Autoantibodies to asialoglycoprotein receptor (ASGPR) measured by a novel ELISA—Revival of a disease-activity marker in autoimmune hepatitis

BackgroundThe liver-specific ASGPR is an autoantigen in autoimmune hepatitis (AIH) patients. Anti-ASGPR antibody correlates with disease activity, however, only in-house assays have been reported so far.MethodsRabbit ASGPR was purified by affinity chromatography on galactose-Sepharose and used for standardised detection of anti-ASGPR by ELISA. Anti-ASGPR IgG was measured in sera from 45 patients with AIH, PBC (n = 43), alcoholic liver disease (n = 13), HBV infection (n = 35), HCV infection (n = 53), and 118 blood donors. Anti-ASGPR was correlated with biochemical parameters of disease activity in 22 AIH patients with consecutive samples.ResultsTwenty-one of 30 untreated (70%) and five of 15 treated AIH patients (30%) showed elevated anti-ASGPR at first presentation. Only one blood donor demonstrated anti-ASGPR. ALD and PBC patients were all negative. ROC curve analysis of AIH and disease-control patients revealed a sensitivity of 77.8% and a specificity of 99.4%. Three (8.6%) of 35 HBV and 7 (13.2%) of 53 HCV patients demonstrated elevated anti-ASGPR. In AIH patients, anti-ASPGR correlated with liver-transaminases levels. In 22 follow-up patients, elevation of anti-ASPGR preceded liver-transaminases increase.ConclusionsThe novel anti-ASGPR ELISA is a readily available and specific diagnostic tool for anti-ASGPR detection in AIH. Quantification of anti-ASGPR is helpful in monitoring disease activity.