[The hepatitis C virus--principal causative agent in non-A, non-B hepatitis].

The diagnosis of non-A, non-B (NANB) hepatitis was based on the exclusion of hepatitis A and B infection and other known causes of hepatitis, such as other viruses, alcohol and toxic effects. More recently, an RNA has been isolated from a NANB-infected chimpanzee serum and with its aid a polypeptide antigen was produced by molecular biological methods. Antibodies to this antigen--as part of the infectious agent, called hepatitis C virus (HCV)--were detected in the sera of infected patients. Studies with this antigen/antibody system proved, the HCV is responsible for the majority of posttransfusion and sporadic NANB hepatitis cases worldwide. The antibody appears late, in the serum up to 6 months after the infection. The occurrence of the infection is high among hemophiliacs and drug abusers. Anti-HCV antibody was detected also in certain liver disease with "unknown etiology" (chronic active hepatitis, primary biliary cirrhosis). This newly developed test provides the possibility to prove HCV infection in different groups of patients by detecting an antibody to a component of HCV.