Evaluation of five screening tests licensed in Argentina for detection of hepatitis C virus antibodies

The serological markers of acute infection with hepatitis A, B, C, D, E and G viruses revisited

Viral hepatitis is a liver infection caused by one of the six hepatitis viruses: hepatitis A, B, C, D, E, and G virus (HAV to HEV and HGV). These agents differ in their biological, immunological, pathological and epidemiological characteristics. They cause infections that, when symptomatic, lead to clinical manifestations and laboratory findings that are not specific to a particular virus, often making differential diagnosis difficult, especially when no knowledge is available regarding the patient's medical history or the epidemiological background. A number of acute-phase serological markers, such as anti-HAV, anti-HBc, anti-HDV and anti-HEV IgM antibodies, are able to provide a clear indication of an infection caused by HAV, HBV, HDV or HEV. Anti-HCV antibodies and HGV/RNA are used for the diagnosis of HCV and HGV infections. The importance of each of these markers will be reviewed, and different factors that can interfere with the diagnosis of acute infections caused by these viruses will be described.

Diagnostic Performance of an Immunoassay for Simultaneous Detection of Hcv Core Antigen and Antibodies among Haemodialysis Patients

Nosocomial transmission of HCV is a concern in haemodialysis (HD) units worldwide. Diagnosis of HCV infection among dialysis patients is currently based on the detection of anti HCV antibodies by ELISA, and is confirmed by HCV RNA. The average window period between HCV infection and seroconversion with new generations of HCV antibody tests remains approximately 70 days with more prolonged period among dialysis patients. In this study we assessed the diagnostic performance of an immunoassay designed for simultaneous detection of anti HCV antibodies and core antigen in one step in comparison to qualitative RT-PCR and anti HCV antibodies detection test among Egyptian haemodialysis patients. The studied patients were 39 chronic renal failure patients on maintenance haemodialysis. The results obtained in the present study revealed HCV infection of 56.4%. Combined Ag/Ab test detected 3 out of the 4 anti-HCV negative viraemic patients who were in the window period. The sensitivity, specificity and accuracy of the test were higher than that of anti HCV antibodies detection test (95.45%, 94.1% and 94.87% versus 81.8%, 88.23% and 84.6%) and they were raised to 100% on combining its positivity with liver enzymes elevation results. Therefore, this simple combined Ag/Ab test can be applied for early detection of HCV infection during window period among HD patients as an alternative to HCV RNA detection.

Characterization and application of monoclonal antibody against hepatitis C virus nonstructual protein three

Developing assays for detecting HCV antigens could be beneficial because viral proteins appear earlier than antibodies and are more stable than RNA in the serum. Monoclonal antibody was prepared by immunization and cell fusion. Subclass, specificity, and efficiency of monoclonal antibodies were determined by ELISA. Epitope specificity of monoclonal antibodies was analyzed by ELISA additivity test. HCV antigen in serum of hepatitis patients was examined by double monoclonal antibody sandwich ELISA. Five hybridoma cell lines were screened and named HCV(1), HCV(2), HCV(3), HCV(4), and HCV(5). These five monoclonal antibodies had high specificity and efficiency. The additivity test showed that HCV(2), HCV(4), and HCV(5) recognized different epitopes, which can be matched in ELISA. Of 173 anti-HCV positive patients, 37 (21.4%) were positive for HCV antigen. Of 1498 anti-HCV negative patients, 10 (0.67%) were positive for HCV antigen. Fifty normal controls were negative for HCV antigen. HCV antigen detection had moderate agreement and correlation with HCV RNA detection (kappa=0.577, p<0.01; r=0.59, p<0.01). This result indicates that the monoclonal antibody against HCV NS(3) may be a potential diagnostic reagent, which would provide a foundation for developing a sandwich ELISA of HCV antigen detection.