中文摘要：

目的分析β重型地中海贫血儿童NK细胞频率及杀伤活性与输血诱导的免疫抑制的相关性。方法收集2011年1月～2013年12月在广州市妇女儿童医疗中心及中山大学附属第三医院进行输血治疗长达3年的β重型地中海贫血儿童20例（β重型地中海贫血组）及健康儿童20例（对照组）,通过流式细胞技术检测其外周血NK细胞（CD3-CD56＋）的频率及NK细胞杀伤活性（CD107a表达）。结果与对照组比较,长期输血的β重型地中海贫血组儿童外周血NK细胞频率显著降低[（4.5±2.8）%比（12.0±4.0）%],差异有统高度计学意义（P=0.000）。外周血CD107a表达（NK细胞的杀伤活性）显著下调[（23.9±7.4）%比（51.4±11.9）%],差异有统高度计学意义（P=0.000）。结论β重型地中海贫血组儿童外周血NK细胞频率的减少及NK细胞杀伤活性（CD107a表达）的减弱,可能与输血诱导的免疫抑制相关。

英文摘要：

Objective To analyze the association between the frequency and cytotoxicity of peripheral NK cells in β-thalassemia major children with the transfusion-induced immunodepression. Methods From January 2011 to December2013, in Women and Children＇s Medical Center of Guangzhou City and the Third Affiliated Hospital of Sun Yat-sen University, the peripheral blood samples of 20 cases of β-thalassemia major children with 3 years blood transfusion（β-thalassemia major group） and 20 healthy children（control group） were obtained. The frequency of peripheral NK cells（CD3-CD56＋） and CD107a expression on surface of peripheral NK cells were detected by flow cytometry. Results The proportion of peripheral NK cells of children with β-thalassemia major was markedly decreased than that of the control group [（4.5±2.8）% vs（12.0±4.0）%], the difference was statistically significant（P = 0.000）. The expression of CD107a on the surface of CD3-CD56＋NK cells from patients with β-thalassemia major was remarkably down regulated than that of the control group [（23.9±7.4）% vs（51.4±11.9）%],the difference was statistically significant（P = 0.000）.Conclusion The decreased frequency and the cytotoxicity（CD107a expression） of NK cells in β-thalassemia major may contribute to the transfusion-induced immunodepression.