Hepatitis-Associated Antigen: Improved Sensitivity in Detection

Abstract

A simple method for improving the detection of the hepatitis-associated antigen (HAA) by concentrating the test serum is described. Sensitivity is improved approximately tenfold for the double diffusion technic, without incurring the difficulties associated with performing a complement-fixation test or requiring the equipment needed for electrodiffusion. The routine and concentrated technics were compared using serum specimens from patients with serum hepatitis, infectious hepatitis, and unresolved hepatitis, as well as sera from “normal” blood donors. Of the HAA positive patients with serum transaminase activity in excess of 1,000 units, 20% were positive by concentration only. In convalescence, when the SGPT activity had dropped below 100, it was unusual to identify HAA except by concentration.