Ineffective hemopoiesis in the myelodysplastic syndromes (MDS) as studied by daily in situ observation of colony-cluster formation.

Daily in situ observation of individual proliferating cells was performed to examine ineffective hemopoiesis in vitro. Bone marrow mononuclear cells (BMMNC) from 24 myelodysplastic syndrome (MDS) patients and 12 controls were cultured for granulocyte-macrophage progenitor (CFU-gm) assays using methylcellulose. Individual proliferating cells were mapped at 3 days of culturing and their fates were followed by daily in situ cell counting contained within each cell aggregate until day 8. By retrospective analysis of the daily growth of the cells, a significantly greater proportion of noncolony-forming cells in MDS were found to proliferate initially, but failed to do so thereafter and degenerated in the culture. Cells showing these abnormal growth characteristics apparently contributed to ineffective granulopoiesis. The present method may be useful for clarifying ineffective granulopoiesis.