title: Immunoglobulin M antibodies to hepatitis B core antigen: evaluation of enzyme immunoassay for diagnosis of hepatitis B virus infection.
abstract: In acute and chronic hepatitis B, antibodies of the immunoglobulin M (IgM) class against the hepatitis B core antigen (anti-HBc IgM) have been demonstrated. For the determination of anti-HBc IgM, a sensitive enzyme immunoassay with anti-mu-coated flat-bottomed microtiter plates is described and evaluated. The specificity of the anti-HBc IgM test system was proven by pretreatment of presumed anti-HBc IgM-positive samples with anti-mu to block anti-HBc IgM. The test system was highly sensitive. In the acute stage of hepatitis B, anti-HBc IgM could be demonstrated in serum dilutions up to 10(-7) (mean titer, 10(-5)), and in sera from patients with chronic hepatitis B, the mean titer was 10(-3). In a study of unselected patients whose sera were sent at irregular intervals for testing, anti-HBc IgM persisted in a high percentage (52%) for at least 13 to 18 months after onset of illness despite the fact that these patients eliminated hepatitis B surface antigen (HBsAg) and produced antibodies to HBsAg (anti-HBs). By using the anti-HBc IgM test as an additional aid in the diagnosis of acute HBsAg-negative hepatitis, the hepatitis B etiology could be established in 13 of 42 patients (31.4%). Investigations of the prevalence of anti-HBc IgM in different groups of patients with chronic hepatitis B infection showed 89.4% anti-HBc IgM-positive results in patients with chronic active hepatitis B, 60% in patients with HBsAg-negative chronic active hepatitis, 58.2% in patients with primary liver carcinoma and markers of hepatitis B infections, and 34.9% in healthy carriers of HBsAg.
mesh_terms: D000914:Antibodies, Viral / Q000032:analysis*; D006528:Carcinoma, Hepatocellular / Q000276:immunology; D002353:Carrier State / Q000276:immunology; D000939:Epitopes; D006509:Hepatitis B / Q000175:diagnosis* / Q000276:immunology; D006510:Hepatitis B Antibodies / Q000032:analysis*; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006801:Humans; D007124:Immunoenzyme Techniques; D007075:Immunoglobulin M / Q000032:analysis*; D008113:Liver Neoplasms / Q000276:immunology
chemical_list: D000914:Antibodies, Viral; D000939:Epitopes; D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D007075:Immunoglobulin M