Detection and clinical significance of acetone-insoluble liver cell membrane antigen in sera of patients with chronic active liver diseases.

An enzyme-linked immunosorbent assay was developed to detect insoluble liver cell membrane antigen (LMAg) which gives rise to serum LMA (anti-LM) in HBsAg-negative patients. The optical density (OD) ratio of the average LMAg level of normal subjects was less than 1.2. In HBsAg-positive cases, high LMAg levels (OD ratio greater than 2.4) were noted in 8 of 8 patients with acute hepatitis (AH), 3 of 8 with chronic persistent hepatitis (CPH), 5 of 10 with moderate chronic aggressive hepatitis (CAH), 7 of 10 severe CAH and 4 of 8 with liver cirrhosis (LC). In HBsAg-negative cases, however, high LMAg levels were noted in only 6 of 8 patients with AH, 1 of 10 with CPH, 1 of 10 with moderate CAH, 1 of of 10 with severe CAH, 0 of 8 with LC, 0 of 8 with fatty liver and 5 of 10 with alcoholic hepatitis. In micro-immunodiffusion experiments, intensively absorbed rabbit anti-rat LM precipitated two organ-specific components of rat liver homogenate, one of which was identical to liver specific protein (LSP). In immunohistochemical demonstrations of LMAg and LSP, anti-LM, prepared from the serum of a HBsAg-negative CAH patient, bound to both human and rat acetone-fixed liver cell membranes, but not to those of human or rat kidneys. Absorbed rabbit anti-rat LM also bound to liver cell membranes, but absorbed anti-rat LSP lacked organ-specificity when assayed with the immunofluorescence technique using acetone-fixed liver sections. In conclusion, the appearance of serum LMAg was associated with high-SGPT patients and HBsAg-positive CAH patients.