No abstract

No abstract

Due to globally rising numbers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, resources for real-time reverse-transcription polymerase chain reaction (rRT-PCR)-based testing have been exhausted. In order to meet the demands of testing and reduce transmission, SARS-CoV-2 antigen-detecting rapid diagnostic tests (Ag-RDTs) are being considered. These tests are fast, inexpensive, and simple to use, but whether they detect potentially infectious cases has not been well studied. We evaluated three lateral flow assays (RIDA®QUICK SARS-CoV-2 Antigen (R-Biopharm), SARS-CoV-2 Rapid Antigen Test (Roche)), and NADAL® COVID-19 Ag Test (Nal von Minden GmbH, Regensburg, Germany) and one microfluidic immunofluorescence assay (SARS-CoV-2 Ag Test (LumiraDx GmbH, Cologne, Germany)) using 100 clinical samples. Diagnostic rRT-PCR and cell culture testing as a marker for infectivity were performed in parallel. The overall Ag-RDT sensitivity for rRT-PCR-positive samples ranged from 24.3% to 50%. However, for samples with a viral load of more than 6 log10 RNA copies/mL (22/100), typically seen in infectious individuals, Ag-RDT positivity was between 81.8% and 100%. Only 51.6% (33/64) of the rRT-PCR-positive samples were infectious in cell culture. In contrast, three Ag-RDTs demonstrated a more significant correlation with cell culture infectivity (61.8–82.4%). Our findings suggest that large-scale SARS-CoV-2 Ag-RDT-based testing can be considered for detecting potentially infective individuals and reducing the virus spread.

No abstract

Vitamin D is an important immune modulator that plays an emerging role in inflammatory and metabolic liver diseases, including infection with hepatitis C virus (HCV). In contrast, the relationship between vitamin D metabolism and chronic hepatitis B (CHB) is less well characterized. Therefore, we quantified 25(OH)D 3 serum levels in a cohort of 203 treatmentna€ ıve patients with chronic hepatitis B virus (HBV) infection and tested for their association with clinical parameters of CHB. Of 203 patients, 69 (34%), 95 (47%), and 39 (19%) had severe vitamin D deficiency (25(OH)D 3 <10 ng/mL), vitamin D insufficiency (25(OH)D 3 10 and <20 ng/mL), or adequate vitamin D serum levels (25(OH)D 3 20 ng/mL), respectively. In both uni-and multivariate analyses, HBV DNA viral load (log 10 IU/mL) was a strong predictor of low 25(OH)D 3 serum levels (P 5 0.0007 and P 5 0.000048, respectively) and vice versa. Mean 25(OH)D 3 serum concentrations in patients with HBV DNA <2,000 versus 2,000 IU/mL were 17 versus 11 ng/mL, respectively (P < 0.00001). In addition, hepatitis B early antigen (HBeAg)-positive patients had lower 25(OH)D 3 serum levels than HBeAg-negative patients (P 5 0.0013). Finally, 25(OH)D 3 and HBV DNA serum levels showed inverse seasonal fluctuations. Conclusion: Low 25(OH)D 3 serum levels are associated with high levels of HBV replication in patients with CHB. This represents a major difference from chronic hepatitis C, where numerous previous studies have shown a lack of correlation between HCV viral load and vitamin D serum levels. Inverse seasonal fluctuations of 25(OH)D 3 and HBV DNA serum levels are suggestive of a functional relationship between both variables. (HEPATOLOGY 2013;58:1270-1276

The novel coronavirus SARS-CoV-2 is the causative agent of the acute respiratory disease COVID-19, which has become a global concern due to its rapid spread. Meanwhile, increased demand for testing has led to a shortage of reagents and supplies and compromised the performance of diagnostic laboratories in many countries. Both the World Health Organization (WHO) and the Center for Disease Control and Prevention (CDC) recommend multi-step RT-PCR assays using multiple primer and probe pairs, which might complicate the interpretation of the test results, especially for borderline cases. In this study, we describe an alternative RT-PCR approach for the detection of SARS-CoV-2 RNA that can be used for the probe-based detection of clinical isolates in diagnostics as well as in research labs using a low-cost SYBR green method. For the evaluation, we used samples from patients with confirmed SARS-CoV-2 infections and performed RT-PCR assays along with successive dilutions of RNA standards to determine the limit of detection. We identified an M-gene binding primer and probe pair highly suitable for the quantitative detection of SARS-CoV-2 RNA for diagnostic and research purposes.

miR-122 is a liver-specific microRNA, which also circulates in the blood. The levels of miR-122 in serum and plasma correlate with hepatic necroinflammation in patients with hepatitis B virus (HBV) infection. Here, we investigated whether miR-122 levels correlate with surrogate markers for viral replication and translation. Furthermore, we examined whether miR-122 levels differ in the different groups of HBV-infected patients and whether miR-122 levels may be useful to identify patients with higher or lower risk for liver disease progression. Therefore, RNA was extracted from sera of therapy-naïve patients with HBV infection (n = 89) and from healthy volunteers (n = 19). The concentration of miR-122 was assessed by quantitative real-time reverse-transcription PCR. HBs antigen and HBV DNA levels were quantified as surrogate parameters for HBV replication and translation. Liver biopsies were examined according to the histological activity index and the degree of fibrosis was assessed. We found that the miR-122 serum concentration correlated with the level of ALT, HBV DNA and HBs antigen (r = 0.259, P < 0.05; r = 0.225, P < 0.05; r = 0.508, P < 0.001, respectively). The miR-122 serum levels discriminated the different patient groups infected with HBV from healthy subjects (P < 0.001), and inactive carrier patients with high (>3500 IU/mL) or low (<3500 IU/mL) levels of HBs antigen could be differentiated by the miR-122 serum concentration (P < 0.05). As serum miR-122 levels strongly correlated with HBs antigen, it might be an indicator for viral translation. Furthermore, serum miR-122 levels discriminated HBV carrier patients with high or low risk for disease progression and may, thus, be an additional marker for risk stratification.

Isolated reactivity to hepatitis B virus (HBV) core antigen (anti-HBc) is observed relatively frequently in immunocompromised individuals, intravenous drug abusers (IVDA), and in the presence of HCV infection. The reason for the lack of HBsAg is not clear. The aim of the present study was to investigate which factors (genetic variability of S gene, low-level HBsAg, and immune complexes may be responsible for the failure of HBsAg detection with commercial HBsAg screening assays. Dilution series of two recombinant HBsAg escape mutants and dilutions of serum samples from chronic HBV carriers with multiple insertions in the a determinant and different HBsAg subtypes were tested with a highly sensitive assay that detects wild-type HBsAg (Elecsys HBsAg, Roche Diagnostics, Penzberg, Germany) and two assays that detect HBV wild-type and escape mutants (Murex HBsAg Version 3, Murex and Enzygnost HBsAg 5.0, Dade Behring, Marburg, Germany). Elecsys HBsAg showed in comparison to Murex HBsAg Version 3 and Enzygnost HBsAg 5.0 a reduced sensitivity for escape mutant detection. On the other hand, the best performance for HBsAg subtype detection was obtained with Elecsys HBsAg. In the second part of the study, a selected panel of isolated anti-HBc reactive (n = 104) serum samples (AxSYM Core) was submitted to testing by Elecsys HBsAg, Murex HBsAg Version 3, Enzygnost HBsAg 5.0, and HBsAg detection after immune complex dissociation (ICD) and anti-HBs determination with two different assays (AxSYM Ausab and Elecsys Anti-HBs). To assess the specificity of anti-HBc test results, all the samples were tested by a second anti-HBc assay (Elecsys Anti-HBc). Quantitative HBV DNA detection was undertaken with a commercially available HBV PCR assay (Amplicor HBV Monitor). HCV infection was present in 65.4% of anti-HBc only reactive individuals. Five AxSYM Core positive samples were negative by Elecsys Anti-HBc. Overall, 15 (14.4%) AxSYM Ausab negative samples gave positive results with Elecsys Anti-HBs (median value: 21 IU/ml). No low-level HBsAg carrier was detected among the isolated anti-HBc reactive individuals with Elecsys HBsAg. There was no evidence for the presence of immune complexes. Only one sample was repeatedly reactive by the Murex HBsAg, suggesting that the a mutant form of HBsAg was responsible for the isolated anti-HBc reactivity, however neutralisation assay was not interpretable and HBV DNA PCR was negative. Fifteen (14.4%) anti-HBc only positive individuals were HBV DNA carriers with concentrations ranging from 800 to more than >4,000,000 copies of viral DNA/ml. In conclusion, the most probable explanations for isolated anti-HBc reactivity in our study group are a possible interference of HBsAg synthesis by HCV infection (65.4%) and divergence of results of anti-HBs assays (14.4%). There is no evidence for the presence of low-level HBsAg carriers and immune complexes. HBsAg mutants cannot be excluded definitively by the test strategy used in the present evaluation.