Antibody to liver membrane antigens in chronic active hepatitis. IV. Exclusion of specific reactivity to polypeptides and glycolipids by immunoblotting.

ABSTRACT

The reactivity of sera was examined in patients with autoimmune chronic active hepatitis and other liver diseases by immunoblotting. Polypeptides and glycolipids of liver plasma membrane, liver-specific lipoprotein and kidney membrane were separated and probed with sera from patients and from a rabbit immunized with mouse liver plasma membrane. Chronic active hepatitis sera reacted with a number of polypeptides in the liver plasma membrane preparations; similar but weaker reactivity was observed with sera from patients with other diseases and in some healthy subjects. Chronic active hepatitis sera did not react with glycolipids from liver plasma membrane. The immune rabbit serum reacted with two polypeptides of 180 kd present in liver plasma membrane but absent from kidney membrane, with two polypeptides of 50 kd which were nonliver-specific but species-specific, and with three major glycolipid components of liver plasma membrane this reactivity thus differed markedly from that of the chronic active hepatitis sera. In studies using dot-blotting, it was found that solubilization of liver plasma membrane in detergents resulted in a marked reduction of the reactivity to liver plasma membrane of chronic active hepatitis sera, but little change in the reactivity of the chronic active hepatitis and other sera with liver-specific lipoprotein by immunoblotting indicated that liver-specific lipoprotein consisted of constituents of liver plasma membrane together with intracellular proteins.(ABSTRACT TRUNCATED AT 250 WORDS)