Changes and significance of CD4+ CD25+ regulatory T cells and serum interleukin-10 in myelodysplastic syndrome patients

Objective To study the changes and significance of CD4+ CD25+ regulatory T cells (Treg) and serum interleukin (IL)-10 in myelodysplastic syndrome (MDS) patients. Methods From October 2010 to December 2012, a total of 23 cases of MDS patients who were newly diagnosed in Department of Hematology, Xinghua People's Hospital of Jiangsu Province were included into this study, as study group (n=23). And they were divided into four subgroups according to the International Prognostic Scoring System (IPSS), high risk group (n=5), medium risk-Ⅰ group (n=11), medium risk-Ⅱ group (n=4) and low risk group (n=3). During the same period and in the same hospital, a total of 10 cases of non-malignant immune hematologic diseases patients, such as iron deficiency anemia and megaloblastic anemia were chose as control group (n=10). All patients in study group and control group, their CD4+ CD25+ Treg and serum IL-10 were detected by flow cytometry and enzyme linked immunosorbent assay (ELISA), respectively, and then they were analyzed by statistical methods. There were no significant differences of patients' general clinical features between two groups and subgroup, respectively(P>0.05).The study protocol was approved by the Ethical Review Board of Investigation in Human Being of Xinghua People's Hospital of Jiangsu Province. Informed consent was obtained from all patients. Results ① The percentage of CD4＋CD25＋Treg and serum IL-10 expression level in study group were (6.89±1.28)% and (7.02±1.83) μg/L, respectively, which were significantly higher than those of control group (2.72±0.46)% and (3.72±1.76) μg/L, and the differences were statistically significant (t＝5.263, 3.824; P 0.05). But the CD4＋CD25＋Treg percentage and IL-10 expression level compared between low-risk group and moderate Ⅱ group, low-risk group and high-risk group, moderate Ⅰ group and moderate Ⅱ group, and between moderate Ⅰ group and high-risk group, the differences were all statistically significant (P<0.05). ③ There were positive correlations between peripheral blood CD4＋CD25＋Treg percentage and serum IL-10 expression level of MDS patients (r＝0.326, P＝0.326). Conclusions The number of CD4＋CD25＋Treg and (or) its function imbalance plays an important role in the occurrence and development of MDS, and the percentage of CD4＋CD25＋Treg and serum IL-10 expression levels increase along with the growth of prognostic risk, suggesting that abnormal immunity is a contributing factor to the occurrence and development of MDS. So the CD4＋CD25＋Treg might be a new target for targeted immune therapy of MDS. Key words: Myelodysplastic syndromes; CD4+ CD25+ T-lymphocytes, regulatory; Interleukin-10