Antibody to liver-specific lipoprotein in acute and chronic liver diseases. Its quantitative assay with monoclonal antibody, but without the use of liver-specific lipoprotein.

A double-antibody radioimmunoassay was developed to detect antibody to human liver-specific membrane lipoprotein (anti-LSP antibody) in patients' serum. Anti-human LSP monoclonal antibody was labeled with 125I and anti-anti-LSP antiserum raised in rabbits was used as the first antibody in the assay. Anti-LSP antibody level was quantitatively measured and the assay was shown to be specific. Anti-LSP antibody was found in 5/8 patients with type B acute viral hepatitis (AVH), 3/7 patients with type A AVH, 1/6 patients with non-A, non-B AVH, 10/17 patients with chronic active hepatitis (CAH), 6/16 patients with chronic persistent hepatitis, 13/16 patients with active cirrhosis of the liver and 7/19 patients with primary nonhepatic autoimmune diseases such as glomerulonephritis, systemic lupus erythematosus and rheumatoid arthritis. The mean levels of anti-LSP were increased in patients with cirrhosis of the liver (p less than 0.01), CAH (p less than 0.05) and AVH (p less than 0.05) when compared with that of normal individuals. However, the frequencies of anti-LSP did not depend on HBsAg status. The data showed that anti-LSP antibody can be detected without the use of LSP preparation although it is also found in patients with primary nonhepatic autoimmune diseases.