Evidence for differentiation of human leukemic blood cells in diffusion chamber culture

Peripheral blood cells of 21 patients with different forms of acute leukemia were cultured in diffusion chambers (5 x 10(5) cells/chamber) implanted intraperitoneally in 650 R preirradiated host mice over a period of up to 21 days. In patients with acute myeloid leukemia (AML), acute erythroleukemia (AEL), or acute myelomonocytic leukemia (AMMoL), the total number of cells which developed during this culture period exceeded the implanted value and also the values for normal peripheral blood cells from ten controls. In acute undifferentiated leukemia (AUL), two out of six patients showed considerable growth whereas the others, and also two patients with acute lymphoid leukemia (ALL), had poor growth. Differential counts revealed that the rise in total cells was due mainly to proliferation of blast cells and formation of granulopoietic cells. The latter exceeded the numbers from normal peripheral blood cells in 9 out of 13 patients with AML, AEL, or AMMoL and in 2 out of 6 patients with ALL. The production of granulopoiesis was not restricted to proliferating cells, but included mature cells which were of abnormal morphology in some cases. From the amount of granulopoiesis and the time of its development it was assumed that they were at least partly derived from leukemic blast cells. Chromosome analyses to decide whether the granulopoietic cells were of leukemic or normal cell origin are in progress.