非清髓性异基因造血干细胞移植后早期自然杀伤细胞的重建

 目的　研究非清髓性异基因造血干细胞移植（NAST）后早期自然杀伤（NK）细胞的重建情况。方法　分别用流式细胞术直接免疫荧光法、T细胞活化实验、四甲基偶氮唑蓝比色（MTT）法检测10例NAST后白血病患者及10位健康对照者细胞表面标志及体外免疫功能。结果　移植后28～35 d，患者外周血CD+3、CD+4细胞比例降低，分别为（2.03±15.60）%和（22.69±12.29）%，CD+8细胞比例正常或增高，平均为（29.26±8.99）%；T细胞对有丝分裂原反应减低，其增殖反应刺激指数为94.60±44.87；NK细胞比例在正常范围或增高，为（18.77±9.11）%；NK细胞表面IL-2R表达阳性率增高，平均为（3.71±2.23）%，和正常对照组的（2.05±0.94）%相比差异有统计学意义（t＝2.116，P＝0.044）；部分患者NK细胞活性明显增强，移植组与健康对照组分别为（25.30±12.39）%和（16.60±3.53）%（t＝2.135，P＝0.047）。结论　NK细胞在NAST后早期即恢复，当特异性免疫功能仍低下时，它可能在机体抗感染和抗肿瘤中发挥着重要作用。

Reconstitution of nature kill cell early after non-myeloablative allogeneic hematopoietic stem cell transplantation

Objective To study the reconstitution of nature kill cell early after non-myeloablative allogeneic stem cell transplantation （NAST）. Methods Cell phenotypes and in vitro immune functions were analyzed by direct immune fluorescence with FCM, T-cell activation test and MTT assay, respectively. Results The percentages of CD3^＋ CD4^＋ cells were low, （2.03±15.60） % and （22.69±12.29）%, respectively, while CD8^＋ lymphoeytes were normal or high [（29.26±8.99）%] ] month after NAST. Proliferative response to a T lymphocyte activator （PHA） was blunted, 94.60±44.87. The percentage of NK cells was within normal limits or high （n =7） in allotransplanted patients. It is （18.77±9.11） %, The percentage of CD56^＋ NK cells expressing IL-2R （CD25） was high and values obtained from transplanted patients were significantly different from control values . They are （3.71±2.23） % （t = 2.116, P = 0.044）. NK cell activity in part of patients was higher than that observed in control cells （25.30±12.39） % vs （16.60±3.53） % （t = 2.135, P = 0.047）. Conclusion NK cell has recovered early after transplantation and may be particularly relevant as a first line of defence in immunosurveillance against neoplastic cells or microbial infections, until a full reconstitution of T cell- mediated immune response can be achieved.