Alternative detection of SARS-CoV-2 RNA by a new assay based on mass spectrometry.

OBJECTIVES: Accurate detection of SARS-CoV-2 RNA is essential to stopping the spread of SARS-CoV-2. The aim of this study was to evaluate the performance of the recently introduced MassARRAY® SARS-CoV-2 Panel and to compare it to the cobas® SARS-CoV-2 Test. METHODS: The MassARRAY® SARS-CoV-2 Panel consists of five assays targeting different sequences of the SARS-CoV-2 genome. Accuracy was determined using national and international proficiency panels including 27 samples. For clinical evaluation, 101 residual clinical samples were analyzed and results compared. Samples had been tested for SARS-CoV-2 RNA with the cobas® SARS-CoV-2 Test. RESULTS: When accuracy was tested with the MassARRAY® SARS-CoV-2 Panel, 25 of 27 (92.6%) samples revealed correct results. When clinical samples were analyzed with the MassARRAY® SARS-CoV-2 Panel and compared to the cobas® SARS-CoV-2 Test, 100 samples showed concordant results. One sample was found to be inconclusive with the MassARRAY® SARS-CoV-2 Panel. When time-to-results were compared, the new assay showed longer total and hands-on times. CONCLUSIONS: The MassARRAY® SARS-CoV-2 Panel showed a good performance and proved to be suitable for use in the routine diagnostic laboratory. Especially during phases of shortage of reagents and/or disposables, the new test system appears as beneficial alternative to standard assays used for detection of SARS-CoV-2 RNA.

Combined testing of copeptin and high-sensitivity cardiac troponin T at presentation in comparison to other algorithms for rapid rule-out of acute myocardial infarction.

BACKGROUND: We aimed to directly compare the diagnostic and prognostic performance of a dual maker strategy (DMS) with combined testing of copeptin and high-sensitivity (hs) cardiac troponin T (cTnT) at time of presentation with other algorithms for rapid rule-out of acute myocardial infarction (AMI). METHODS: 922 patients presenting to the emergency department with suspected AMI and available baseline copeptin measurements qualified for the present TRAPID-AMI substudy. Diagnostic measures using the DMS (copeptin <10, <14 or < 20 pmol/L and hs-cTnT≤14 ng/L), the 1 h-algorithm (hs-cTnT<12 ng/L and change <3 ng/L at 1 h), as well as the hs-cTnT limit-of-blank (LoB, <3 ng/L) and -detection (LoD, <5 ng/L) were compared. Outcomes were assessed as combined end-points of death and myocardial re-infarction. RESULTS: True-negative rule-out using the DMS could be achieved in 50.9%-62.3% of all patients compared to 35.0%, 45.3% and 64.5% using LoB, LoD or the 1 h-algorithm, respectively. The DMS showed NPVs of 98.1%-98.3% compared to 99.2% for the 1 h-algorithm, 99.4% for the LoB and 99.3% for the LoD. Sensitivities were 93.5%-94.8%, as well as 96.8%, 98.7% and 98.1%, respectively. Addition of clinical low-risk criteria such as a HEART-score ≤ 3 to the DMS resulted in NPVs and sensitivities of 100% with a true-negative rule-out to 33.8%-41.6%. Rates of the combined end-point of death/MI within 30 days ranged between 0.2% and 0.3% for all fast-rule-out protocols. CONCLUSION: Depending on the applied copeptin cut-off and addition of clinical low-risk criteria, the DMS might be an alternative to the hs-cTn-only-based algorithms for rapid AMI rule-out with comparable diagnostic measures and outcomes.

Interference of the new oral anticoagulant dabigatran with frequently used coagulation tests.

BACKGROUND: Dabigatran etexilate is a new oral anticoagulant for the therapy and prophylaxis of venous thromboembolism and stroke prevention in patients with atrial fibrillation. To investigate the extent of interactions of this new anticoagulant with frequently used coagulation assays, we completed a multicenter in vitro trial with Conformité Européenne(CE)-labeled dabigatran-spiked plasma samples. METHODS: Lyophilized plasma samples with dabigatran concentrations ranging from 0.00 to 0.48 µg/mL were sent to the coagulation laboratories of six major Austrian hospitals for evaluation. Coagulation assays were performed under routine conditions using standard reagents and analyzer. RESULTS: Dabigatran led to a dose-dependent prolongation of the clotting times in coagulometric tests and influenced the majority of the parameters measured. Statistically significant interference could be observed with the prothrombin time (PT), activated partial thromboplastin time (aPTT) and PT/aPTT-based assays (extrinsic/intrinsic factors, APC-resistance test) as well as lupus anticoagulant testing. Even non-clotting tests, such as the colorimetric factor XIII activity assay and to a minor extent the amidolytic antithrombin activity assay (via factor IIa) were affected. CONCLUSIONS: This multicenter trial confirms and also adds to existing data, demonstrating that laboratories should expect to observe strong interferences of coagulation tests with increasing concentrations of dabigatran. This finding might become particularly important in the elderly and in patients with renal impairment as well as patients whose blood is drawn at peak levels of dabigatran.

A web based application for surveillance and quality management in chronic Hepatitis C.

Nearly 130 millions of people around the world are affected by chronic virus Hepatitis C infection. We have developed a web-based application for epidemiological surveillance and quality management in chronic Hepatitis C. Functionality offered by the system includes data collection and execution of predefined queries relevant in quality management. Application is available at www.healthgate.at.

No evidence of hepatitis B virus activity in patients with anti-HBc antibody positivity with or without anti-hepatitis C virus antibody positivity.

BACKGROUND: The serological pattern of anti-HBc antibody positivity without both, HBsAg and anti-HBs antibody positivity may be present in up to 4% of the population of Europe and the United States. OBJECTIVES: The aim of the present study was to determine the hepatitis B virus (HBV) activity by detection of serum HBV DNA in patients with anti-HBc antibody positivity only and with confirmed anti-hepatitis C virus (anti-HCV) antibody positivity or without anti-HCV antibody positivity. STUDY DESIGN: A total of 141 patients positive for anti-HBc antibodies only, were investigated on serum HBV DNA load. Patients were classified into two groups: patients with confirmed positive anti-HCV antibodies (group 1) and patients without anti-HCV antibodies (group 2). RESULTS: Demographic data of patient groups were similar. In 66 of 70 patients with anti-HBc antibodies and anti-HCV antibodies (group 1), serum HCV RNA was detected; the remaining 4 patients were HCV RNA negative but the presence of anti-HCV antibodies was confirmed by the line probe assay. In none of the patients, with anti-HBc antibodies and without anti-HCV antibodies (group 2), serum HCV RNA was detected. In none of the patients, serum HBV DNA was detected. CONCLUSION: In this study, serum HBV DNA could not be detected in patients with anti-HBc antibodies only. There seems to be no need for determination of serum HBV DNA in patients without clinical evidence of chronic liver disease. Nevertheless, it would be useful to test patients with progressive liver disease and those, which belong to high-risk groups such as hemophiliacs, intravenous drug abusers, patients on hemodialysis, and immunocompromised patients.

Genotyping of hepatitis C virus-comparison of three assays.

BACKGROUND: Genotyping of hepatitis C virus (HCV) is clinically relevant to epidemiology, prognosis, and therapeutical management of HCV infection. OBJECTIVES: Accuracy and specificity of three assays for HCV genotyping/subtyping were determined. The TruGene HCV 5'NC Genotyping Kit (TruGene), which is a direct sequencing test and two assays based on reversed hybridization, Inno-LiPA HCV II assay and ViennaLab HCV Strip Assay, were compared. Amplification products generated by the Cobas Amplicor HCV Test were used. STUDY DESIGN: A total of 100 consecutive HCV RNA positive samples derived from patients with chronic hepatitis C were examined for their genotypes/subtypes by the three assays. RESULTS: Identification of genotypes and subtypes by the TruGene assay as reference test for the Inno-LiPA HCV II assay and the ViennaLab HCV Strip Assay or Inno-LiPA HCV II assay as reference test for the TruGene and the ViennaLab HCV Strip Assay showed similar results for overall accuracies (TruGene as reference test for Inno-LiPA HCV II and ViennaLab HCV Strip Assay, genotypes/subtypes: 100%/95.5% and 97%/92%; Inno-LiPA HCV II as reference test for TruGene and ViennaLab HCV Strip Assay, genotypes/subtypes: 99%/85.9% and 97%/87.9%) and specificities (TruGene as reference test for Inno-LiPA HCV II and ViennaLab HCV Strip Assay, genotypes/subtypes: 100%/97.8% and 99%/97.7%; Inno-LiPA HCV II as reference test for TruGene and ViennaLab HCV Strip Assay, genotypes/subtypes: 100%/99.4% and 99.7%/98%). CONCLUSIONS: The three assays were found to be reliable for the detection and discrimination of all HCV genotypes common in Europe and in North America and to be suitable for the routine diagnostic laboratory.

Hepatitis B virus activity in patients with anti-hepatitis C virus antibody positivity and hepatitis B antigen positivity.

BACKGROUND: Co-infection with hepatitis B virus (HBV) and HCV seems to be relatively frequent. There might be a mutual influence on replication activity of HBV and HCV. OBJECTIVES: To determine the HBV activity in patients with serum HCV RNA and HBsAg positivity and in those with confirmed anti-HCV antibody and HBsAg positivity but serum HCV RNA negativity. STUDY DESIGN: A total of 1,200 anti-HCV antibody positive samples were investigated. Samples of HCV RNA and HBsAg positive patients were compared with those of confirmed anti-HCV and HBsAg positive but serum HCV RNA negative patients. HBV activity was tested with the quantitative Cobas Amplicor HBV Monitor Test (Roche Diagnostic Systems, Pleasanton, CA). RESULTS: Of all studied patients with chronic hepatitis C (serum HCV RNA positivity) only 1.0% were found to be HBsAg positive. In contrast, of all patients with confirmed anti-HCV positivity but serum HCV RNA negativity, 11.9% tested HBsAg positive. The median of HBV DNA levels of patients with serum HCV RNA positivity and HBeAg seroconversion (4.0 x 10(2) HBV DNA copies per ml) was found to be slightly lower than that of patients with serum HCV RNA negativity and HBeAg seroconversion (2.5 x 10(3) HBV DNA copies per ml; P>0.05). The median of HBV DNA levels of patients with serum HCV RNA positivity but without HBeAg seroconversion (1.1 x 10(4) HBV DNA copies per ml) was found to be significantly lower than that of patients with serum HCV RNA negativity but without HBeAg seroconversion (2.6 x 10(7) HBV DNA copies per ml; P<0.05). CONCLUSION: A mutual effect on HBV and HCV replication could be observed. The molecular assay for quantification of serum HBV DNA was found to be useful for the routine diagnostic laboratory.