Cell membrane antigens associated with human adult acute leukemia

Cell membrane antigens associated with the blast phase of human acute leukemia are separable from inhibitory proteins and from histocompatibility antigens also present in the membranes. Since these antigens are not detectable in remission or normal white blood cells, they provide a useful marker for identification of cells undergoing carcinomatous changes. Blast antigens from acute lymphatic leukemia (ALL) are also present on early human fetal thymus cells; antigens from both sources produce cell-mediated immune (CMI) responses and are structurally similar. Blast antigens from acute myelocytic leukemia (AML) are not associated with fetal antigens and do not cross react with ALL antigens. ALL cells possess a larger quantity of CMI inhibitory protein than AML cells. The isolation, purification and idenfication of these blast antigens is a step toward their use in studying cultured and cloned subpopulations of cells thought to be associated with pre-leukemia.