Objective: To detect the abnormal differentiation of bone marrow myeloid cells in myelodysplastic syndromes (MDS) and its correlation with the prognosis of MDS patients.
Methods: Quantitative assessment of CD11b, CD13, CD16 and HLA-DR expression on the membrane of bone marrow granulocytes, and CD71 and glycophorin A on erythroblasts of 12 MDS patients in low-risk, 22 in high-risk and 31 normal controls was conducted with flow cytometry. The correlation between the abnormality and the prognosis of MDS cases were analyzed.
Results: The granulocytic differentiation was analyzed with the combinations of CD13/CD11b, CD13/CD16 and CD11b/CD16. The "right hook", "sickle" and "retroflex 7" shape expressions were found in normal controls while there were various changes in MDS groups. The ratios of CD11b-/CD11b+ (0.39 +/- 0.34) and CD16-/CD16+ (1.33 +/- 0.77) were significantly higher in high-risk MDS group than those of control group (0.07 +/- 0.05 and 0.39 +/- 0.31 respectively) (P < 0.05). The MFI (mean fluorescence index) of SSC (side scatter) in the granulocyte gate of MDS groups was lower while MFI of CD13 was higher. The mean percentages of CD11b-HLA-DR+ 3.88% +/- 3.07%, CD11b-HLA-DR- 16.23% +/- 15.59%, CD16-HLA-DR- 41.12% +/- 24.53%, CD11b+CD16- 33.53% +/- 17.26% and CD13+CD16- 44.51% +/- 21.99% granulocytes of high-risk MDS group were significantly higher than those of low-risk and control groups (P < 0.05). The erythroid cell lineage differentiation was analyzed with CD71/glycophorin A combination. Double positive expression was found in all controls, but asynchronous expression of CD71/glycophorin A was found in some MDS cases. The mean percentage of double positive cells in CD45- and glycophorin A+ cell population was significantly lower in low-risk and high-risk MDS groups. The abnormal numbers and patterns of the antigen expression of MDS cases per case correlated directly with their IPSS (international prognostic scoring system) (r = 0.690, P = 0.000) and WPSS (WHO adapted prognostic scoring system) (r = 0.651, P = 0.000) scores.
Conclusion: There is an abnormal expression of differentiation antigens on bone marrow myeloid cells of MDS patients. And the severity is correlated with the prognosis. The abnormal differentiation of myeloid cells is probably involved in the pathogenesis of MDS. So the examination of these antigenic expressions with flow cytometry might be helpful for diagnosis and prognosis of MDS.