ABSTRACT
Hepatitis C virus [HCV] is an important etiologic agent for chronic liver diseases in Egypt. Positivity of anti-HCV antibodies indicates past or current infection and in contrast to molecular detection of HCV-RNA does not give any indication about viral replication. Several problems still persist when RT-PCR is used for screening of patients. Recently, the availability of an anti-core antigen monoclonal antibody allowed development of an enzyme-linked immunosorbent assay [ELISA] detecting and quantifying total HCV core Ag [C-Ag] in peripheral blood of HCV-infected patients. The aim of this study is to evaluate the usefulness of the total HCV C-Ag in determining viremia compared to HCV-RNA detected by RT-PCR among anti-HCV positive Egyptian patients. In this study, 143 anti-HCV antibody positive patients were tested for HCV-RNA by PCR and HCV-Core antigen to evaluate the sensitivity and specificity of the latter. Among those 116 cases [81.11%] were HCV-RNA+ve and 111 [77.68] cases were HCV-Core Ag +ve, while 27 cases [18.84%] were HCV- RNA negative and 32[22.32%] were HCV-Core Ag -ve. Out of 116 patients who were HCV- RNA +ve, 111 [95.65%] were HCV-Core Ag +ve also, while 5 [4.35%] cases all with low viral load were negative. The sensitivity, specificity, PPV and NPV of HCV-Core Ag when referred to HCV-RNA were 95.7%, 100%, 100% and 84.4% respectively. Thus positive total HCV Core Ag could be a useful test in clinical practice to determine HCV viremia with a sensitivity and specificity close to that of PCR assays. However, a negative test is not reliable to exclude low viral load