Methods for detection of anti-albumin autoantibodies in hepatic diseases

Three methods for detection and quantitation of anti-albumin autoantibodies (AAA) in human sera have been developed based on their reaction with a new antigenic site of glutaraldehyde-polymerized human serum albumin (HSA). The first is a double diffusion technique (ID-HSA) were the sera to be tested are reacted with a copolymer of glutaraldehyde activated HSA (copoly-HSA). The reaction is estimated by the lowest copoly HSA concentration giving precipitation with the undiluted sera. The second method is based on agglutination (HA) by AAA positive sera of human red blood cells coated with glutaraldehyde-polymerized HSA (EPA). The reaction is quantified as the highest dilution of sera giving agglutination. The third method uses glutaraldehyde insolubilized HSA as an immunoadorbent able to bind AAA in positive sera. The quantity of protein adsorbed, expessed in microng antibody/ml serum, measures the level of AAA in sera. Significant correlation between the values of AAA as determined by all three methods presented above were recorded.