title: Increased levels of circulating HLA-DR antigen in sera of patients with acute lymphoblastoid leukemia.
abstract: Monoclonal antibodies that define HLA-DR antigen bind to a variety of human tumors, such as Burkitt lymphoma and melanoma cells grown in vitro and with the spent medium of these cultures. Two radioimmunoassays have been developed to detect HLA-DR antigen circulating in human sera. The inhibition assay is based on the inhibition of binding of monoclonal antibodies against HLA-DR to the target preparation; the double-determinant assay traces antigen bound by a solid-phase monoclonal antibody by the use of a second 125I-labeled antibody. Twenty-six of 39 sera from patients with acute lymphoblastoid leukemia, 2 of 29 sera from patients with acute myeloid leukemia, and 5 of 31 sera from patients with advanced metastatic melanoma showed increased levels of HLA-DR antigen, whereas none of 28 sera from patients with other malignancies had increased levels of HLA-DR antigen, and only 2 of 155 sera from healthy donors bound monoclonal antibodies to HLA-DR at detectable levels. The detection of circulating HLA-DR antigen in sera of cancer patients may be useful in monitoring patients with certain malignancies.
mesh_terms: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D002460:Cell Line; D005260:Female; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II / Q000032:analysis*; D006801:Humans; D007118:Immunoassay; D005779:Immunodiffusion; D007945:Leukemia, Lymphoid / Q000276:immunology*; D008297:Male; D008545:Melanoma / Q000276:immunology; D009369:Neoplasms / Q000276:immunology; D012016:Reference Values
chemical_list: D000911:Antibodies, Monoclonal; D000936:Antigen-Antibody Complex; D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II