特发性血小板减少性紫癜患儿外周血T细胞PKC活性检测及临床意义

Study on changes of protein kinase C activity in peripheral blood T lymphocytes of children with idiopathic thrombocytopenic purpura and its clinical significance

目的检测ITP患儿外周血T细胞蛋白激酶C(PKC)的活性变化,探讨其与T细胞活化和血小板损伤之间的关系。方法取35例ITP患儿及30例正常儿童外周血,用T细胞富集柱法分离纯化T细胞,分别用非同位素标记法检测T细胞PKC活性,用流式细胞仪检测T细胞活化标志FasL的表达,血液分析仪计数血小板。结果ITP患儿T细胞PKC的总活性较正常儿童明显增强(0.97±0.21nmol/min·ml-1vs0.60±0.13nmol/min·ml-1,P<0.05),FasL表达较正常儿童显著升高[(CD4+TFasL:(32.7±3.4)%vs(14.7±4.2)%;CD8+TFasL:(17.3±9.7)%vs(11.6±8.5)%,P<0.05],T细胞PKC的活性变化与FasL的表达呈正相关(r1=0.48,r2=0.33,P<0.05),与血小板计数呈负相关(r=-0.55,P<0.05)。结论ITP患儿外周血T细胞PKC活性增强,T细胞活化,并伴有血小板数量减少,提示PKC信号传导在ITP的发病机制中可能起作用。

Objective To investigate the changes of protein kinase C （ PKC ） activity in peripheral blood T lymphocytes of the children with idiopathic thrombocytopenic purpura （ITP） and the relationships between PKC activity and T lymphocytes activation and thrombo- cyte decrease. Methods Sterilized peripheral blood were collected from ITP children （ n = 35 ） and healthy children （ n = 30 ）. T lymphocytes were isolated and purified by the T cell segregation enrichment column. The total PKC activity was detected by non-radioactive assay. FasL,the T cell activated marker, was determined by flow cytometer. Platelet count was performed by hematocytometer. Result Compared with healthy children, total PKC activity in ITP children was significantly enhanced （0.97 ± 0.21 nmol/min, ml vs 0.60 ± 0.13 nmol/min, ml, ^-x±s ,P 〈 0.05 ）. Expression of FasL on T cell subpopulation of ITP patients was significantly increased （ FasL on CD4^＋ T cell ：32.7 ± 3.4% vs 14.7 ± 4.2% , FasL on C D8^＋ T cell ： 14.3 ± 9.7 % vs 11.6 ± 8.5 % , ^-x± s,P 〈 0.05 ）. Besides, the relationship between the changes of PKC activity and FasL expression was positive correlation （ r^1 = 0.48,r^2 = 0.33,P 〈 0.05 ） , however, the relationship between PKC activity and platelet count was significantly negative correlation（ r = -0.55 ,P 〈 0. 05 ）. Conclusion Enhancements of PKC activity in ITP children may result in T lymphocytes activation and reduction of thrombocytes, which indicate that PKC signal transduction way may play an important role in the immunopathogenesis of ITP.