Agar cultures of blood and marrow cells were used to determine the nature and frequency of granulocytic progenitor cells (in vitro colony-forming cells) in 133 patients with various hematologic diseases, including 33 with acute and 17 with chronic myeloid or myelomonocytic leukemia. Cultures from patients with acute myeloid leukemia (AML) in relapse or in the acute transformation phase of chronic myeloid leukemia (CML) were characterized by lack of normal colony formation and either complete absence of in vitro proliferative capacity or production of large numbers of small clusters composed of poorly differentiated cells. Patients with CML had greatly increased numbers of colony-forming cells particularly in the blood, and these were identified as myeloblast-like cells with a cloning efficiency of at least 60%.

No abstract

No abstract

No abstract