Chronic hepatitis. Aetiology and current management.

The entity of chronic hepatitis has long been an enigma, and its treatment confusing. Recent studies have indicated the importance of excluding causes such as drugs, Wilson's disease and alpha 1-antitrypsin deficiency. After excluding such causes, there are 3 major groups--'autoimmune', hepatitis B, and non-A, non-B (NANB) in all of which an immunological basis for pathogenesis exists. The autoimmune group has been subdivided into a milder type (chronic persistent hepatitis) and a more severe type (chronic active hepatitis) on histological grounds. Corticosteroids are indicated in chronic active hepatitis if cirrhosis or bridging necrosis is present. However, corticosteroids are contraindicated in disease due to the hepatitis B virus where chronic active hepatitis correlates with the presence of replicating virus (serum positive for e antigen, DNA polymerase and HBV-DNA), and in such cases antiviral agents and immunomodulation are being studied. Very little is known about NANB hepatitis in the absence of an assay and there may be more than a single agent. In hepatitis B, the development of serological markers, molecular probes (HBV-DNA), natural animal hepatitis with near-identical viruses, and delta antigen (a virus requiring co-infection with hepatitis B) have all extended our knowledge so dramatically that it is hoped that the enigma of chronic hepatitis will be solved when an assay for NANB hepatitis becomes available.