骨髓干细胞输注联合低剂量他克莫司在肾移植中诱导嵌合体的形成

Bone marrow stem cells combined with low-dose tacrolimus induce chimera formation following renal transplantation

背景:骨髓细胞嵌合体通过有效的免疫耐受机制,使其成为临床用于移植免疫耐受的主要候选方法。目的:探讨大鼠肾移植及活体肾移植中骨髓干细胞移植对免疫耐受的诱导作用及机制。方法:①大鼠肾移植:40只Wistar大鼠(雌雄各半)随机分为实验组和对照组,进行肾移植手术,术前经门静脉分别注射骨髓干细胞及生理盐水,30d后观察肉眼和光镜下排斥反应及检测嵌合体的形成。②活体肾移植:实验组为夫妻或亲属共5对,供者均为男性,受者为女性。术前应用他克莫司口服,供者皮下注射生白细胞药物,采集白细胞悬浊液,以流式细胞仪测定CD34细胞比例,0.7%以上为骨髓干细胞含量合格,并通过外周静脉输注至受者体内,10d后同法再输注1次,1周内行移植手术,术后复查肾功,于半年后采用荧光原位杂交的方法检测Y基因片段。对照组为正常活体肾移植手术,未行骨髓干细胞移植。结果与结论:动物实验组大体和光镜下排斥反应均较轻微,嵌合体检测均为阳性,活体实验组嵌合体检测4例为阳性,而对照组仅1例为阳性。提示应用他克莫司并输注供者骨髓干细胞,可诱导一定的免疫耐受。移植前输注供者骨髓干细胞形成的嵌合体与免疫耐受有关。

BACKGROUND：The bone marrow cells are candidate approaches for inducing immunological tolerance.OBJECTIVE：To explore effects of bone marrow cell transplantation on immunological tolerance in rat kidney transplantation.METHODS：①Forty Wistar rats,half males and half females,were randomly assigned into the control group（n=20） and experimental group（n=20）.The female animals were injected bone marrow cell and normal salty in portal vein.After 30 days,the chimerism formation and rejection were observed by gross and under a light microscope.②Living-related kidney transplantation comprised 5 pairs of living kidney transplantations（couples or relatives）.Males served as donors and females were recipients.Tacrolimus was taken orally before operation.The donors were subcutaneous injected drugs to stimulate leukocyte growth.The leukocyte suspension liquid was collected,determined by flow cytometry and infused into recipients via peripheral vein.The procedure was repeated once after 10 days,and the transplantation was performed within 1 week.The renal function was examined after operation.Y gene fragment was determined after half years by fluorescence in situ hybridization.The control group received normal living-related kidney transplantation without bone marrow cells transplantation.RESULTS AND CONCLUSION：The rejection was slightly in the animal experimental group,with positive chimerism.Four cases showed chimerism-positive in the living transplantation group,but only 1 chimerism-positive in the control group.It is suggested that bone marrow cell injection can induce immunological tolerance,which relates to the chimerism formation of donor bone marrow cells injection before the transplantation.