Response of hematopoietic precursor cells to hematopoietic growth factors in the myelodysplastic syndromes.

The in vitro effects of 4 recombinant hematopoietic growth factors on myelodysplastic syndrome cells from 22 patients were assessed by colony assays (CFU-GM, BFU-E). DNA synthesis, cytological and cell phenotypic studies. Growth factors seemed to be potent stimulators on cell proliferation, but showed only limited effects on cell differentiation. Combinations of factors were more efficient than factors used alone. Nevertheless, culture growth patterns remained abnormal. Cell proliferation was major in the cases with excess of blasts with, in 2 cases, stimulation of leukemic cells.