Autoantibodies against the human asialoglycoprotein receptor: Effects of therapy in autoimmune and virus-induced chronic active hepatitis

Abstract

The hepatic asialoglycoprotein receptor (ASGPR) was recently identified as a target antigen for both humoral and cellular immune response in inflammatory liver diseases. Thereby anti-ASGPR autoantibodies directed against human substrate were closely associated with autoimmune chronic active hepatitis. The present study compares the occurrence, titer and immunoglobulin classification of anti-human(h-)-ASGPR antibodies in 23 patients with newly diagnosed autoimmune chronic hepatitis before and after initiation of immunosuppressive therapy to 22 patients with autoimmune hepatitis in remission. Additionally, 1-year follow-up examinations of 42 patients with HBsAg-positive chronic hepatitis and of 32 patients with chronic hepatitis C receiving recombinant interferon-alpha were included. Nineteen of 23 patients with newly diagnosed and 9/22 with autoimmune hepatitis in remission, 5/42 with untreated chronic hepatitis B and 5/32 patients with chronic hepatitis C exhibited anti-h-ASGPR at the beginning of the study. In autoimmune hepatitis anti-h-ASGPR were found in higher titers (median > 1:1000) than in viral hepatitis (maximum 1:400). After initiation of immunosuppressive therapy in autoimmune hepatitis anti-h-ASGPR decreased sharply. Eight of 19 patients eliminated anti-h-ASGPR within 18 months in contrast to 11 patients with persistent anti-h-ASGPR titer over 18 months and longer. Anti-h-ASGPR with maximum titer of 1:600 were detected in 5 patients with chronic hepatitis B (transiently in 4/5 patients) and in 2 patients with chronic hepatitis C during interferon-alpha. Anti-h-ASGPR were from immunoglobulin classes IgG and IgM in cases with untreated autoimmune hepatitis and chronic hepatitis B and C exhibiting mainly IgG2-subclass in autoimmune and IgG4 in viral hepatitis.(ABSTRACT TRUNCATED AT 250 WORDS)