title: An antigen common to chronic lymphocytic and hairy cell leukemia cells not shared by normal lymphocytes or by other leukemic cells.
abstract: Rabbit xenoantisera and mouse monoclonal antibodies prepared against human chronic lymphocytic leukemia (CLL) B cells were found to react against a single polypeptide chain with a mol wt of 69 kd found on leukemic cells of all CLL (N = 40) and B type hairy cell leukemia (HCL) patients (N = 9) examined. This common CLL-associated antigen (cCLLa) was not detectable on circulating T or B lymphocytes, thymocytes, lymph node and splenic lymphocytes, or bone marrow leukocytes from normal persons. In addition, the cCLLa was not detectable on cultured T or B lymphoblastoid cell lines or on malignant cells from other forms of lymphocytic or myelocytic leukemia. Non-Hodgkin's lymphoma cells also failed to express the antigen. Autologous cultured lymphoblastoid cell lines were established from residual normal B cells from a CLL patient whose cells were used to generate one of the antisera. Absorption of the antibody with these cultured polyclonal B cells did not affect the anti-CLL activity, which suggests that the cCLLa is not HLA related. Unlike the T cell differentiation complex gp65-71, the cCLLa was not expressed on fetal or cord blood lymphocytes or on mitogen-stimulated normal lymphocytes and was distinct from the antigen recognized by the LEU-1 antibody in spite of their similar mol wt. The cCLLa was also determined to be unrelated to the human T cell leukemia lymphoma virus (HTLV-1). One of the monoclonal antibodies generated against the cCLLa was a complement binding IgG which exhibited highly selective cytotoxic activity against 100% of cells bearing the cCLLa. Such an antibody might prove clinically useful in early diagnosis and treatment of CLL and HCL.
mesh_terms: D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D000951:Antigens, Neoplasm / Q000032:analysis*; D001402:B-Lymphocytes / Q000276:immunology; D003602:Cytotoxicity, Immunologic; D006801:Humans; D007943:Leukemia, Hairy Cell / Q000175:diagnosis / Q000276:immunology*; D007945:Leukemia, Lymphoid / Q000175:diagnosis / Q000276:immunology*; D015260:Neprilysin; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D015260:Neprilysin