[Treatment of myelodysplastic syndromes with cytokines]

To evaluate the effects of colony-stimulating factors (CSFs) on pathological cells from myelodysplastic syndromes (MDS), CD34-positive cell fractions (mainly blast cells) from nineteen MDS patients and four normal volunteers were successfully enriched by the use of immunomagnetic beads, and their responsiveness to CSFs was examined in short-term liquid suspension cultures. Considerable parts of blast cells from MDS patients remained immature as compared with the favorable maturation of normal blast cells, especially in high-risk MDS group that included two prominent cases with a remarkable blast cell growth without maturation induction by CSFs. Short-term clinical administrations of G-CSF often brought about hematological improvements on MDS patients. Other cytokines are also reported to be of use on some patients. However, a few cases progressed to overt leukemia in relation to G-CSF treatment. Much care should be taken with in vivo application of CSFs to high-risk MDS patients, although there may be no effective clue to foresee the risk of leukemic transformation yet.