title: Acute type B hepatitis among HBsAg negative patients detected by anti-HBc IgM.
abstract: A consecutive group of 169 patients with acute hepatitis found negative for hepatitis B surface antigen (HBsAg) and negative for IgM antibody against hepatitis A (anti-HAV IgM) was studied for presence of IgM antibody against hepatitis B core antigen (anti-HBc IgM) by ELISA. Anti-HBc IgM was found in a total of 34 of 60 patients with detectable total anti-HBc. One hundred and nine patients had no detectable anti-HBc IgM and no total anti-HBc and were thus considered as having acute non-A, non-B hepatitis. Among the 34 patients with anti-HBc IgM in their first serum sample, 23 were anti-HBs negative and all had high and steadily decreasing ratio unit (RU) values for anti-HBc IgM (mean RU value 17.1). Twelve of the 23 patients showed seroconversion to anti-HBs during the follow-up, indicating an actual hepatitis B virus infection. Eleven of the 34 anti-HBc IgM positive patients had anti-HBs in their first serum sample. In this group, the RU values for anti-HBc IgM were high and steadily declining and the initial values were significantly lower (mean RU value 9.9) (p less than 0.05) than in the anti-HBs negative group. Evidence is provided that anti-HBc IgM in serum from patients with HBsAg negative hepatitis with or without anti-HBs indicates an actual hepatitis B virus infection. According to generally accepted criteria, the demonstration of anti-HBc IgM identified 20% of the 169 patients with acute non-A, non-B hepatitis as having an actual hepatitis B infection.
mesh_terms: D000208:Acute Disease; D000888:Antibodies, Anti-Idiotypic / Q000032:analysis*; D005189:False Positive Reactions; D006509:Hepatitis B / Q000175:diagnosis*; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D007075:Immunoglobulin M