Clinical and serological differentiation of autoimmune and hepatitis C virus-related chronic hepatitis

Abstract
Recent reports have focused on the difficulty in differentiating autoimmune hepatitis from chronic hepatitic C due to the high prevalenc of anti-HCV in autoimmune hepatitis. The aim of this study was to identify clinical, biochemical, and serological variables that would help distinguish these two diseases. Pretreatment clinical and biochemical variables were compared from 17 patients with steroid-responsive autoimmune chronic active hepatitis and 62 patients with chronic hepatitis C. Serum samples from these patients were tested for autoantibodies and for anti-HCV by first- and second-generation ELISA, recombinant immunoblot assay, and HCV RNA by polymerase chain reaction. Patients with autoimmune hepatitis were more likely to be symptomatic (94% vs 47%,PPP<0.003). Patients with chronic hepatitis C who were ANA positive were older than those who were ANA negative, although there were no other differences in clinical or biochemical features between these groups. In particular, there was no difference in response rate to antiviral therapy. Thus, autoantibodies are frequently found in chronic hepatitis C, especially in older subjects, but appear to be clinically insignificant. Anti-HCV is frequently present in autoimmune hepatitis but is rarely confirmed by tests of higher specificity. These findings have important implications in selecting patients for antiviral or immunosuppressive therapy.