title: Serodiagnosis of viral hepatitis A by a modified competitive binding radioimmunoassay for immunoglobulin M anti-hepatitis A virus.
abstract: A competitive binding radioimmunoassay (CBA) for antibody to hepatitis A virus (HAV) was evaluated and compared with a standard solid-phase radioimmunoassay for anti-HAV, CBA was found to be sensitive and specific for the detection of anti-HAV, as demonstrated by the 98% concordance of CBA and solid-phase radioimmunoassay test results. The standard CBA test was modified for the differential detection of acute (immunoglobulin M) and convalescent (immunoglobulin G) anti-HAV by incorporation of a step in which immunoglobulin G anti-HAV was preferentially absorbed with S. aureus cells (protein A). The modified CBA test was shown to be capable of differentiating between acute- and convalescent-phase sera. The modified CBAM test was able to detect immunoglobulin M anti-HAV up to approximately 4 weeks after the onset of illness.
mesh_terms: D000208:Acute Disease; D000818:Animals; D000914:Antibodies, Viral / Q000032:analysis*; D000918:Antibody Specificity; D003289:Convalescence; D006506:Hepatitis A / Q000175:diagnosis*; D006507:Hepatovirus / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis*; D011863:Radioimmunoassay / Q000379:methods*
chemical_list: D000914:Antibodies, Viral; D007074:Immunoglobulin G; D007075:Immunoglobulin M