title: Serodiagnosis of viral hepatitis A by a solid-phase radioimmunoassay specific for IgM antibodies.
abstract: A solid-phase radioimmunoassay for detecting specific IgM antibodies to hepatitis A virus (HAV) was developed and characterized. The test utilized microtiter plates coated with anti-IgM to specifically absorb the IgM antibodies from the test serum. The anti-hepatitis A IgM antibodies are measured by the specific consecutive binding of hepatitis A antigen and radiolabelled anti-hepatitis A antibodies (anti-HA). In 6 chimpanzees infected with HAV, IgM anti-HA was detected from about the first date of elevated transaminases and was positive for about 3 months. The usefulness of the test was confirmed by testing acute phase sera of 30 patients from a common source outbreak of epidemic hepatitis, and negative sera from 2 control groups. A collection of serum specimens from 190 patients with sporadic HBsAg-negative hepatitis in Brazil was also tested and an etiologic association with HAV was confirmed in the majority of these cases.
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis*; D006506:Hepatitis A / Q000175:diagnosis*; D006507:Hepatovirus / Q000276:immunology; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D002679:Pan troglodytes; D011863:Radioimmunoassay / Q000379:methods; D012217:Rheumatoid Factor / Q000032:analysis
chemical_list: D000914:Antibodies, Viral; D007075:Immunoglobulin M; D012217:Rheumatoid Factor; D000410:Alanine Transaminase