Detection and characterization of antibody to liver cell membrane in sera from patients with chronic active liver diseases.

Sera from 84 patients with chronic liver disease [CLD] (74 chronic active) and from 53 blood donors were tested immunochemically for anti-liver cell membrane antibody (LMAb). LMAb to rat liver tested by an indirect immunofluorescent technique was positive in 53.3% of CLD patients with positive HB surface antibody (HBsAb) and 40.0% of HBsAb positive blood donors. Pepsin digestion of the sera indicated that the binding between liver cell membrane and IgG was at the Fc site on the immunoglobulin. The sera with positive LMAb from HBsAb positive blood donors had elevated Clq-binding activity (Clq-BA). The LMAb to rat liver was a macro-molecular IgG (19-22S IgG) when assayed by Sephadex G-200 column chromatography and 5-40% sucrose density gradient ultracentrifugation. The results suggest that the LMAb in serum from a patient with chronic active liver disease may be an immune complex which consists of various antigens such as HB virus and its antibodies in serum.