title: Immunodiagnosis of hepatitis B with high-affinity IgM monoclonal antibodies.
abstract: High-affinity monoclonal IgG and IgM antibodies to hepatitis B surface antigen (HBsAg) have been prepared and their functional capabilities explored by means of solid-phase radioimmunoassays. 125I-labeled HBsAg binding studies indicated that monoclonal IgM antibodies against HBsAg (anti-HBs) coupled to a solid-phase support quantitatively bound more HbsAg at a faster rate than conventionally prepared anti-HBs reagents or other high-affinity IgG monoclonal anti-HBs antibodies. Consequently, IgM anti-HBs was also radiolabeled, and an IgM-IgM radioimmunoassay was developed for the immunodiagnosis of hepatitis B. The lower limit of this assay was approximately 100 pg +/- 30 (SEM) of HBsAg per ml of serum. Compared to available commercial radioassays, preliminary studies have shown the IgM-IgM assay to have increased sensitivity, which improved the detection of a HBsAg-associated determinant in acute hepatitis and post transfusion hepatitis. It is probable that the multivalent interaction between monoclonal IgM anti-HBs and the polydeterminant HBsAg is important in augmenting the performance of this monoclonal assay.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D019411:Clinical Laboratory Techniques; D006509:Hepatitis B / Q000175:diagnosis* / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D006801:Humans; D006822:Hybrid Cells / Q000276:immunology; D007075:Immunoglobulin M; D051379:Mice; D008807:Mice, Inbred BALB C; D011863:Radioimmunoassay / Q000379:methods
chemical_list: D006514:Hepatitis B Surface Antigens; D007075:Immunoglobulin M