Expression And Significance Of CD4~+CD25~+Regulatory T Cells In Primary Immune Thrombocytopenia

Primary immune thrombocytopenia (ITP) is a bleeding syndrome characterized bythe increase of blood platelet destruction and the decrease of platelet quantity which ismediated by immunity disorders. Its pathogenesis is still unclear, both of the cellularimmunity and humoral immunity may be the important causes of ITP. CD4~+CD25~+regulatory T cells (Treg) are immuno-regulation cells which have the functions relatedto anergy and immunosuppression. They play an important role in the peripheralimmune tolerance. The decreased amount of these cells and their weakenedimmuno-regulating function may be highly associated with ITP morbidity.Object: The aim of this study was to explore the expression and significance ofCD4~+CD25~+regulatory T cells in primary immune thrombocytopenia.Method: Thirty-three patients diagnosed with ITP and20health controls were studied.The expression of CD4~+CD25highand CD4~+CD25~+CD127dimregulatory T cells weredetected by flow cytomtery. All of ITP patients were further divided into two groupsincluding serious patients and mild patients. According to the amount ofmegakaryocytes, they were also divided into two groups, the significant increased groupand non significant increased group. ITP patients with post-treatment were furtherdivided into two groups with effective and ineffective treatment patients. Statisticalanalysis was carried out with regard to data in different groups. Result: Before treatment, the levels of CD4~+CD25highand CD4~+CD25~+CD127dimregulatory T cells in ITP group patients are (1.54±0.13)%and (3.31±0.38)%respectively,which are both significantly lower than health group (2.44±0.34)%and(5.47±0.80)%respectively (P<0.01). And the levels of these two category are higher inthe group that MK amount is significant increased (1.60±0.12)%and (3.48±0.45)%respectively than in non significant increased MK amount group (1.45±0.13)%and(3.08±0.33）%respectively. The levels of CD4~+CD25highand CD4~+CD25~+CD127dimregulatory T cells in serious group patients and mild group are (1.48±0.12,3.19±0.37)%and (1.61±0.11，3.47±0.34）%respectively, while the levels of serious group aremarkedly lower than that of mild group(P<0.01, P<0.05). The post-treatment patients’levels of CD4~+CD25highand CD4~+CD25~+CD127dimregulatory T cells are (2.01±0.22)%and (4.70±0.28)%respectively, which are both significantly higher than before.Thelevels of CD4~+CD25highand CD4~+CD25~+CD127dimregulatory T cells in effectivetreatment group patients are（2.05±0.20，4.80±0.23）%and（1.91±0.15，4.54±0.32）%respectively，while the levels of effective treatment group are significantly higherthan that of ineffective group (P<0.05). All the results in our research have statisticalsignificances.Conclusion: The expression of Treg cells has an important clinical significance in thepathogenesis and progression of ITP. The expression of Treg cells can probably be asensitivity index for judging the severity degree of ITP patient’s condition, monitoringthe treatment effect and evaluating the prognosis.