Liver Membrane Antibodies Detected by Immunoradiometric Assay in Acute and Chronic Virus‐Induced and Autoimmune Liver Disease

In this study, we describe a radioimmunoassay to detect liver membrane binding antibodies. The assay was designed to exclude binding of aggregated IgG or immune complexes to Fc 7 receptors of hepatocytes. When this assay was applied to sera from 142 patients, antibodies were found in highest titer in patients with autoimmune chronic active hepatitis, rarely in patients with hepatitis B virus‐induced chronic active liver disease, and in 32% of patients with primary biliary cirrhosis. IgM antibodies were found in 100% of patients with acute Type A but not B or non‐A, non‐B hepatitis. IgA class antibodies were found in the sera of 57% of patients with alcohol‐induced hepatitis. All patient groups showing significant titers of liver membrane antibodies display the lesion of piecemeal necrosis except those with alcohol‐induced hepatitis. Further studies are needed to determine whether this antibody is the cause of the lesion.