. The coefficient of variation (CV) for intra-assay imprecision was

Objectives Serological assays for detection of SARS-CoV-2 antibodies are increasingly used during the COVID-19 pandemic caused by the SARS-Coronavirus-2. Here we evaluated the analytical and clinical performance of three commercially available SARS-CoV-2 antibody assays. Methods A total of 186 samples from 58 patients with PCR-confirmed COVID-19 infection were measured using SARS-CoV-2 antibody assays by Siemens Healthineers, Roche Diagnostics and Euroimmun. Additionally, 123 control samples, including samples collected before December 2019 and samples with potential cross-reactive antibodies were analyzed. Diagnostic specificity, sensitivity, agreement between assays and ROC curve-derived optimized thresholds were determined. Furthermore, intra- and inter-assay precision and the potential impact of interfering substances were investigated. Results SARS-CoV-2 antibody assays by Siemens and Roche showed 100% specificity. The Euroimmun assay had 98 and 100% specificity, when borderline results are considered as positive or negative, respectively. Diagnostic sensitivity for samples collected ≥14 days after PCR-positivity was 97.0, 89.4 and 95.5% using the Siemens, Roche and Euroimmun assay, respectively. Sensitivity of the Roche assay can be increased using an optimized cut-off index (0.095). However, a simultaneous decrease in specificity (98.4%) was observed. Siemens showed 95.8 and 95.5% overall agreement with results of Euroimmun and Roche assay, respectively. Euroimmun and Roche assay exhibited 92.6% overall agreement. Discordant results were observed in three COVID-19 patients and in one COVID-19 patient none of the investigated assays detected antibodies. Conclusions The investigated assays were highly specific and sensitive in detecting SARS-CoV-2 antibodies in samples obtained ≥14 days after PCR-confirmed infection. Discordant results need to be investigated in further studies.

HIV prevalence in Oman is low (5 %). HIV screening is performed at regional public health laboratories as part of a medical fitness programme for residency applicants. We conducted a retrospective evaluation of indeterminate serology results from 11 females of African origin, aged 21–43 years. Serology testing for HIV was conducted according to the national Oman algorithm: fourth-generation immunoassays (Bio-Rad GS HIV Combo Ag/Ab EIA, Siemens Enzygnost HIV Integral 4, Abbott ARCHITECT HIV Ag/Ab Combo, Roche Elecsys HIV Combi PT, bioMérieux VIDAS HIV DUO QUICK), confirmatory assays (Geenius HIV 1/2 Confirmatory, INNO-LIA HIV I/II Score) and PCR testing. Confirmatory testing to resolve indeterminate results was conducted with available samples for five patients using a combination of immunoassays, confirmatory assays, PCR/PERT and pro-viral DNA levels, at three external laboratories; Roche Diagnostics (Germany), Swiss National Laboratory (Switzerland) and Barts Health NHS Trust (UK). Nineteen serum, 15 plasma and two whole-blood samples were analysed. Nine of ten patients analysed on Bio-Rad and Siemens immunoassays were highly reactive; seven were highly reactive on the Abbott assay. Eight of nine patients tested with the Roche assay were negative. Three of four patients tested on the bioMérieux assay were negative. Five patients underwent confirmatory testing at external laboratories; all were negative by HIV-RNA or pro-viral DNA testing. In conclusion, HIV-RNA and pro-viral DNA testing is recommended for HIV screening of individuals from high-prevalence regions coming to low-prevalence regions.

The urgent need to implement and rapidly expand testing for severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) infection has led to the development of multiple assays. How these tests perform relative to one another is poorly understood. We evaluated the concordance between the Roche Diagnostics cobas 6800 SARS‐CoV‐2 test and a laboratory‐developed test (LDT) real‐time reverse transcription‐polymerase chain reaction based on a modified Centers for Disease Control and Prevention protocol, for the detection of SARS‐CoV‐2 in samples submitted to the Clinical Laboratories of the Mount Sinai Health System. A total of 1006 nasopharyngeal swabs in universal transport medium from persons under investigation were tested for SARS‐CoV‐2 as part of routine clinical care using the cobas SARS‐CoV‐2 test with subsequent evaluation by the LDT. Cycle threshold values were analyzed and interpreted as either positive (“detected” or “presumptive positive”), negative (not detected), inconclusive, or invalid. Statistical analysis was performed using GraphPad Prism 8. The cobas SARS‐CoV‐2 test reported 706 positive and 300 negative results. The LDT reported 640 positive, 323 negative, 34 inconclusive, and 9 invalid results. When excluding inconclusive and invalid results, the overall percent agreement between the two platforms was 95.8%. Cohen's κ coefficient was 0.904 (95% confidence interval, 0.875‐0.933), suggesting almost perfect agreement between both platforms. An overall discordance rate of 4.2% between the two systems may reflect differences in primer sequences, assay limit of detection, or other factors, highlighting the importance of comparing the performance of different testing platforms., Highlights In this study, we compared the detection of SARS‐CoV‐2 in clinical samples from patients being evaluated for CoVID‐19 infection by two different RT‐PCR assays, the cobas® 6800 SARS‐CoV‐2 test from Roche Molecular Systems and a laboratory‐developed test (LDT) using the Centers for Disease Control and Prevention 2019‐nCoV primers and probes. Overall there was excellent agreement between the two tests methods, although our results suggest that the cobas® SARSCoV‐2 test may have a lower limit of detection than the LDT.

BACKGROUND The Cobas u411 Analyzer (Roche Diagnostics) is an automated, reflectance photometry-based urinalysis instrument designed for use with Roche's CHEMSTRIP 10UA technology and human urine samples. OBJECTIVE We aimed to optimize and validate the Cobas u411 Analyzer for use in canine and feline urinalysis. METHODS Patient urine samples presenting to the Clinical Pathology Laboratory at the Colorado State University Veterinary Teaching Hospital were analyzed with the Cobas u411 and by manual readings in parallel. Initially, 223 canine and 83 feline urine samples were run using the u411 factory settings. Following comparisons with manual results, and evaluation for directional bias, adjustments to the reflectance values were made in the instrument's programming. An additional 183 canine and 95 feline samples were run using the adjusted settings. Total urine protein concentrations were measured in 48 samples and used to generate receiver operating characteristic curves for the protein test pad. RESULTS Following adjustments in reflectance programming, concordance between u411 and manual results was increased by 17.7% for protein, 11.7% for ketones, and 4.5% for bilirubin. Concordances for pH, glucose, and blood were not substantially changed. Discordance for all analytes was ≤3%. Canine and feline samples had similar levels of discordance, though marginal concordance was higher in dogs for ketones, bilirubin, and blood. CONCLUSIONS Adjustments to the reflectance programming of the Cobas u411 Analyzer improved concordance with manual results for canine and feline samples. This instrument has the potential to greatly increase both efficiency and consistency of urinalysis procedures in higher throughput veterinary diagnostic laboratories.

Introduction. Mycoplasma genitalium is a sexually transmitted organism with high levels of resistance to the recommended first-line therapy, azithromycin. The ResistancePlus MG test concurrently detects M. genitalium, and the presence of macrolide-resistance mutations (MRM). European, UK and Australian guidelines recommend a diagnostic test that reports MRM to optimize treatment through resistance-guided therapy. Hence, for samples collected for use on other platforms, reflex testing using the ResistancePlus MG test would be beneficial.Aim. To validate the ResistancePlus MG assay using samples collected in Aptima buffer for testing on the Hologic Panther.Methodology. Positive (n=99) and negative (n=229) clinical samples collected in Aptima buffer were extracted on the MagNA Pure 96 (Roche Diagnostics), and tested with the ResistancePlus MG test on the LightCycler 480 II (Roche Diagnostics). Results were compared to matched samples collected using standard sample collection (urine or swab resuspended in PBS), with positive percent agreement (PPA), negative percent agreement (NPA) and Cohen's Kappa statistic.Results. The ResistancePlus MG test had high performance with a 200 µl input volume (PPA/NPA for M. genitalium detection, 92.9 % [95 % confidence interval (CI): 85.5-96.9]/100 % [95 % CI: 97.9-100], MRM detection, 96.9 % [95 % CI: 88.2-99.5]/85.7 % [95 % CI: 66.4-95.3]) and for 1 ml input volume (PPA/NPA for M. genitalium detection, 95.9%/96.6%, MRM detection, 98.4%/90.3%). Samples remained positive after storage at room temperature beyond the manufacturer-recommended storage of

Background Carbamazepine is an effective drug for treating seizures and trigeminal neuralgia. Therapeutic drug monitoring of free carbamazepine in serum can be useful in situations that drug--protein binding is altered to guide regimen adjustment and to aid in the diagnosis of clinical toxicity. Methods Separation of the nonprotein bound carbamazepine was achieved via ultrafiltration through a molecular weight cut-off filter. A method for free carbamazepine measurement was developed on the automated cobas chemistry analyzers (Roche Diagnostics) by modifying the Carbamazepine Gen 4 assay (Roche Diagnostics). Assay performance characteristics were established including precision, accuracy, reportable range, analytical specificity, and stability. Results The intra- and inter-assay imprecision was 0%-1.4% and 2.4%-5.1%, respectively. The lower limit of quantitation was 0.3 µg/mL, and the assay was linear up to 10.0 µg/mL. A spike recovery study, using reference standard material, showed recovery was 93.5%--101.3% across the analytical measurement range. Method comparison with a reference laboratory method demonstrated equivalent performance with a slope of 1.01, intercept of 0.09, and correlation coefficient of 0.9948. Conclusion This assay provides a simple and accurate method for monitoring free carbamazepine with a fast turnaround time.

Objective In January 2018, Roche Diagnostics calibrated CoaguChek XS PT Test Strips to the latest World Health Organization reference preparation. On September 12, 2018, Roche Diagnostics issued an urgent medical device correction statement warning of inaccurate international normalized ratio (INR) results greater than 4.5 and recommended additional confirmatory testing. Eight weeks later, on November 2, the U.S. Food and Drug Administration issued a class I recall of all affected lot numbers. The objective of this project was to determine the clinical effects of recalibration of CoaguChek on patients managed by the Anticoagulation Management Services (AMS). Methods Two retrospective chart reviews were conducted for patients seen by AMS from May 1 to September 11 and from September 12 to November 2, 2018. Data collected included date of INR, confirmatory testing (if applicable), reason for elevated INR, and interventions. Data were analyzed using descriptive statistics. Results From May 1 to September 11, 2018, 16 of 166 patients were affected by recalibrated strips, resulting in 19 of 1176 INRs being greater than 4.5. Almost half (47%) of elevations were due to unknown causes, and most were corrected by holding at least 1 dose. Of the 152 patients treated from September 12 to November 2, 8 patients were affected by the recalibration, resulting in 11 of 453 INRs being greater than 4.5. Six resulted in confirmatory INR testing with an average difference of 2 points. No bleeding events or hospitalizations were reported in either group. Conclusion Based on the experiences of 1 anticoagulation clinic, the CoaguChek XS PT Test Strip calibration update and class I recall did not result in a meaningful clinical impact.

Immunoassays are widely used as screening tests for HIV and syphilis in clinical, public health, and research settings. For syphilis, immunoassays are used in 'reverse syphilis algorithms' that start with treponemal tests such as syphilis IgG or syphilis total antibodies for the initial screen. Many screening immunoassays for HIV and syphilis use signal-to-cutoff (S/CO) values for determining positivity, with a cutoff value such as 1.0 differentiating positive from negative. Published literature indicates that the S/CO value often correlates with the likelihood of subsequent confirmation of HIV and syphilis infections, with low S/CO values barely exceeding the cutoff more likely to represent false positive screens. The data in this article present results from the Roche Diagnostics Elecsys HIV combi PT Assay and the Elecsys Syphilis Assay. The data include 19,368 syphilis total antibody screening results on 15,764 unique patients and 28,952 HIV screening results on 24,556 unique patients, S/CO values, clinical area where testing was ordered, sex, and age. For samples with positive syphilis total antibody screens, the data also include results of RPR (the immediate next step in the reverse algorithm), Treponema pallidum particle agglutination (TP-PA; for those samples in which RPR was non-reactive in the testing cascade), and clinical information and other testing related to diagnosis of syphilis. For positive HIV screens, the data also include HIV antibody differentiation results, HIV-1 PCR or HIV-2 results results (if performed), and clinical information related to diagnosis of HIV. The distributions of S/CO values relative to confirmation status were analyzed.

BackgroundThe Elecsys® Anti-SARS-CoV-2 S immunoassay (Roche Diagnostics International Ltd, Rotkreuz, Switzerland) has been developed for the in vitro quantitative detection of antibodies to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein. We evaluated the performance of this assay using samples from seven sites in Germany, Austria, and Switzerland.MethodsAnonymized frozen, residual serum, or plasma samples from blood donation centers or routine diagnostic testing were used for this study. For specificity and sensitivity analyses, presumed negative samples collected before October 2019 and SARS-CoV-2 PCR-confirmed single or sequential samples were tested, respectively. The performance of the Elecsys Anti-SARS-CoV-2 S immunoassay was also compared with other commercial immunoassays.ResultsThe overall specificity (n=7880 pre-pandemic samples) and sensitivity (n=240 PCR-positive samples [≥14 days post-PCR]) for the Elecsys Anti-SARS-CoV-2 S immunoassay were 99.95% (95% confidence interval [CI]: 99.87–99.99) and 97.92% (95% CI: 95.21– 99.32), respectively. Compared with seven other immunoassays, the Elecsys Anti-SARS-CoV-2 S assay had comparable or greater specificity and sensitivity. The Elecsys Anti-SARS-CoV-2 S immunoassay had significantly higher specificity compared with the LIAISON® SARS-CoV-2 S1/S2 IgG, ADVIA Centaur® SARS-CoV-2 Total, ARCHITECT SARS-CoV-2 IgG, iFlash-SARS-CoV-2 IgM, and EUROIMMUN Anti-SARS-CoV-2 IgG and IgA assays, and significantly higher sensitivity (≥14 days post-PCR) compared with the ARCHITECT SARS-CoV-2 IgG, iFlash-SARS-CoV-2 IgG and IgM, and EUROIMMUN Anti-SARS-CoV-2 IgG assays.ConclusionThe Elecsys Anti-SARS-CoV-2 S assay demonstrated a robust and favorable performance across samples from multiple European sites, with a very high specificity and sensitivity for the detection of anti-S antibodies.

STUDY QUESTION Which endometriosis classification, staging and reporting systems have been published and validated for use in clinical practice? SUMMARY ANSWER Of the 22 endometriosis classification, staging and reporting systems identified in this historical overview, only a few have been evaluated, in 46 studies, for the purpose for which they were developed. WHAT IS KNOWN ALREADY In the field of endometriosis, several classification, staging and reporting systems have been developed. PARTICIPANTS/MATERIALS, SETTING, METHODS A systematic PUBMED literature search was performed. Data were extracted and summarized. MAIN RESULTS AND THE ROLE OF CHANCE Twenty-two endometriosis classification, staging and reporting systems have been published between 1973 and 2021, each developed for specific, and different, purposes. There still is no international agreement on how to describe the disease. Studies evaluating the different systems are summarized showing a discrepancy between the intended and the evaluated purpose, and a general lack of validation data confirming a correlation with pain symptoms or quality of life for any of the current systems. A few studies confirm the value of the ENZIAN system for surgical description of deep endometriosis. With regards to infertility, the endometriosis fertility index has been confirmed valid for its intended purpose. LARGE SCALE DATA NA. LIMITATIONS, REASONS FOR CAUTION The literature search was limited to PUBMED. Unpublished classification, staging or reporting systems, or those published in books were not considered. WIDER IMPLICATIONS OF THE FINDINGS It can be concluded that there is no international agreement on how to describe endometriosis or how to classify it, and that most classification/staging systems show no or very little correlation with patient outcomes. This overview of existing systems is a first step in working toward a universally accepted endometriosis classification. STUDY FUNDING/COMPETING INTEREST(S) The meetings and activities of the working group were funded by the American Association of Gynecologic Laparoscopists, European Society for Gynecological Endoscopy, European Society of Human Reproduction and Embryology and World Endometriosis Society. A.W.H. reports grant funding from the MRC, NIHR, CSO, Wellbeing of Women, Roche Diagnostics, Astra Zeneca, Ferring, Charles Wolfson Charitable Trust, Standard Life, Consultancy fees from Roche Diagnostics, AbbVie, Nordic Pharma and Ferring, outside the submitted work. In addition, A.W.H. has a patent Serum biomarker for endometriosis pending. N.P.J. reports personal fees from Abbott, Guerbet, Myovant Sciences, Vifor Pharma, Roche Diagnostics, outside the submitted work; he is also President of the World Endometriosis Society and chair of the trust board. S.M. reports grants and personal fees from AbbVie, and personal fees from Roche outside the submitted work. C.T. reports grants, non-financial support and other from Merck SA, non-financial support and other from Gedeon Richter, non-financial support from Ferring Pharmaceuticals, outside the submitted work and without private revenue. K.T.Z. reports grants from Bayer Healthcare, MDNA Life Sciences, Roche Diagnostics Inc, Volition Rx, outside the submitted work; she is also a Board member (Secretary) of the World Endometriosis Society and World Endometriosis Research Foundation, Research Advisory Board member of Wellbeing of Women, UK (research charity), and Chair, Research Directions Working Group, World Endometriosis Society. The other authors had nothing to disclose. TRIAL REGISTRATION NUMBER NA.

To study the diagnostic characteristics of test systems for detecting antibodies to SARS-Cov-2. We studied the diagnostic characteristics of two test systems for detecting antibodies to SARS-Cov-2, registered in the Russian Federation. The first test system is a kit for detecting total antibodies to SARS-Cov-2 using immunochemiluminescence analysis on the «Cobas e 411» analyzer («Roche Diagnostics», Germany). The second test system is a kit for detecting IgM and IgG to SARS-Cov-2 («Core Technology Co., Ltd», China) by immunochromatographic analysis. The biological material for the study was blood serum. We assessed: diagnostic sensitivity, diagnostic specificity, and predictive value of positive and negative results. In the test system for detecting total antibodies to SARS-CoV-2, using an IHLA, the diagnostic sensitivity and specificity were 100%; the predictive value of positive and negative results was 100%. In the test system for the detection of IgM and IgG to Sars-CoV-2, using IHA, diagnostic sensitivity for IgM and IgG were 100%; diagnostic specificity for IgM - 60%, for IgG - 72%; predictive value of a positive result for IgM - 60%, IgG - 68,18%; predictive value of negative results for IgM and IgG - 100%. The best diagnostic characteristics were found in the test system for the detection of total antibodies to SARS-Cov-2, which must be taken into account when deciding whether to purchase test systems for the detection of antibodies to SARS-Cov-2.

BackgroundDetection of viral RNA by nucleic acid amplification testing (NAAT) remains the gold standard for diagnosis of SARS-CoV-2 infection but is limited by high cost and other factors. Whether serology-based assays can be effectively incorporated into a diagnostic algorithm remains to be determined. Herein we describe the development of a serology-based testing algorithm for SARS-CoV-2 infection.Patients and MethodsBetween July 2020 and February 2021, we included symptomatic unvaccinated patients evaluated in the Emergency Department of our institution for suspected SARS-CoV-2. All patients had testing by real-time Reverse Transcription Polymerase Chain Reaction. The performance characteristics of five commercial enzymatic serology assays testing for different antibody isotypes were evaluated in a derivation cohort and the assay with the best performance was further tested on a validation cohort. Optimal cut-off points were determined using receiver operating characteristic (ROC) curves and further tested using logistic regression.ResultsThe derivation and validations cohorts included 72 and 319 patients, respectively. Based on its initial performance, the Elecsys Anti-SARS-CoV-2 assay (Roche Diagnostics) was further tested in the validation cohort. Using ROC curve analysis, we estimated the diagnostic performance for different cut-off points assuming a prevalence of positive tests of 5%. At any given cut-off point the NPV was over 97%.DiscussionThis study suggests that an initial diagnostic strategy using the Elecsys Anti-SARS-CoV-2 serology test in symptomatic unvaccinated patients could help to rule out an acute SARS-CoV2 infection and potentially lead to appropriately tailored infection control measures or rational guidance for further testing with a potential cost reduction and increased availability.

One of the challenges for control and prevention of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection is the early diagnostic at the point of care. Several tests based on qualitative antigen detection have been developed; one of these is Elecsys SARS‐CoV‐2 Antigen immunoassay (Roche Diagnostics). In total, 523 nasopharyngeal swabs were randomly selected with the aims to evaluate sensitivity, specificity, cross‐reactivity, positive and negative predictive value (PPV, NPV), and agreement of Elecsys SARS‐CoV‐2 Antigen immunoassay using reverse transcription‐polymerase chain reaction (RT‐PCR) STAT‐NAT® coronavirus disease‐2019 as reference test. Cross‐reactivity was estimated using samples positive by RT‐PCR to other respiratory viruses (influenza virus, parainfluenza virus, rhinovirus, coronavirus OC43, and HKU1). The overall sensitivity of Elecsys SARS‐CoV‐2 Antigen was 89.72% (288/321); specificity was 90.59% (183/202); and cross‐reactivity to other respiratory viruses were not detected. Elecsys SARS‐CoV‐2 Antigen immunoassay showed a high sensitivity in samples with cycle threshold value, Highlights Elecsys SARS‐CoV‐2 Antigen assay can be used as an alternative tool or in complement with RT‐PCR to reduce SARS‐CoV‐2 transmission.Our results indicate that Elecsys SARS‐CoV‐2 Antigen assay detects SARS‐CoV‐2 infected persons independently of viral load.Elecsys SARS‐CoV‐2 Antigen assay has good performance characteristics to be used for SARS‐CoV‐2 infection tracing.

Vaccination against the ongoing COVID-19 is the key point in fight against the pandemic. The Spike (S) glycoprotein of SARS-CoV-2 is the major target of the neutralizing humoral response. We evaluated analytical and clinical performances of a surrogate virus neutralization test (sVNT) (iFlash-2019-nCoV Nab assay, Ylho, China) compared to the conventional neutralization tests (cVNT) and anti-S eCLIA assays (Roche Diagnostics, Switzerland) in recovered and/or vaccinated health care workers. Our results indicate that sVNT displayed high specificity and no cross reactivity. Both Roche and iFlash immunoassays were good in identifying cVNT serum dilution > 1:16. Optimal thresholds in identifying cVNT titers ≥ 1:16, were 74.5 U/ml and 49.4 IU/ml for anti-S eCLIA and sVNT, respectively. Our data show that Nab neutralizing antibodies titers depend on individuals and may abate over time. Specific assays such as sVNT may be a reliable complementary tool to routine anti-S serology assays.

International audience; Background: Discharging patients home as quickly as possible, or gaining the ability to eliminate a serious event is a goal requested by clinicians in the emergency department (ED). For this, risk scores, taking into account co-morbidities, have been established. The aim of our study consists to evaluate in patients with chest pain admitted in ED the risk stratification obtained with clinico-biological risk scores (CCS, GRACE score, TIMI score and HEART score) using Ortho hs-cTnI assay (Ortho Clinical Diagnostics, Illkirch, France) on the Vitros 3600® instrument or Roche hs-cTnT assay on the Cobas8000/e801® module (Roche diagnostics, Meylan, France), with comparison to hs-cTn-only strategy. Prognostic performances were evaluated according to AMI with or without STEMI, and deaths during hospitalization.Methods: Patients admitted to the ED presenting chest pain or symptoms suggesting of acute coronary syndrome (ACS) were included. Hs-cTnT was performed on a Roche hs-cTnT assay on the Cobas8000/e801® module using a fifth-generation assay and was used for the clinical diagnosis. In addition, hs-cTnI was tested using Ortho hs-cTnI assay on the Vitros 3600® analyzer. Retrospectively, we collected the variables needed for each score in clinical records. Our endpoint were occurrence of AMI in patients with chest pain after presentation to the ED and all cause death during the hospitalization.Results: We enrolled 160 patients with suspected ACS. The adjudicated diagnosis was AMI in 37 patients (with 9 STEMI and 28 NSTEMI), cardiac pathologies in 57 patients and other causes in 66 patients. The majority of patients were classified at high risk for each risk scores (from 42% to 68%) whatever the considered hs-cTn assay, except for TIMI score. Cohen's kappa agreements with GRACE, TIMI and HEART scores were excellent between Roche hs-cTnT vs Ortho hs-cTnI. The AUC of the HEART score was highest for both hs-cTn to predict AMI, NSTEMI or death, with no statistical difference according to the hs-cTn (p = NS) assay used. NRI analysis confirmed the interest of HEART score which improved individual risk prediction for AMI (or NSTEMI) and death.Conclusion: In view of our results, the decision aids using only biological variables (hs-cTn-only strategy and CCS) would seem more effective for rule-out AMI whereas bioclinical risk scores could better identify patients at low and high risk for mortality. In consequence, risk scores taking in account comorbidities, appear necessary to determine the outcome and thus to adapt the therapeutic options. It is interesting to note that the HEART score could be useful for the rule out AMI but also for the risk prediction as confirmed by the NRI.

OBJECTIVES Biotin therapy can affect the results of many immunoassay procedures. The present study investigates biotin's interference on 25-hydroxy vitamin D (25-OHD), parathyroidhormone (PTH) and thyroid-stimulating hormone (TSH) tests using four different assay systems and biotin neutralization. DESIGN AND METHODS Enrolled in the study were 50 children diagnosed with biotinidase deficiency (BTD) undergoing treatment with biotin (5-20 mg/day) who were subjected to a series of analyses involving 25-OHD (Roche Diagnostics assays, Beckman Coulter assays, HPLC, LC/MS-MS), TSH, PTH (Roche Diagnostics assays, Beckman Coulter assays) and biotin (LC/MS-MS), before and after biotin neutralization with Streptavidin-coated magnetic particles (SMP). RESULTS The median biotin concentration was found to be 175.2 [94.0-307.1] μg/L. There was no significant difference in the 25-OHD results before and after neutralization with the Beckman Coulter, HPLC and LC-MS/MS assays. In contrast, the median 25-OHD level was seen to decrease from 90.2 [35.9-105.3] ng/mL to 29.1 [22.6-37.6] ng/mL after neutralization with the Roche assay (p

BackgroundWidely available rapid testing is pivotal to the fight against COVID-19. Real-time reverse transcription-polymerase chain reaction (rRT-PCR) remains the gold standard. We compared two frequently used commercial rapid diagnostic tests (RDTs) for SARS-CoV-2-antigens, the SD Biosensor SARS-CoV-2 Rapid Antigen Test (Roche Diagnostics) and the Panbio COVID-19 Ag Rapid Test (Abbott Diagnostics), against rRT-PCR for SARS-CoV-2 detection.MethodsWe compared the tests in 2215 all-comers at a diagnostic centre between February 1 and March 31, 2021. rRT-PCR-positive samples were examined for SARS-CoV-2 variants.Findings338 participants (15%) were rRT-PCR-positive for SARS-CoV-2. The sensitivities of Roche-RDT and Abbott-RDT were 60.4% and 56.8% (PInterpretationThe sensitivities of the two RDTs are unsatisfactory. This calls into question whether their widespread use is effective in the ongoing SARS-CoV-2 pandemic.FundingSYNLAB Holding Deutschland GmbHResearch in contextEvidence before this studySmall studies and a meta-analysis from the Cochrance collaboration indicate vastly different diagnostic efficacies of commercial rapid diagnostic tests (RDTs) for SARS-CoV-2 antigen. The impact of SARS-CoV-2 variants has not been known.Added value of this studyThis is one of the largest real-world studies of the diagnostic efficacy of two widely recommended RDTs SARS-CoV-2 antigen in comparison to rRT-PCR. The sensitivities of the two RDTs are unsatisfactory, mainly in asymptomatic persons. Presence of the SARS-CoV-2 Alpha Variant decreased both tests’ sensitivities significantly.Implications of all the available evidencePolicy and health care providers should account for substantial limitations of RDTs for SARS-CoV-2 particular in asymptomatic persons. Research into alternative approaches to the screening for SARS-CoV-2 should be intensified.

Background This report describes a manufacturer‐independent evaluation of the diagnostic accuracy of the Elecsys SARS‐CoV‐2 antigen assay from Roche Diagnostics in a tertiary care setting. Methods In this single‐center study, we used nasopharyngeal swabs from 403 cases from the emergency department and intensive care unit of our hospital. The reference standard for detecting SARS‐CoV‐2 was the reverse‐transcription polymerase chain reaction (RT‐PCR) assay. Cycle threshold (Ct) values were recorded for positive RT‐PCR assays. The index test was the Elecsys SARS‐CoV‐2 antigen assay. This electrochemiluminescence immunoassay produces results as cutoff index (COI) values, with values ≥1.00 being reported as positive. Results Of the 403 cases, 47 showed positive results in RT‐PCR assays. Of the 47 RT‐PCR‐positive cases, 12 showed positive results in the antigen assay. Of the 356 RT‐PCR‐negative cases, all showed negative results in the antigen assay. Thus, the antigen assay showed a sensitivity of 26% (95% CI, 14%‐40%) and specificity of 100% (95% CI, 99%‐100%). Analysis of the relationship between Ct values and COI values in the 47 RT‐PCR‐positive cases showed a correlation coefficient of −0.704 (95% CI, −0.824 to −0.522). The true‐positive rate of the antigen assay for Ct values of 15–24.9, 25–29.9, 30–34.9, and 35–39.9 was 100%, 44%, 8%, and 6%, respectively. Conclusions The Elecsys SARS‐CoV‐2 antigen assay has a low sensitivity for detecting SARS‐CoV‐2 from nasopharyngeal swabs. Hence, we decided to not use this assay in the clinical routine of our hospital., Background: This report describes a manufacturer‐independent evaluation of the diagnostic accuracy of the Elecsys SARS‐CoV‐2 antigen assay from Roche Diagnostics in a tertiary care setting.Methods: In this single‐center study, we used nasopharyngeal swabs from 403 cases from the emergency department and intensive care unit of our hospital. The reference standard for detecting SARS‐CoV‐2 was the reverse transcription polymerase chain reaction (RT‐PCR) assay. Cycle threshold (Ct) values were recorded for positive RT‐PCR assays. The index test was the Elecsys SARS‐CoV‐2 antigen assay. This electrochemiluminescence immunoassay produces results as cutoff index (COI) values, with values ≥1.00 being reported as positive.Results: Of the 403 cases, 47 showed positive results in RT‐PCR assays. Of the 47 RT‐PCR‐positive cases, 12 showed positive results in the antigen assay. Of the 356 RT‐PCR‐negative cases, all showed negative results in the antigen assay. Thus, the antigen assay showed a sensitivity of 26% (95% CI, 14%‐40%) and specificity of 100% (95% CI, 99%‐100%). Analysis of the relationship between Ct values and COI values in the 47 RT‐PCR‐positive cases showed a correlation coefficient of −0.704 (95% CI, −0.824 to −0.522). The true‐positive rate of the antigen assay for Ct values of 15–24.9, 25–29.9, 30–34.9, and 35–39.9 was 100%, 44%, 8%, and 6%, respectively.Conclusions: The Elecsys SARS‐CoV‐2 antigen assay has a low sensitivity for detecting SARS‐CoV‐2 from nasopharyngeal swabs. Hence, we decided to not use this assay in the clinical routine of our hospital.

Longitudinal studies assessing durability of the anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) humoral immune response have generated conflicting results. This has been proposed to be due to differences in patient populations, the lack of standardized methodologies, and the use of assays that measure distinct aspects of the humoral response. SARS-CoV-2 antibodies were serially measured in sera from a cohort of 44 well-characterized convalescent plasma donors over 120 days post-COVID-19 symptom onset, utilizing eight assays, which varied according to antigen source, the detected antibody isotype, and the activity measured (i.e., binding, blocking, or neutralizing). While the majority of assays demonstrated a gradual decline in antibody titers over the course of 120 days, the two electrochemiluminescence immunoassay Roche assays (Roche Diagnostics Elecsys anti-SARS-CoV-2 [qualitative, nucleocapsid based] and Roche Diagnostics Elecsys anti-SARS-CoV-2 S [semiquantitative, spike based]), which utilize dual-antigen binding for antibody detection, demonstrated stable and/or increasing antibody titers over the study period. This study is among the first to assess longitudinal, rather than cross-sectional, SARS-CoV-2 antibody profiles among convalescent COVID-19 patients, primarily using commercially available serologic assays with Food and Drug Administration emergency use authorization. We show that SARS-CoV-2 antibody detection is dependent on the serologic method used, which has implications for future assay utilization and clinical value.

Rapid and widespread diagnostic testing is critical to providing timely patient care and reducing transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Recently, the Visby Medical COVID-19 point of care (POC) test was granted emergency use authorization (EUA) for qualitative detection of SARS-CoV-2 nucleic acid at the point of care. We evaluated its performance characteristics using residual specimens (n = 100) collected from Mayo Clinic patients using nasopharyngeal (NP) swabs and placed in viral transport media (VTM). The same specimen was tested using both the laboratory reference method (RT-qPCR) and Visby test. The reference methods utilized included a laboratory developed test with EUA (Mayo Clinic Laboratories, Rochester, MN) using the TaqMan assay on a Roche Light Cycler 480 or a commercially available EUA platform (cobas® SARS-CoV-2; Roche Diagnostics, Indianapolis, IN). Positive, negative, and overall percent agreement between the Visby COVID-19 test and the reference method were calculated. Additionally, the limit of detection (LoD) claimed by the manufacturer (1112 copies/mL) was verified with serial dilutions of heat inactivated virus. The Visby COVID-19 test correctly identified 29/30 positive samples and 69/70 negative samples, resulting in an overall concordance of 98.0%, positive percent agreement of 96.7%, and negative percent agreement of 98.6%. The abbreviated LoD experiment showed that the analytical sensitivity of the method is as low as or lower than 500 copies/mL. Our study demonstrated that Visby COVID-19 is well-suited to address rapid SARS-CoV-2 testing needs. It has high concordance with central laboratory-based RT-qPCR methods, a low rate of invalid results, and superior analytical sensitivity to some other EUA POC devices.

Rapid antigen detection (RAD) tests for the detection of SARS‐CoV‐2 are simpler, faster, and less expensive than the reverse‐transcription polymerase chain reaction (RT‐PCR) that is currently considered the gold standard for the diagnosis of coronavirus disease 2019 (COVID‐19). The objective of this study was to determine the performance of the PANBIO COVID‐19 Ag RAD (Abbott) test, a lateral flow immunoassay that detects the nucleocapsid protein, using as a reference RT‐PCR method the Cobas®8800 System (Roche Diagnostics). This prospective study was conducted in a tertiary Children's Hospital and included individuals aged ≤16 years with COVID‐19‐related symptoms or epidemiological criteria for COVID‐19. Two nasopharyngeal samples were collected to perform the PANBIO RAD test and RT‐PCR. Of 744 children included, 51 (6.86%) had a positive RT‐PCR result. The RAD test detected 42 of 51 PCR‐positive children while there were no false‐positive results. The overall sensitivity and specificity were 82.35% (95% CI, 71.9%–92.8%) and 100%, respectively. Sensitivity was >95% in symptomatic children. The assay performed poorly in asymptomatically infected children. In agreement with previous studies in adults, the PANBIO RAD test can be useful in screening for COVID‐19 in children admitted with symptoms suggestive of the disease, especially in the first days of the illness.

Objectives To determine the influence of pH on recovery of analytes in body fluids (BFs), investigate the mechanism of pH interference, measure the frequency of abnormal-pH BFs received, and compare pH measured by meter and paper. Methods We performed pH titration in residual BFs. A low-pH BF was spiked and neutralized to investigate pH interference. We measured analytes on a Roche cobas c501 analyzer (Roche Diagnostics) and calculated the percent recovery. Measurement of pH using a meter and paper was conducted on 122 BF samples received in the laboratory. Results Enzyme activity in BFs was unaffected when pH = 7.4-8.5 lactate dehydrogenase, pH = 7.3-10.2 amylase, pH = 6.0-9.9 lipase, and pH = 1.3-11.7 all other analytes. BFs had mean (range) pH of 8.0 (5.1-8.9), with a mean (range) difference (paper ‒ meter) of ‒0.4 (‒0.6 to 1.1). Conclusions Irreversible loss of enzyme activity occurs in BFs at low pH. Few clinical BFs have pH

Aim: This real-world study was aimed at establishing reference intervals (RIs) of ten commonly used clinical chemistry analytes (total cholesterol, triglycerides, Apo A1, Apo B, creatine kinase (CK), CK isoenzyme MB, glucose, alkaline phosphatase, γ-glutamyltransferase and blood urea nitrogen) in an apparently healthy population in China. Materials & methods: A total of 17,356 healthy participants aged 18–79 years who underwent check-up at MJ Health Check-up Center were included. The establishment of RIs was performed according to the Clinical and Laboratory Standards Institute EP28-A3c guideline. Roche Cobas c701 automatic analyzer (Roche Diagnostics, Mannheim, Germany) was employed to measure the concentrations of analytes. Results: Total cholesterol, triglycerides, Apo B, CK, alkaline phosphatase, glucose, γ-glutamyltransferase and blood urea nitrogen required gender and age-specific partitioning. Conclusion: The RIs established in this study were parallel to current national standards and previous RIs established in Chinese population. Real-world studies may play an important and practical role in the determination of RIs in the future.

Background Salivary detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been proposed as an alternative to nasopharyngeal or oropharyngeal swab testing. Our group previously published a study demonstrating that both testing methods identified SARS-CoV-2 using polymerase chain reaction (PCR)-based detection methodology. We therefore conducted a follow-up study using antibody testing to evaluate the accuracy of saliva versus swabs for COVID-19 detection and the durability of antibody response. Methods Venous blood samples were collected from consenting participants and the presence of serum antibodies for SARS-CoV-2 was evaluated on a large, automated immunoassay platform by the Roche anti-SARS-CoV-2 qualitative assay (Roche Diagnostics, Laval Quebec). Individuals with a serum antibody cut-off index (COI) ≥ 1.0 were considered positive. Results In asymptomatic and mildly symptomatic patients with a previously positive standard swab and/or saliva SARS-CoV-2 PCR-test, 42 demonstrated antibodies with 13 patients positive by swab alone, and 8 patients positive by saliva alone. Conclusions Despite their status as ‘current standard’ for COVID-19 testing, these findings highlight limitations of PCR-based tests.

Introduction. Clinical microbiology laboratories have had to cope with an increase in the volume of tests due to the emergence of the SARS-CoV-2 virus. Short turnaround times (TATs) are important for case tracing and to help clinicians in patient management. In such a context, high-throughput systems are essential to process the bulk of the tests. Rapid tests are also required to ensure shorter TATs for urgent situations. In our laboratory, SARS-CoV-2 assays were initially implemented on our custom platform using a previously published method. The commercial cobas 6800 (Roche diagnostics) assay and the GeneXpert Xpress (Cepheid) SARS-CoV-2 assay were implemented on 24 March and 8 April 2020, respectively, as soon as available. Hypothesis/Gap Statement. Despite the abundant literature on SARS-CoV-2 assays, the articles focus mainly on the diagnostic performances. This is to our knowledge the first article that specifically studies the TAT of different assays. Aim. We aimed to describe the impact of various SARS-CoV-2 assays on the TAT at the beginning of the outbreak. Methodology. In this study, we retrospectively analysed the TAT of all SARS-CoV-2 assays performed in our centre between 24 February and 9 June, 2020. Results. We retrieved 33 900 analyses, with a median TAT of 6.25 h. TATs were highest (6.9 h) when only our custom platform was used (24 February to 24 March, 2020). They were reduced to 6.1 h when the cobas system was introduced (24 March to 8 April, 2020). The implementation of the GeneXpert further reduced the median TAT to 4.8 h (8 April to 9 June, 2020). The GeneXpert system had the shortest median TAT (1.9 h), followed by the cobas (5.5 h) and by our custom platform (6.9 h). Conclusion. This work shows that the combination of high-throughput systems and rapid tests allows the efficient processing of a large number of tests with a short TAT. In addition, the use of a custom platform allowed the quick implementation of an in-house test when commercial assays were not yet available.

Acquired Immunodeficiency syndrome (AIDS) is an important global public health issue. Increasing HIV/AIDS cases reported each year has become a serious health problem for our country. The fourth generation enzyme immunoassay (EIA) test is the first step in the laboratory diagnosis of human immunodeficiency virus (HIV) infection. When the EIA test is repeatedly reactive, antibody-based tests such as immuno blot (IB), line immunoassay (LIA), HIV 1-2 antibody differentiation immunoassay, and HIV RNA tests for the early period of infection are used as confirmatory tests. The aim of this study was to evaluate the results of three different methods for the diagnosis of HIV infection. HIV 1-2 IB and quantitative HIV-1 RNA PCR tests were performed in 199 patient samples. These samples were detected as the reactive or gray zone with HIV 1-2 Ab+Ag EIA test between 2010 and 2015 at Akdeniz University Hospital, Microbiology Laboratory. HIV 1-2 Ab+Ag determination in serum samples was performed with the EIA method (Elecsys HIV combi PT test, Roche Diagnostics, Germany). A commercial kit (INNO-LIA HIV I-II Score, Innogenetics, Belgium) was used for HIV 1-2 IB method. The presence of HIV-1 RNA was investigated by automated nucleic acid extraction and real-time PCR method (Ampliprep/COBAS Tagman HIV-1 Test, Roche Diagnostics, Germany) in plasma samples. For statistical analysis, SPSS, Mann Whitney U test was used, ROC analysis was performed and p 10.000.000, > 10.000.000 and 5.040.000 copies/ml, respectively). For the kit that we used for HIV 1-2 Ab+Ag EIA COI ratio of >16.45 had a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 97.6%, 98.1%, 97.6% and 98.1%, respectively for the detection of HIV infection (r= 0.994, p 10.000.000, 5.040.000 and > 10.000.000 copies/ml whose EIA tests were repeatedly reactive. HIV IB test was detected as the gray zone in one of them and as negative in the remaining two (HIV EIA S/CO values were 265, 9.5 and 131.8, respectively). These patients were diagnosed as acute HIV infection with clinical and laboratory findings. In conclusion, HIV RNA should also be performed and included in the diagnostic algorithm for acute HIV infection.

Hyperlipidemia, excessive amounts of fat and fatty substances in the blood, is a major risk factor for cardiovascular disease. The measuring of fat or fatty substance in blood is usually obtained through a blood lipid test which includes total cholesterol (TC), triglycerides (TG), low-density lipoprotein (LDL) and high-density lipoprotein (HDL). In the Medical Device industry, Point-of-care (POC) methods provide fast, portable and easy to use devices suitable for rapid determination of Lipid levels. Here, we evaluated the analytical performance of PixoTest POCT Lipid System (iXensor Co., Ltd.), a newly developed POC lipid panel analyzer. PixoTest POCT Analyzer accuracy evaluation with the Cobas c111 Analyzer (Roche Diagnostics Ltd.) as a reference method was carried out according to CLSI EP 09-A3 guidelines. This study enrolled one hundred and twenty (120) subjects and conducted over three (3) clinical sites (40 subjects each), administered through nine (9) trained operators (total) performed under manufacturer’s protocol using three (3) reagent lots per blood sample (capillary & venous). Linear regression, bias plot and other statistical analyses were extrapolated from the test data in this study. Passing-Bablok regression analysis of the data between PixoTest POCT System and Roche Cobas c111 Analyzer with the venous blood showed a slope of 1.03, an intercept of − 0.1 and correlation coefficient of 0.99. The results for capillary blood showed a slope of 1.01, an intercept of − 0.04 and correlation coefficient of 0.99. Passing-Bablok regression analysis of the data (n = 120) from the comparison between the PixoTest POCT System and Roche Cobas c111 Analyzer with the TC venous blood of total 3 lots at 3 sites showed a slope of 0.99, an intercept of − 0.337 and correlation coefficient of 0.995 and the TC capillary blood showed a slope of 0.99, an intercept of − 0.105 and correlation coefficient of 0.984. TG venous blood of total 3 lots at 3 sites showed a slope of 0.99, an intercept of 0.0246 and correlation coefficient of 0.998 and TG capillary blood showed a slope of 0.99, an intercept of − 0.329 and correlation coefficient of 0.998. HDL venous blood showed a slope of 0.99, an intercept of − 0.0297 and correlation coefficient of 0.987 and the HDL capillary blood showed a slope of 0.99, an intercept of − 0.0403 and correlation coefficient of 0.989. The evaluation results of PixoTest POCT system’s accuracy, linearity, and correlation with Roche Cobas c111 Analyzer, the PixoTest POCT System displayed great performance results for all evaluated data points. Thus, the PixoTest POCT System is capable of providing accurate and reliable lipid measurements in the POC setting.

Aim To describe quality management processes and appropriate interpretation with respect to HbA1c point-of-care (POC) testing in a national diabetes and cardiovascular risk screening programme. Methods We compared HbA1c results from capillary blood, measured by the cobas b 101 (Roche Diagnostics) POC testing system, with results from venous blood measured by accredited laboratory analysers to inform national screening practice and a (separately-reported) randomised controlled trial. Difference plots and regressions were used to aid interpretation around 40 and 50 mmol/mol, the cut-offs used to identify “pre-diabetes” and diabetes in New Zealand. Results After initial acceptable tests, subsequent batches delivered POC results that varied from laboratory HbA1c by +6 to −14 mmol/mol around the clinical cut-offs. Ten faulty batches of discs were recalled worldwide. POC testing was suspended in one region, as was the planned trial. The manufacturing defect was rectified, accuracy of the new batches was confirmed, and testing resumed. Conclusion POC testing must be conducted within stringent quality assurance processes prior to and while in use. Within such a system, POC testing for HbA1c can be sufficiently accurate for screening and diagnosis of diabetes.

Background Accurate, rapid, and cost-effective screening tests for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection may be useful in laboratories that cannot afford automated chemiluminescent immunoassays (CLIAs). We evaluated the diagnostic performance of a novel rapid automated fluorescent lateral flow immunoassay (LFIA). Methods A fluorescent LFIA using a small bench-top fluorescence reader, Automated Fluorescent Immunoassay System (AFIAS; Boditech Med Inc., Chuncheon, Korea), was developed for qualitative detection of hepatitis B surface antigen (HBsAg), antibody to HBsAg (anti-HBs), and antibody to HCV (anti-HCV) within 20 minutes. We compared the diagnostic performance of AFIAS with that of automated CLIAs—Elecsys (Roche Diagnostics GmbH, Penzberg, Germany) and ARCHITECT (Abbott Laboratories, Abbott Park, IL, USA)—using 20 seroconversion panels and 3,500 clinical serum samples. Results Evaluation with the seroconversion panels demonstrated that AFIAS had adequate sensitivity for HBsAg and anti-HCV detection. From the clinical samples, AFIAS sensitivity and specificity were 99.8% and 99.3% for the HBsAg test, 100.0% and 100.0% for the anti-HBs test, and 98.8% and 99.1% for the anti-HCV test, respectively. Its agreement rates with the Elecsys HBsAg, anti-HBs, and anti-HCV detection assays were 99.4%, 100.0%, and 99.0%, respectively. AFIAS detected all samples with HBsAg genotypes A-F and H and anti-HCV genotypes 1, 1a, 1b, 2a, 2b, 4, and 6. Cross-reactivity with other infections was not observed. Conclusions The AFIAS HBsAg, anti-HBs, and anti-HCV tests demonstrated diagnostic performance equivalent to current automated CLIAs. AFIAS could be used for a large-scale HBV or HCV screening in low-resource laboratories or low-to middle-income areas.

Background: Mass testing for early identification and isolation of infectious COVID-19 individuals is efficacious for reducing disease spread. Antigen-detecting rapid diagnostic tests (Ag-RDT) may be suitable for testing strategies; however, benchmark comparisons are scarce. Methods: We used 286 nasopharyngeal specimens from unexposed asymptomatic individuals collected between December 2020 and January 2021 to assess five Ag-RDTs marketed by Abbott, Siemens, Roche Diagnostics, Lepu Medical, and Surescreen. Results: For the overall sample, the performance parameters of Ag-RDTs were as follows: Abbott assay, sensitivity 38.6% (95%CI 29.1-48.8) and specificity 99.5% (97-100%); Siemens, sensitivity 51.5% (41.3-61.6) and specificity 98.4% (95.3-99.6); Roche, sensitivity 43.6% (33.7-53.8) and specificity 96.2% (92.4-98.5); Lepu, sensitivity 45.5% (35.6-55.8) and specificity 89.2% (83.8-93.3%); Surescreen, sensitivity 28.8% (20.2-38.6) and specificity 97.8% (94.5-99.4%). For specimens with cycle threshold (Ct) = 70%. The modelled negative- and positive-predictive value for 1% prevalence were >99% and 80% for specimens with Ct= 96%. The estimated negative predictive value suggests the suitability of Ag-RDTs for mass screenings of SARS-CoV-2 infection in the general population. (C) 2021 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

The performance of a laboratory-developed quantitative IgG/IgA flow cytometry-based immunoassay (FCI) using Jurkat T cells stably expressing full-length native S protein was compared against Elecsys® electrochemiluminiscent (ECLIA) Anti-SARS-CoV-2 S (Roche Diagnostics, Pleasanton, CA, USA), and LIAISON® SARS-CoV-2 TrimericS IgG chemiluminiscent assay (CLIA) (Diasorin S.p.a, Saluggia, IT) for detection and quantitation of SARS-CoV-2-specific antibodies. A total of 225 serum/plasma specimens from 120 acute or convalescent COVID-19 individuals were included. Overall, IgG/IgA-FCI yielded the highest number of positives (n=179), followed by IgA-FCI (n=177), Roche ECLIA (n=175), IgG-FCI (n=172) and Diasorin CLIA (n=154). Positive percent agreement between FCI and compared immunoassays was highest for Roche ECLIA, ranging from 96.1% (IgG/IgA-FCI) to 97.7% (IgG-FCI), whereas negative percent agreement was higher between FCI and Diasosin CLIA, regardless of antibody isotype. A strong correlation (Rho:0.6-0.8) was found between IgG-FCI or IgA-FCI levels and antibodies quantified by Roche ECLIA and Diasorin CLIA. The trajectory of antibody levels delineated by the different immunoassays in 22 of patients with sequential specimens (≥3) was frequently discordant, with the exception of IgG and IgA determined by FCI assay and to a lesser extent antibodies quantified by Roche ECLIA and Diasorin CLIA. The data suggest that FCI may outperform Roche ECLIA and Diasorin CLIA in terms of clinical sensitivity for serological diagnosis of SARS-CoV-2 infection.

Objectives Thyroid hormone analog 3,5,3'-triiodothyroacetic acid (TRIAC) is effective in reducing the hypermetabolism in monocarboxylate transporter 8 (MCT8)–deficient individuals. Because of the structural similarity between TRIAC and 3,3',5'-triiodothyronine (T3), we sought to investigate the degree of cross-reactivity of TRIAC with various commercially available total and free T3 assays. Methods Varying concentrations (50-1,000 ng/dL) of TRIAC (Sigma Aldrich) were added to pooled serum and assayed for total T3 (TT3) and free T3 (FT3) on the following platforms: e602 (Roche Diagnostics), Architect (Abbott Diagnostics), Centaur (Siemens Healthcare Diagnostics), IMMULITE (Siemens Healthcare Diagnostics), DxI (Beckman Coulter), and Vitros (Ortho Clinical Diagnostics). TT3 competition assay with TRIAC was performed by adding increasing amounts of T3 to pooled serum samples that contained a constant concentration of TRIAC (250 ng/dL). Results Significant overestimation of TT3 and FT3 assays were observed across all platforms corresponding to increasing concentrations of TRIAC. The TRIAC effect at 250 ng/dL showed a constant interference of approximately 190 ng/dL TT3. Conclusions All commercial TT3 and FT3 assays tested in this work cross-react significantly with TRIAC. Therefore, patients undergoing TRIAC therapy should have T3 hormone response monitored using alternative nonimmunoassay-based methods to avoid misinterpretation of thyroid function profiles.

Objectives A newly developed fully automated Lumipulse G AMH method (Fujirebio Diagnostics) was recently introduced in clinical laboratories for quantitative determination of anti-Mullerian hormone (AMH) level in human serum or plasma. AMH has emerged as value-added biomarker in the assessment of ovarian reserve, in diagnosis of granulosa cells cancer and in the investigation of gonadal disorders. We compared Lumipulse G AMH assay performances with other methods largely applied for AMH measurements. Design and Methods The Lumipulse G AMH method based on two-step sandwich chemiluminescence enzyme immunoassay was assessed on Lumipulse G600II analyzer. The evaluation study included imprecisions, sensitivity and linearity whereas a comparison study was performed on a heterogeneous population of 114 patients by using the Elecsys AMH Plus assay on COBAS 8000 e602 module (Roche Diagnostics). Results Lumipulse G AMH system showed good repeatability (within-run imprecision) with CV values below 1% (0.5% and 0.9% for high and low serum pools). Similarly within-laboratory imprecision was assessed with CV values of 2.5% and 1.6% for high and low level controls respectively. A linearity regression formula of 1.0119x-0.067 with a coefficient of determination (r2) equal to 0.999 was obtained in a range from 0.044 to 22.42 ​ng/ml. Passing-Bablok regression analysis was performed for assay comparability of AMH measurements. Results were closely correlated (correlation coefficient ​= ​0.997) with a regression equation (y ​= ​1.230x-0.025) showing a positive slope. Also, Bland-Altman analysis confirmed a good agreement between Lumipulse G AMH and Roche Elecsys AMH Plus assays with a bias of 17.76% in a large measurement range. Conclusions The performance of Lumipulse G AMH system was highly comparable with that of Roche Elecsys AMH Plus assay although approximately 10% higher values of AMH levels were observed for Lumipulse AMH system at all range of concentrations. Nevertheless the Lumipulse G system seems to be largely suitable for quantitative determination of AMH level in small-scale laboratory because of the reduced size and the use of single cartridge per test assuring flexibility and easy handling.

High-sensitivity cardiac troponin (hs-cTn) assays have different analytic characteristics.The goal of this study was to quantify differences between assays for common analytical benchmarks and to determine whether they may result in differences in the management of patients with suspected acute coronary syndrome (ACS).The authors included patients with suspected ACS enrolled in the ROMICAT (Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography) I and II trials, with blood samples taken at emergency department presentation (ROMICAT-I and -II) or at 2 and 4 h thereafter (ROMICAT-II). hs-cTn concentrations were measured using 3 assays (Roche Diagnostics, Elecsys 2010 platform; Abbott Diagnostics, ARCHITECT i2000SR; Siemens Diagnostics, HsVista). Per blood sample, we determined concordance across analytic benchmarks (limit of detection [LOD]/LOD-99th percentile/99th percentile). Per-patient, the authors determined concordance of management recommendations (rule-out/observe/rule-in) per the 0/2-h algorithm, and their association with diagnostic test findings (coronary artery stenosis50% on coronary computed tomography angiography or inducible ischemia on perfusion imaging) and ACS.Among 1,027 samples from 624 patients (52.8 ± 10.0 years; 39.4% women), samples were classified as LOD (56.3% vs. 10.4% vs. 41.2%; p 0.001), LOD-99th percentile (36.5% vs. 83.5% vs. 52.6; p 0.001),99th percentile (7.2% vs. 6.0% vs. 6.2%) by Roche, Abbott, and Siemens, respectively. A total of 37.4% (n = 384 of 1,027) of blood samples were classified into the same analytical benchmark category, with low concordance across benchmarks (LOD 11.1%; LOD-99th percentile 29.3%;99th percentile 43.6%). Serial samples were available in 242 patients (40.1% women; mean age: 52.8 ± 8.0 years). The concordance of management recommendations across assays was 74.8% (n = 181 of 242) considering serial hs-cTn measurements. Of patients who were recommended to discharge, 19.6% to 21.1% had positive diagnostic test findings and 2.8% to 4.3% had ACS at presentation.Caregivers should be aware that there are significant differences between hs-cTn assays in stratifying individual samples and patients with intermediate likelihood of ACS according to analytical benchmarks that may result in different management recommendations. (Rule Out Myocardial Infarction by Computer Assisted Tomography [ROMICAT]; NCT00990262) (Multicenter Study to Rule Out Myocardial Infarction by Cardiac Computed Tomography [ROMICAT-II]; NCT01084239).

Background: Our objective was to determine the effect of therapeutic concentrations of N-acetylcysteine, following intravenous infusion, on the measurement of blood glucose using a Roche Diagnostics glucose dehydrogenase-linked glucose meter compared to hospital laboratory methods. Methods: N-acetylcysteine was added to aliquots of blood, with glucose promptly measured by the glucose meter, blood gas analyzer (glucose oxidase comparative method) and following centrifugation, plasma glucose measured with a hexokinase spectrophotometric comparative method. Glucose results were evaluated with linear regression and Bland Altman plots. Results: In the presence of NAC, at concentrations greater than 5 mg/dL (0.31 mmol/L), positively biased glucose meter results were compared to the clinical laboratory results. Multivariate linear regression revealed that NAC-mediated meter results are influenced by NAC and glucose concentrations. Conclusions: The addition of therapeutic concentrations of NAC to blood produces statistically significant positive biases when measured with the glucose dehydrogenase linked glucose meter device.

Objectives The Pfizer-BioNTech BNT162b2 vaccine against SARS-CoV-2 infection is now available. This vaccine induces antibody production against the receptor-binding domain (RBD) of the spike glycoprotein S1 (S1-RBD). This study evaluated the performance of new immunoassays to measure this type of antibody. Methods Blood samples were collected at t0 (prime dose), after 21 days (t1, booster dose), and then after another 15 days (t2) from 70 health care professionals who had tested negative for previous SARS-CoV-2 infection and underwent vaccination with BNT162b2. Results Antibodies against S1-RBD were measured using 4 commercial assays. At t0, t1, and t2, the median antibody concentrations (interquartile range) were, respectively, 0.2 (0.1-0.4), 49.5 (19.1-95.7), and 888.0 (603.6-1,345.8) U/mL by Maglumi SARS-CoV-2 S-RBD immunoglobulin G (IgG) (Shenzen New Industries Biomedical Engineering, Snibe Diagnostics); 0.0 (0.0-0.0), 7.9 (4.2-15.6), and 112.3 (76.4-205.6) U/mL by Atellica IM SARS-CoV-2 IgG assay (Siemens Healthineers); 0.0 (0.0-0.0), 59.9 (18.3-122.0), and 2,646.0 (1,351.2-4,124.0) U/mL by Elecsys Anti–SARS-CoV-2 S assay (Roche Diagnostics); and 1.8 (1.8-1.8), 184 (94-294), and 1,841.0 (1,080.0-2,900.0) AU/mL by LIAISON SARS-CoV-2 TrimericS IgG assay (DiaSorin). The differences between medians at t0, t1, and t2 were all statistically significant (P < .001). Conclusions Antibodies against nucleocapsid proteins (N) were also measured using Maglumi 2019-nCoV IgG assay, which showed all negative results. All the considered anti-RBD methods detected response to the vaccine, while the method directed against anti-N failed to show response.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). While molecular-based testing is used to diagnose COVID-19, serologic testing of antibodies specific to SARS-CoV-2 is used to detect past infection., The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). Molecular-based testing is used to diagnose COVID-19, and serologic testing of antibodies specific to SARS-CoV-2 is used to detect past infection. While most serologic assays are qualitative, a quantitative serologic assay was recently developed that measures antibodies against the S protein, the target of vaccines. Quantitative antibody determination may help determine antibody titer and facilitate longitudinal monitoring of the antibody response, including antibody response to vaccines. We evaluated the quantitative Roche Elecsys anti-SARS-CoV-2 S assay. Specimens from 167 PCR-positive patients and 103 control specimens were analyzed using the Elecsys anti-SARS-CoV-2 S assay on the cobas e411 (Roche Diagnostics). Analytical evaluation included assessing linearity, imprecision, and analytical sensitivity. Clinical evaluation included assessing clinical sensitivity, specificity, cross-reactivity, positive predictive value (PPV), negative predictive value (NPV), and serial sampling from the same patient. The Elecsys anti-SARS-CoV-2 S assay exhibited its highest sensitivity (84.0%) at 15 to 30 days post-PCR positivity and exhibited no cross-reactivity, a specificity and PPV of 100%, and an NPV between 98.3% and 99.8% at ≥14 days post-PCR positivity, depending on the seroprevalence estimate. Imprecision was