Virus-induced autoimmunity in hepatitis C virus infections: a rare event.
Serial serum samples from 16 Italian patients presenting with acute hepatitis C virus (HCV) infections (which progressed to chronic hepatitis in six) were screened for the non-organ-specific autoantibodies most frequently associated with autoimmune hepatitis (AIH), as well as for antibodies against the hepatic asialoglycoprotein receptor (ASGP-R) and against the GOR peptide. One patient had low titres (1:10-1:80) of liver-kidney microsomal (LKM-1) antibodies during the recovery phase and three others had transient low titres of anti-smooth muscle (IgM class, 1:10) or anti-ASGP-R (1:150-1:300). Anti-GOR was detected in 43 (65%) of 66 sera from 13 of these patients. There was no correlation between any of these findings and progression to chronicity. By comparison, 18 patients with AIH studied concurrently before institution of immunosuppressive therapy all had antinuclear and/or smooth muscle antibodies, or LKM-1, at 1:40-1:640 and anti-ASGP-R at 1:300-1:2,100. None of these 18 had evidence of HCV infection and all were seronegative for anti-GOR. The findings indicate that the autoantibodies usually associated with AIH are rare in HCV infections but the virus can very occasionally induce a transient autoimmune response. Anti-GOR appears to be an antibody specifically related to HCV infection and is probably not a marker of induced autoimmunity, and it does not predict progression to chronic hepatitis.