Using Multiparametric Flow Cytometry to Analysis the Immunophenotypic Abnormalities of Bone Marrow Cells in Patients with MDS-RAEB.

The multiparametric flow cytometry is becoming a very useful tool of the diagnosis and prognostication for patients with Myelodysplastic Syndrome(MDS). This study was aimed at using multiparametric flow cytometry to explore the immunophenotypic abnormalities of bone marrow cells from patients with RAEB.

We collected BM samples from 12 MDS-RAEB patients (6 male, 6 female, Median Age 67.5) and 20 non-MDS patients (11 male, 9 female, median age 32.5, 7 AA, 5 PNH, 3 IDA, 1 ALL, 2 CML, 2 MM). The multiparametric flow cytometric analysis was performed using an extensive panel of monoclonal antibodies. We used the conventional and secondary gating strategies to analysis the BM cells compartments such as the percents of blast cells and the expression of lineage and maturation-associated antigens of BM hemopoietic cells quantified.

Compared with the non-MDS group, the proportion of blast cells increased significantly in the MDS-RAEB group (P=0.001), but the percentages of nucleated erythrocyte, lymphocyte, monocyte and granulocyte were no significant difference (P=0.954, P=0.893, P=0.730 and P=0.182). As the percentage of blasts cells increasing, the survival time became shorter (13 ± 6 vs 35 ± 15 months; P=0.02). The expressions of haemopoietic stem/progenitor cell surface marker CD34+ and T lymphocyte surface marker CD7+ on blast cells were much higher by secondary gating method than non-MDS group (P=0.009, P=0.002, respectively), while no significant difference of the expression of CD56 (P=0.375). The expressions of CD7+ and CD56+ on lymphocyte were no significant difference between the two groups (P=0.195, P=0.369, respectively), however the expression of CD19+ may be different (P=0.039). The expressions of CD33+ and CD13+ on granulocyte were no significant difference between the two groups (P=0.289, P=0.744, respectively). However, the expression levels of CD15+CD11b+, CD15+CD11b-, CD10+, HLA-DR, CD56+ in the MDS-RAEB group were significantly higher than those in the non-MDS group, specially, the levels of CD10+, HLA-DR and CD56+ were much higher (P=0.016, P=0.011, P=0.005, P=0.005 and P=0.005, respectively) and these patients showed a shorter median overall survival (15 ± 5 vs 36 ± 10 months; p = 0.03).

The percentage of blast cells increased in MDS-RAEB patients and the expressions of CD34+, CD7+ on blast cells and the expressions of CD10+, HLA-DR and CD56+ on granulocyte is higher than non-MDS group. It will be necessary to increase the number of cases (MDS-RAEB) to confirm our findings. Using multiparametric flow cytometry can find the immunophenotypic abnormalities more sensitively, accurately and objectively, and this new approach could provide much more useful information in the diagnosis and prognosis of MDS-RAEB patients.

No relevant conflicts of interest to declare.