[Immunophenotypic and immunogenotypic analyses of acute leukemia and lymphoblastic lymphoma expressing myeloid and lymphoid antigens].

By using monoclonal antibodies against lymphoid and myeloid differentiation antigens, surface marker analysis was performed on the tumor cells from 42 patients with acute leukemia and lymphoblastic lymphoma. Nine (21%) of 42 cases were diagnosed biphenotypic leukemia. Two (17%) of the 12 patients with acute myeloid leukemia, four (18%) of 22 with acute lymphocytic leukemia and three (38%) of 8 with lymphoblastic lymphoma expressed both lymphoid and myeloid antigens. Tumor cells from six patients expressed both T-cell and myeloid antigens, and those from three other expressed both B-cell and myeloid antigens. Southern blot analysis was performed on the DNA from four patients with biphenotypic leukemia cells expressing T-cell and myeloid antigens. DNA from one patient showed clonal rearrangement of the immunoglobulin heavy chain (IgH) gene, and that from one other showed clonal rearrangement of both IgH gene and T-cell receptor beta-chain gene. DNA from two other patients showed a germline configuration of both genes. These results indicate that biphenotypic leukemia, especially T-cell and myeloid phenotype, is not so rare in acute leukemia and lymphoblastic lymphoma. The results of immunogenotypic analysis were not consistent with those of immunophenotypic analysis in biphenotypic leukemia.