肾移植急性排斥反应时B7-2/CD28信号通路的表达

背景:以往动物研究表明,在器官移植急性排斥反应时共刺激分子的表达与急性排斥反应密切相关.目的:观察急性排斥反应时患者移植肾脏组织和外周血中B7-2/CD28信号通路的表达.方法:对53例同种异体肾移植患者于移植前1 d、移植后1,3,7,14,21,28 d分别取外周血以及在临床诊断急性排斥反应当天和抗排斥治疗1周后额外采血,用流式细胞仪检测共刺激分子B7-2/CD28在外周血淋巴细胞中的表达;同时,行经皮肾穿刺活检供肾修整结束时、移植后7 d、1个月、6个月、1年或以上获取活检肾脏组织,用免疫组织化学方法检测活检组织中B7-2/CD28的表达情况.结果与结论:移植后1,3 d内所有患者外周血中CD28+,CD4+/CD28+,CD8+/CD28+细胞比率均有显著下降(P < 0.05),一二周后恢复到术前水平;移植后7 d未发生急性排斥反应的患者肾脏组织B7-2阳性表达率显著上升(P < 0.05),1个月后下降至移植前水平(P > 0.05).移植后发生急性排斥反应的患者外周血CD28+,CD4+/CD28+,CD8+/CD28+细胞比率及肾脏组织B7-2阳性表达率明显上升(P < 0.05),经抗排斥治疗1周后均好转.结果证实,在肾移植后出现急性排斥反应时,肾脏组织以及外周血中共刺激分子B7-2/CD28的表达上调与急性排斥反应的发生密切相关.

B7-2/CD28 expression in renal allograft recipients when acute rejection happens

BACKGROUND:The results of previous studies on animals indicate that the expression of co-stimulatory molecules in allograft recipients are relate to acute rejection of organs.OBJECTIVE:To observe the expression of B7-2/CD28 in peripheral blood samples and allograft renal biopsies of allograft recipients when acute rejection happened.METHODS:The peripheral blood samples of 53 cases were collected on 1 day pre-operative and 1,3,7,14,21 and 28 days postoperative,and were also collected during episodes of acute rejection and 1 week after treatment of acute rejection.The expression of B7-2/CD28 peripheral blood lymphocytes was examined by flow cyctometry.Allograft receptor’s renal biopsies were taken on pre-transplantation(at the cold ischaemia) and 7 days,1 and 6 months and 1 year postoperative.Immuohistochemical method was used to detect the expression of B7-2/CD28.RESULTS AND CONCLUSION:In the post-transplantation period,the number of CD28+,CD4+/CD28+,CD8+/CD28+ cells was decreased significantly within 1 and 3 days(P < 0.05),and then returned to pre-transplant levels by 1 to 2 weeks;increased expression of B7-2 cells was observed in the renal tissue without acute rejection at 7 days followed renal transplantation(P < 0.05),and then returned to the level of preoperative tissue after 1 month(P > 0.05).When acute rejection happened,the ratios of CD28+,CD4+/CD28+ and CD8+/CD28+ cells of peripheral blood samples and the expression of B7-2 in renal biopsies samples were significantly increased(P < 0.05) and returned to normal immediately after anti-rejection therapy for 1 week.The results show that the increased expression of co-stimulatory molecule B7-2/CD28 in allograft renal biopsies and peripheral blood samples of allograft recipients were closely relate to acute rejection after clinical renal transplantation.