[Sensitivity and specificity of 2 methods of determining surface antigen (HBsAg) in various forms of hepatitis B...

A passive haemoagglutination method (rHA) was compared to a solid-phase radioimmunoassay (RIA) in detecting hepatitis B surface antigen (HBsAg) in order to evaluate their sensitivity and specificity. The test was performed on sera from 297 subjects with acute and chronic hepatitis, 23 asymptomatic HBsAg-RIA positive carriers, 20 patients with infectious mononucleosis, 110 HBsAg RIA negative healthy persons; 30 sera positive for rheumatoid factor and/or autoantibody were also tested. Our data confirm that RIA is highly specific and rarely shows false negative results, depending on antibody excess, rHA shows less sensitivity than RIA in detecting HBsAg especially in sera of patients with acute hepatitis.