Patients with early stage myelodysplastic syndromes show increased frequency of CD4+CD25high+CD127low regulatory T-cells

Considering their potential ability to dampen the anti-tumor immunity, regulatory T-cells (Treg) have been often advocated as potential actors in the pathophysiology of several neoplastic diseases. This is particularly true in myelodysplastic syndromes (MDS), which are clonal hematologic disorders characterized by a marked immune dysregulation. We analyzed the frequencies of Treg in a cohort of 36 patients with early stage myelodysplastic syndromes (MDS), by using a flow cytometry approach based on the concomitant expression of CD25 and CD127. MDS patients showed a higher frequency of CD4+CD25high+CD127low Treg than healthy controls (1,51% vs. 1,14%), with no specific influences from patient- and disease-related factors. Our data could reflect the existence, even in early stage MDS, of an impairment of the anti-tumor immunity which has already been observed in other clonal disorders.