慢性髓细胞白血病异基因外周血联合骨髓造血干细胞移植后NK细胞及受体谱重建的研究

Study of NK cells and NK cell receptor repertoire reconstitution in patients with chronic myeloid leukemia following allogenetic peripheral blood stem cell combined with bone marrow transplantation

目的观察慢性髓细胞白血病（CML）患者进行异基因外周血联合骨髓造血干细胞移植（allo—PBSCT＋BMT）后NK细胞及其受体谱重建的规律。方法11例CML患者采用同胞异基因HLA6／6位点相合的allo—PBSCT＋BMT，使用流式细胞术检测移植后受者不同时间的NK细胞及其受体谱的变化和重建的规律。结果NK细胞在早期造血重建时就开始重建并很快达到正常值水平，移植30d NK细胞绝对值达到高峰，约占淋巴细胞的（37．1±7．06）％，后逐渐下降，移植120d比例基本正常。植入时CD3^-CD56^bright细胞占淋巴细胞的（3．6±1．25）％，移植30d时CD3^-CD56^bright细胞短暂上升，占淋巴细胞的（8．3±4．13）％左右，移植60d CD3^-CD56^bright细胞基本稳定在正常水平。CD94在移植后1年始终处于高水平，NKG2A在植入时占淋巴细胞的（90．3±5．35）％，移植60d后下降到（45．8±12．36）％，而NKG2D迅速由植入时的（36．7±14．33）％上升到移植60d的（82．3±8．64）％，NKP46在移植30～90d下降较快。CD158a、CD158b植入时表达较低，CD158b逐渐上升，移植60d达到淋巴细胞的（58．5±6．58）％，CD158a始终在低水平。结论相对于其他移植方式，allo—PBSCT＋BMT后NK细胞比例可能略少，但是成熟较早，可能发挥重要的移植物抗白血病效应及诱导免疫耐受作用。

Objective To observe the NK cells and NK cell receptor repertoire reconstitution after allogenetic peripheral blood stem cell combined with bone marrow transplantation （ allo-PBSCT ＋ BMT） in chronic myeloid leukemia （ CML ） patients. Methods Flow Cytometer was used to measure NK cells and NK cell receptor repertoire reconstitution of 11 CML patients following HLA 6/6 coincidence allo-PBSCT ＋ BMT in different intervals. Results NK cells reached normal level while engraftment and ascended to peak at 30 days after 30 days transplantation and then kept steady after 120 d. NKP46 reached （ 92.1 ± 33.65 ） % of NK cells at 30 d. NKG2D was （ 36.7 ± 14.33 ） % of NK cells when engraftment and it ascended thereafter and it reached normal at 60 d. NKG2A was at a high level[ （90.3 ±15.35） % ]of NK cells when engraftment but it descended quickly at 60 d [ （48.5 ± 12.36） % ], CD158a was at a low level the whole year along after transplantation. CD158b was at a normal level when engraftment and it ascended gradually and reached （ 58.5± 6.58 ） % at 60 d. CD94 maintained a high level in whole year after transplantation. Conclusion NK cells and NK cell receptor repertoire may be of much importance,like GVL and inducing immunotolerance, after allo-PBSCT ＋ BMT although NK cells and its receptor repertoire account a little percentage while they mature earlier.