Background/aims: The asialoglycoprotein receptor (ASGPR) is an established, liver-specific autoantigen. This multicenter study investigated the specificity of anti-ASGPR autoantibodies for autoimmune hepatitis (AIH) in different ethnic groups.
Methods: Nine hundred fourteen sera from European, Japanese, and North American (U.S.) patients with chronic inflammatory liver disorders were tested. An enzyme-immunoassay using human ASGPR and a radioimmunoassay against rabbit ASGPR, performed independently on coded sera, were compared.
Results: The highest frequency (76%) of anti-human ASGPR was found in AIH patients (11/24 U.S.; 21/25 European; 28/30 Japanese), particularly in those with active disease before treatment (53/62, 85%), and decreased in titer with response to immunosuppressive therapy. These antibodies were found at low titers in 43 (11%) of 385 patients with viral hepatitis and in 25 (7.6%) of 328 patients with other chronic inflammatory liver disorders (P < 0.0005 compared with all AIH patients). Twenty of 37 sera tested by enzyme-immunoassay and radioimmunoassay were positive, and nine were negative for anti-ASGPR by both assays (78% concordance); six sera were exclusively positive on human substrate.
Conclusions: Circulating anti-ASGPR autoantibodies are closely associated with autoimmune hepatitis independent of geographic or ethnic criteria. Two anti-ASGPR assays currently in use show high reliability.