BACKGROUND: AIIograft rejection is the greatest obstacle that influences graft function and survival, and the diagnosis and treatment of small intestine transplantation rejection are particularly difficult.OBJECTIVE: To explore the significance of chemokine receptor antagonist, Met-RANTES, in small intestine transplantation rejection, and the effects of tacrolimus (FK506) on RANTES expression.DESIGN, TIME AND SETTING: Randomized, controlled animal experiment was performed at the Department of General Surgery, the 451 Hospital of Chinese PLA; Laboratory of Department of Gastrointestinal Surgery, Xijing Hospital, Fourth Military Medical University of Chinese PLA; and Electronic Microscope Center, School of Basic Medicine, Fourth Military Medical University of Chinese PLA between September 2003 and March 2005.MATERIALS: A total of 72 healthy adult male SD rats (donor) and 72 healthy adult male Wistar rats (recipient) were included for heterotopic small intestine transplantation.METHODS: Heterotopic small intestine transplantation was performed. All recipients were divided into four groups (n=18): intact control group: Wistar rats as controls with no surgery; isotransplantation group: Wistar--,Wistar; allotransplantation untreated group: SD→Wistar, with no immunosuppressive agent; allograft allotransplantation and FK-506 group: SD→Wistar + FK-506 (1 mg/kg per day, i.m. for 7 days). The grafts were sampled on postoperative days 3, 5 and 7 and were examined pathologically. Successive quantitative measurement was conducted to detect the expression of graft RANTES with immunofluorescence staining and laser scanning confocal microscope technique.MAIN OUTCOME MEASURES: The pathological changes of grafts in each group; RANTES expressions in small intestine grafts of rats in each group at different time points; inhibition of FK-506 on RANTE expression.RESULTS: Postoperatively, 72 Wistar rats (recipient) were involved in the final analysis. The pathological changes of the allotransplantation untreated group rats were consistent with the criteria of mild, moderate and severe rejection on postoperative days 3, 5 and 7, respectively. No obvious rejection was found in the rats of FK506 group and isotransplantation group on the postoperative days 3, 5 and 7. Expression of intragraft RANTES of allotransplantation untreated group rats was significantly greater than the other three groups (P<0.01). The dynamic change and the process of acute rejection showed positive correlation. Expression of intragraft RANTES in FK-506 treated group was significantly less than other three groups without FK-506 (P<0.01).CONCLUSION: RANTES positive cells play an important role in small intestine allograft rejection. Dynamic observation on expression of intragraft RANTES may act as a predicator for diagnosing acute allograft rejection.%背景:同种异体移植排斥反应是影响移植物功能和存活的最大障碍,小肠移植排斥反应的诊断与治疗尤为困难.目的:探讨移植肠RANTES的表达在小肠移植急性排斥反应中的意义,以及他克莫司对它的影响.设计、时间及地点:随机对照动物实验,于2003-09/2005-03在解放军第四五一医院普通外科、解放军第四军医大学附属西京医院胃肠外科实验室、解放军第四军医大学基础部电子显微镜中心为大专院校的实验室完成.材料:选用健康成年雄性SD和Wistar大鼠各72只.以SD大鼠为供者,Wistar大鼠为受者,施行异位小肠移植.方法:实施大鼠异位小肠移植,按照不同品系的组合将移植大鼠分为4组(n=18):非手术对照组,Wistar大鼠作为正常对照,不实施小肠移植;同基因移植组,将Wistar大鼠的小肠移植给同品系的Wistar大鼠;异基因移植未治疗组,将SD大鼠的小肠移植给Wistar大鼠,移植后不给予免疫抑制剂治疗;异基因移植他克莫司治疗组,将SD大鼠的小肠移植给Wistar大鼠,移植后0～7 d肌肉注射他克莫司,1 mg/(kg·d).移植后3,5,7 d每组各处死6只大鼠,切墩移植肠标本进行组织病理学检查,并采用免疫荧光染色和激光扫描共聚焦显微镜技术对移植肠RANTES的表达进行连续定量测定.主要观察指标:①各组大鼠移植肠的组织病理学改变.②不同时间点移植物内RANTES阳性细胞的表达变化.③他克莫司对异基因移植大鼠移植肠RANTES表达的抑制作用.结果:72只受体大鼠均进入结果分析.异基因移植末治疗组大鼠后3,5,7 d移植肠符合轻、中、重度急性排斥反应的病理学诊断标准;他克莫司治疗组大鼠和同基因移植对照组大鼠在观察期内未发现明显排斥反应征象.异基因移植未治疗组大鼠的移植肠RANTES表达在术后均显著高于其他3组(P<0.01),其动态变化与急性排斥反应的进程呈正相关;他克莫司治疗组大鼠移植肠RANTES的表达明显低于未治疗组(P<0.01).结论:RANTES阳性细胞在小肠移植急性排斥反应中发挥了重要作用,动态检测移植肠RANTES的表达变化,可能成为小肠移植急性排斥反应有效的诊断指标之一.
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