title: LM-Ag and LSP--two different target antigens involved in the immunopathogenesis of chronic active hepatitis?
abstract: Two different types of immune reactions against liver membrane antigens have been described: firstly, cell-mediated immunity and autoantibodies against the liver-specific protein (LSP) in HBsAg-negative and HBsAg-positive chronic active hepatitis (CAH), and secondly, a liver membrane autoantibody (LMA) in HBsAg-negative CAH. Using 100,000 g supernatants of human and rabbit liver homogenates, the corresponding antigen of LMA could be separated by affinity chromatography on insolubilized LMA-positive sera from patients with HBsAg-negative CAH. A further characterization by crossed immunoelectrophoresis showed that LMA is directed against a soluble liver membrane antigen (LM-Ag) that is not a constituent of the purified LSP. LM-Ag seems to be species-unspecific and moves faster than LSP and serum albumin in crossed immunoelectrophoresis. While LSP is believed to be involved in the pathogenesis of HBsAg-negative and HBsAg-positive chronic active hepatitis, LM-Ag may be a target antigen only in cases of HBsAg-negative autoimmune CAH.
mesh_terms: D000941:Antigens / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology; D002462:Cell Membrane / Q000276:immunology; D002846:Chromatography, Affinity; D002908:Chronic Disease; D006505:Hepatitis / Q000276:immunology*; D006514:Hepatitis B Surface Antigens; D006801:Humans; D007123:Immunoelectrophoresis, Two-Dimensional; D008099:Liver / Q000276:immunology*; D008565:Membrane Proteins / Q000276:immunology
chemical_list: D000941:Antigens; D001323:Autoantibodies; D006514:Hepatitis B Surface Antigens; D008565:Membrane Proteins