Bone marrow S-phase is Associated with Risk assessment and Shows Differential Correlation with levels of CD34+ Blasts and CD16- Granulocytes in Patients with Myelodysplastic syndromes

IntroductionIncluding of proliferative parameters in the routine clinical flow-cytometry (FC) workup may be important for better evaluation of prognosis and risk assessment in patients with myelodysplastic syndromes (MDS). However, supportive data are still contradicting. AimTo assess the levels of FC based proliferative parameters in patients with MDS using propidium Iodide, and to study their correlation with risk assessment and the incidences of CD34+ blasts and CD16- and CD16+ granulocytes. MethodsData was retrospectively collected and analysed from 40 specimens of bone marrow (BM) aspiration of MDS patients, 14 specimens of hypocellular BM with no evidence of malignancy, and 16 specimens of reactive BM as determined by pathological examination. IPSS-R scores were calculated for MDS patients then divided to high-risk (IPSS-R score >4.5) and low-risk (IPSS-R score <3). The levels of proliferative parameters and their correlation with incidence of CD34+ blasts and CD16- and CD16+ granulocytes were compared between high and low risk MDS patients. ResultsMDS and reactive BM specimens showed similar whole sample S-phase percentage that was significantly higher than hypocellular BM specimens. As compared to MDS, reactive BM show a greater S-phase percentage in the erythroid fraction. In MDS, the whole sample S-phase percentage was significantly high in a subset of high-risk patients. Increased S-phase percentage in these patients was attributed to high S-phase percentage in granulocytes and monocytes. S-phase percentage correlated with the level of CD34+ blasts in the low-risk group but not in the high-risk group. In contrast to CD34+ blasts, the S-phase percentage correlated with the level of CD16- granulocytes in the high-risk group but not in the low-risk group. ConclusionsOur observations confirm the association of increased proliferative parameters and adverse prognosis in MDS, and suggest differential proliferation pattern of CD34+ and CD16- granulocytes in low and high-risk MDS patients.