Changes in hemopoietic precursors after treatment of low-risk myelodysplasia with amifostine.

BACKGROUND: Clinical studies have shown that amifostine (AMF) improves peripheral cytopenias in myelodysplastic syndromes (MDS). We studied the expression of Fas/FasL on CD34+ cells in low risk MDS and its change after AMF treatment. PATIENTS AND METHODS: Patients received AMF 400 mg/m2 3x/week for 3 weeks and 2 weeks off treatment. Peripheral blood counts and BM cytology were analysed before and after 2 courses. Quantification of CD34+ cells and CD34/CD95 and CD34/CD95L ones were performed by flow cytometry. RESULTS: Seventeen patients were treated. After 2 months, 8 patients showed a rise in neutrophil count. Hemoglobin increased in 1 and thrombocytes in 2 patients. Before treatment, responding patients presented a significantly lower expression of Fas (median 53%) and FasL (median 26%) than non-responders (85% and 70%, respectively). BM lymphocytes were significantly lower in responders (median 14.5% and 27.4%, respectively). In responders CD34+ cells decreased after treatment. The change in neutrophil count after treatment presented an inverse correlation with the percentage of BM lymphocytes before treatment (r = 0.0-0.58; p = 0.02). CONCLUSION: Response to AMF may be influenced by the intensity of the immune reaction in BM.