Monoclonal antibodies reactive with acute myelogenous leukemia cells.

Two cytotoxic monoclonal antibodies (D5D6 and C10H5) were raised to acute myelogenous leukemia (AML) cells. One of them, D5D6, reacted with 100% of the cells from 44/50 AML patients. The second, C10H5, reacted with 100% of the cells from 13/39 AML patients. D5D6 and C10H5 were cytotoxic to 100% of the monocytes from all healthy donors tested. Apart from monocytes, these antibodies did not react with any other peripheral blood cells from normal donors or with cancerous cells either from cell culture lines or from patients with chronic myelogenous leukemia (CML), lymphoid leukemias, or solid tumors. These antibodies inhibited the growth of the myeloid-monocytic stem cell, the CFU-C, and reacted with a minor population of normal bone marrow cells by immunofluorescence. Both D5D6 and CH5 have potential utility for the differential diagnosis of acute leukemia, for the detection of early leukemic relapse, and for enrichment of human stem cells.