SERUM BINDING ACYIVITY FOR PHSA DUE TO ANTIBODIES DETECTED BY ENZYME IMMUNOSORBENT ASSAY IN ACUTE AND CHRONIC TYPE B,A AND NANB VIRAL HEPATITIS

Polymerized human serum albumin (pHSA) binding activity due to antibodies was evaluated by a sensitive and specific enzyme-linked immunosorbent assay (ELISA) in well characterized cases of acute (AVH) and chronic active (CAH) viral hepatitis. Moreover, hepatitis B virus (HBV) infection serum samples were tested for the presence of HBsAg-associated pHSA receptors detected by radioimmunoassay. Specificity of ELISA in detecting pHSA binding activity due to antibodies was assayed by testing IgG fractions from positive serum samples and purified HBsAg particles. A very high prevalence (mean = 87%) of antibody response to pHSA was detected in serum samples of patients with type B, A and post-transfusion non-A, non-B (NANB) AVH and CAH. IgM antibodies were found in 75% of type B AVH, in 77% of type A AVH and in none of the NANB cases at the onset of illness. In CAH, IgM antibodies were found in 37.5% of HBsAg-positive cases and in 44% of NANB cases. In HBV-related AVH and CAH no correlation was found between anti-pHSA antibodies and HBsAg-associated pHSA receptors or the HBeAg/anti-HBe status. The antibody response detected by ELISA showed a cross-reactivity with monomeric human albumin and heterologous polymeric and monomeric albumins. However, in HBV infection the antibody binding was significantly higher for pHSA than for monomeric human albumin or albumins from other species, thus suggesting that the antigenic sites of pHSA evoking the antibody response may differ in relation to the etiology of viral hepatitis.