Differentiation between autoimmune hepatitis and hepatitis C virus related liver disease

In some patients differentiation between autoimmune hepatitis and chronic viral disease may be difficult. In patients with chronic active hepatitis the coincidence of various types of autoantibodies and antibodies to hepatitis C virus (HCV-Ab) has been reported. It is important to diagnose the true etiology of the underlying liver disease because treatment for viral disease and autoimmune hepatitis is different. This paper reports about five patients who were referred to the liver outpatient clinic with the diagnosis of chronic active hepatitis. All of them had antibodies to liver-pancreas-antigen (LP-Ab) and HCV-Ab. Some authors believe that LP-Ab and anti-soluble-liver-antigen antibodies (SLA-Ab) are found with the same entity of autoimmune hepatitis. Nevertheless none of our patients had detectable antibodies against Cytokeratin 8/18, the major target antigen of SLA-Ab positive autoimmune hepatitis. Serum transaminases were elevated for more than 6 months and all patients were positive for HCV-RNA by PCR. Three patients had a history of exposure to blood products. In all five patients liver biopsy showed chronic active hepatitis compatible with chronic hepatitis C. All patients were treated with alfa-interferon. In four of five patients interferon led to improvement or normalization of serum transaminases. Thus we conclude that in a considerable number of patients with chronic active hepatitis associated with both LP-Ab and HCV-Ab, hepatitis C virus is the true etiology. Such patients with both LP-Ab and HCV-Ab may successfully be treated with alfa-interferon.(ABSTRACT TRUNCATED AT 250 WORDS)