Immunoglobulin M antibodies against hepatitis C virus antigens: significance and applications.

The immunoglobulin M antibody against hepatitis C viral capsid (core) antigen has been found to be a possible marker for acute infection in post-transfusion hepatitis C. We extended this observation to a sporadic hepatitis C. In addition, a modified recombinant immunoblot assay (RIBA) that contained three HCV antigens (capsid, NS3 and NS5) in one strip was developed and used to study the antibody response among patients. This allowed a simultaneous comparison of either immunoglobulin M or G specific to individual HCV antigen and yielded more information. The assay was found useful in the diagnosis of acute hepatitis C in clinically uncertain cases.