ANALYSIS OF MEGAKARYOCYTE GROWTH AND DEVELOPMENT FACTOR (THROMBOPOIETIN) EFFECTS ON BLAST CELL AND MEGAKARYOCYTE GROWTH IN MYELODYSPLASIA

Thrombocytopenia is a frequent feature of myelodysplastic syndromes (M DS) that could be improved by the use of recombinant,human. megakaryoc yte, growth and development factor (rHuMGDF). Using short-term liquid cultures and progenitor assays, we have found that rHuMGDF stimulated DNA synthesis and potentiated leukemic cluster growth of bone marrow m ononuclear cells in 10/38 MDS cases (26%). Cytogenetically malignant c olonies were detectable in rHuMGDF-stimulated cultures (n = 3) by fluo rescence in situ hybridization. rHuMGDF was able to stimulate CFU-MK f ormation in 45% of the samples tested. Finally, rHuMGDF-induced blast cell proliferation correlated with elevated expression of c-MPL, previ ously identified as a bad prognosis factor in MDS. (C) 1998 Elsevier S cience Ltd. All rights reserved.