Clinical course of myelodysplastic syndromes.

The myelodysplastic syndromes are a heterogeneous group of disease states ranging from relatively benign to aggressive forms. It is now possible to specify factors with prognostic value. Poor-prognosis factors that can easily be assessed are (1) bone marrow blasts exceeding 5% of the nucleated cells, (2) the presence of blast cells in the peripheral blood, (3) pancytopenia, and (4) a high Bournemouth, FAB, Düsseldorf, or Spanish score. Further important poor-prognosis features are (5) the presence of karyotypic abnormalities, (6) the finding of ALIP, and (7) a leukemic pattern of in vitro progenitor cell growth. The assessment of the value of therapeutic intervention either by treatment with hematopoietic growth factors or by chemotherapy will require the knowledge of the distribution of these features.