[Four-color flow cytometric immunophenotypic features of blasts in myelodysplastic syndromes]

This study was aimed at exploring the immunophenotypic features of blasts in patients with myelodysplastic syndromes (MDS). Four-color flow cytometry using conventional and secondary gating strategies was used to immunophenotype blasts and the CD34 positive cells in bone marrow nucleated cells of 29 patients with MDS. The results showed: (1) with progression of MDS from RA/RAS, RAEB to RAEB-T, the proportion of CD34(+) cells were gradually increased from 8.0%, 46.4% to 76.8% (P < 0.05); (2) using CD45 vs SSC gating strategy, with the transformation of RA/RAS, RAEB to RAEB-T, the expression of HLA-DR, CD13, CD33, CD117 were also gradually increased (P < 0.05), and the expression of CD15 was gradually decreased (P < 0.05); (3) using CD45 vs CD34 gating strategy, the expression of HLA-DR, CD13, CD33, CD117 on blasts were higher by secondary gating method than those by conventional gating (P < 0.05). However, there were no significant difference (P > 0.05) in the expression of above-mentioned antigens on CD34(+) cells among different MDS subtypes. It is concluded that conventional gating method can reflect MDS progression from RA/RAS, RAEB to RAEB-T, and secondary gating strategy may accurately reflect the biological features of blasts in MDS. Abnormal expression of CD34 is related to the immaturity level and heterogeneity of blast cells, which is beneficial to the diagnosis of clinically suspected MDS incapable of diagnosing with morphology and cytogenetics.