Update on hepatitis B and C virus diagnosis

Hepatitis C virus core antigen assay: an alternative method for hepatitis C diagnosis

Background The study aimed to evaluate a fully automated chemiluminescent immunoassay and compared it with a quantitative RNA assay and anti-HCV assay to verify the utility of this automated Ag assay as an alternative method for hepatitis C diagnosis. Methods A total of 229 serum samples previously tested for anti-HCV concentrations by the Architect Anti-HCV assay, were selected for HCV RNA testing by real time RT-PCR kit (Shanghai ZJ Bio-Tec Co., Ltd) and 125 specimens were tested for HCV Ag by the Architect HCV core Antigen kit. Results The log₁₀ HCVAg and HCV RNA concentrations were highly correlated [ r = 0.834); with HCV RNA as the comparator test, HCVAg had 100% specificity, 100% positive predictive value (PPV) and 94.8% sensitivity. We found 1 pg/mL of total HCV core Ag is equivalent to approximately 6607HCV RNA international units (IU)/mL. Receiver operator characteristic curve analysis showed that the area under the curve of HCV core Ag (0.989) was greater than HCV Ab (0.871). HCV Ag concentrations and RNA-to-Ag ratio of the groups for HCV RNA concentrations ≤10⁵ and >10⁵IU/mL were both significantly different from each other ( P < 0.05). Conclusion The Architect HCV core Ag assay may be an alternative method for hepatitis C diagnosis, performed on the same analytical platform and sample as the anti-HCV assay, shortening the diagnostic window period, demonstrating good correlation with HCV RNA assay with high specificity and positive predictive value.

miR-370 suppresses HBV gene expression and replication by targeting nuclear factor IA

Hepatitis B virus (HBV) infection is a major health problem worldwide. The roles of microRNAs in the regulation of HBV expression are being increasingly recognized. In this study, we found that overexpression of miR-370 suppressed HBV gene expression and replication in Huh7 cells, whereas antisense knockdown of endogenous miR-370 enhanced HBV gene expression and replication in Huh7 cells and HepG2.2.15 cells. Further, we identified the transcription factor nuclear factor IA (NFIA) as a new host target of miR-370. Overexpression and knockdown studies showed that NFIA stimulated HBV gene expression and replication. Importantly, overexpression of NFIA counteracted the effect of miR-370 on HBV gene expression and replication. Further mechanistic studies showed that miR-370 suppressed HBV replication and gene expression by repressing HBV Enhancer I activity, and one of the NFIA binding site in the Enhancer I element was responsible for the repressive effect of miR-370 on HBV Enhancer I activity. Altogether, our results demonstrated that miR-370 suppressed HBV gene expression and replication through repressing NFIA expression, which stimulates HBV replication via direct regulation on HBV Enhancer I activities. Our findings may provide a new antiviral strategy for HBV infection. J. Med. Virol. 89:834-844, 2017. © 2016 Wiley Periodicals, Inc.

Systematic review of the accuracy of antibody tests used to screen asymptomatic adults for hepatitis C infection

BACKGROUND

Several expert groups, including the United States Preventive Services Task Force and the Canadian Task Force on Preventive Health Care, have recently examined or are currently examining whether primary care physicians should screen asymptomatic adults for hepatitis C virus (HCV) infection. To inform decision-making on HCV screening, we performed a systematic review of the accuracy of antibody tests compared with other immunoassays and RNA detection for screening asymptomatic adults for HCV infection in Canada.

METHODS

MEDLINE and Embase databases were searched from 1990 to 2016; resulting citations were uploaded into DistillerSR and independently screened by 2 reviewers. Original research studies, systematic reviews and meta-analyses were eligible for inclusion. At least 80% of the study population had to be asymptomatic, nonpregnant, treatment-naïve adults with unknown liver enzyme values and unknown HCV status. Risk of bias was assessed with the use of the Quality Assessment of Diagnostic Accuracy Studies version 2 (QUADAS-2) tool; the quality of the body of evidence was assessed by means of GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology.

RESULTS

Of 1537 articles identified, 81 underwent full-text review, and 9 studies met the inclusion criteria. Compared with RNA detection, the sensitivity of the third-generation enzyme-linked immunosorbent assay was variable (61.0%-81.8%), and its specificity was high (97.5%-99.7%). As expected, there were more false-positive results when comparing antibody tests to RNA detection than to other immunoassays. Our GRADE assessment suggested that there was a high concern for risk of bias, particularly verification bias, and substantial inconsistency between studies in terms of their design.

INTERPRETATION

More research is needed to better characterize the accuracy of antibody tests used to screen for HCV infection in the general population. Jurisdictions that recently adopted birth cohort screening for HCV infection are encouraged to evaluate and report on the accuracy of HCV screening tests and screening benefits and harms. PROSPERO registration: no. CRD42016039710.

Review of Laboratory Tests used in Monitoring Hepatitis B Response to Pegylated Interferon and Nucleos(t)ide Analog Therapy

There are only two currently approved classes of hepatitis B virus (HBV) antiviral agents, pegylated interferon (Peg-IFN), and nucleos(t)ide analogs (NAs) for chronic HBV infection. Although Peg-IFN is used for a finite 48-week duration and offers a greater chance of sustained off-treatment virological response, it is poorly tolerated and can only be offered to selected patients. The NAs are well tolerated but require prolonged therapy due to risk of relapse with treatment cessation. There is evolving data that novel virological assays (e.g., quantitative hepatitis B surface antigen, quantitative hepatitis B core antigen, quantitative antibody to core protein) in combination with hepatitis B genotype and more sensitive HBV DNA polymerase chain reaction (PCR) assays may be useful to predict response to IFN as well as off-treatment NA durability. Utilization of these clinical laboratory tests may be important given the development of novel anti-HBV therapies, hoping to achieve a cure for chronic hepatitis B infection.

Hepatitis C Viral Infection in Children: Updated Review

Hepatitis C virus (HCV) infection is a major medical challenge affecting around 200 million people worldwide. The main site of HCV replication is the hepatocytes of the liver. HCV is a positive enveloped RNA virus from the flaviviridae family. Six major HCV genotypes are implicated in the human infection. In developed countries the children are infected mainly through vertical transmission during deliveries, while in developing countries it is still due to horizontal transmission from adults. Minimal nonspecific and brief symptoms are initially found in approximately 15% of children. Acute and chronic HCV infection is diagnosed through the recognition of HCV RNA. The main objective for treatment of chronic HCV is to convert detected HCV viremia to below the detection limit. Children with chronic HCV infection are usually asymptomatic and rarely develop severe liver damage. Therefore, the benefits from current therapies, pegylated-Interferon plus ribavirin, must be weighed against their adverse effects. This combined treatment offers a 50-90% chance of clearing HCV infection according to several studies and on different HCV genotype. Recent direct acting antiviral (DAA) drugs which are well established for adults have not yet been approved for children and young adults below 18 years. The most important field for the prevention of HCV infection in children would be the prevention of perinatal and parenteral transmission. There are areas of focus for new lines of research in pediatric HCV-related disease that can be addressed in the near future.