ELISA in serodiagnosis of HCV infection

A high level of anti-HCV is generally associated with viral replication and the number of recognized epitopes appears to be correlated with the viral charge. Nevertheless, the absence of detectable antibodies in about 60% of patients during the acute phase of the disease and in 10% of chronically infected (generally immunocompromised subjects) are heavy handicaps for HCV serology. Moreover, low levels of anti-HCV antibodies can persist after complete recovery, and HCV viremia does not appear to be associated with the presence of a special antibody specificity. The immunoblots presented as 'confirmatory test' always appear to be less sensitive than the screening tests and therefore are unable to discriminate between post-infection antibodies and false-positive reactions, as rare as they can be. In these cases, as in non-responder patients, PCR appears essential. The possible reasons of immune response limitations and the possible improvements of HCV serology are discussed.