Human acute myelogenous leukemia antigens defined by simian antisera: evidence for leukemia-associated antigens distinct from immune response-associated alloantigens

Leukemic blasts from a patient with acute myelogenous leukemia (AML) and peripheral blood T- and B-lymphocyte subpopulations from his genetically identical normal twin were analyzed with the use of the simian antiserum-defining AML antigens and a rabbit antiserum to immune response-associated (la)-like antigens. Blast cells from the patient consistently reacted with both reagents, whereas the B-lymphocyte populations from the patient's normal identical twin reacted only with the rabbit anti-la serum and in no instances reacted with the antiserum to AML cell antigens. Blast cells from the AML patient significantly stimulated the lymphocytes of his normal twin and his own remission leukocytes, whereas the cells from the normal twin failed to stimulate the cells of the patient. These results suggested the existence on AML cells of tumor-associated antigens that are distinct from various other well-characterized normal human alloantigens and differentiation antigens including B-cell antigens. Changes were reported in the expression of leukemia-associated antigens and Ia-like antigens on the cells of an AML patient undergoing chemotherapy as well as in the ability of the simian antisera to distinguish antigens specific for myeloid leukemias from lymphocytic types of leukemias.