Characterization of novel myeloid differentiation antigen associated with acute myelogenous leukemia

A monoclonal antibody has been developed that detects a unique cell surface antigen (NHL-30.5) with a molecular weight of 180,000 expressed on the human acute promyelocytic cell line HL-60. In addition to HL-60 and other AML cell lines, the antibody reacts with a significant proportion of hemopoietic cells from 40/48 patients with acute myeloid leukemia (AML), and on a variety of other hematologic disorders characterized by the presence of immature myeloid blast cells. In contrast it does not react with normal mature hemopoietic cells, including lymphocytes, monocytes, granulocytes, erythrocytes, platelets, and splenocytes. Only one of 15 acute lymphoblastic leukemias has demonstrated reactivity (weakly) and all lymphoid cell lines tested have been uniformly negative. Reactivity with cells from patients in the chronic phase of chronic myeloid leukemia (CML) is also rare (7/26) and the number of NHL-30.5 positive cells is low (