Hepatic membrane antibodies: studies of prevalence and specificity

Using a newly developed assay for hepatic membrane-associated antibodies (HMA), we studied the prevalence and specificity of HMA in a variety of acute and chronic liver diseases to evaluate the usefulness of such an assay system. Sera were examined by indirect immunofluorescence on rat liver sections previously fixed in Bouin's fluid. As compared with a prevalence of 4% in 45 healthy controls, HMA were detected in 73% of 45 patients with chronic active hepatitis (CAH) (P less than 0.001) and in all 11 patients with primary biliary cirrhosis (PBC) (P less than 0.001). HMA were also present in 38% of 40 patients with acute viral hepatitis, 47% of 27 with alcoholic liver disease and 33% of 24 with other liver diseases not thought to be immunologically mediated. In 53 patients studied with other liver, gastrointestinal or autoimmune diseases, the prevalence of HMA was not increased over controls. Absorption studies showed that seven of 14 HMA positive sera contained specificities for polymerized human serum albumin (pHSA) or liver-specific protein (LSP) or both antigens. HMA positive samples reacted occasionally with rat kidney tubular epithelial membranes but did not appear to react with other tissues. These results demonstrate that HMA are present at higher prevalence in the autoimmune liver diseases than many previously described autoantibodies and are reactive in part to specificities on pHSA and LSP.