In-vitro differentiation of myeloblasts from a patient with acute myeloid leukemia.

Although acute myeloid leukemia is characterized by defective granulocytic maturation in vivo, blasts from an occasional patient will differentiate in vitro. Leukemic myeloblasts from a 49-year-old woman who had acute myeloid leukemia were suspended in liquid culture containing McCoy's 5A medium with 15% fetal calf serum. Conditioned medium, prepared from normal human peripheral blood adherent cells incubated with 2-mercaptoethanol in McCoy's 5A medium with 15% fetal calf serum, was added to the cultures at a concentration of 40%. Within six days, cellular differentiation to polymorphonuclear granulocytes was observed. These cells were capable of phagocytosis. Attempts to induce differentiation of leukemic cells in liquid culture will, it is hoped, contribute to the understanding of defective cellular maturation in this disease.