两种不同免疫抑制方案对肾移植受者免疫状态的影响

摘要

Objective To assess the impacts of sirolimus(SRL)and tacrolimus(TAC)on immune condition in renal transplant recipients,in order to find the optimal immunosuppressive regimens. Methods According to the different immunosuppressive regimens,18 living donor renal transplant recipients with stable renal function were divided into two groups:SRL group(n=8)on SRL + mycophenolate mofetil(MMF)+ prednisone(Pred) and TAC group(n=10)on TAC+MMF+Pred. All the patients received the immunosuppressive regimens for at least one year. The living donors were chosen as the blank control. All the subjects of the 3 groups were examined for the proportion of Regulatory T(Treg)cells(CD4+CD25+Foxp3+)and Regulatory B(Breg)cells(CD19+CD5+CD1d+) in their peripheral blood mononuclear cells(PBMCs)by flow cytometry. After stimulation by the corresponding donor's PBMCs,the recipient's PBMCs were measured through the production of interferon-γ(IFN-γ)and interleukin-10(IL-10)of the recipient's PBMCs of SRL group and TAC group were measured by enzyme-linked immunospot assay(ELISPOT). Results The proportion of CD4+ CD25+ Foxp3+ Treg in the SRL group,TAC group and blank control group were(6.68±0.42)%,(3.59±0.47)%and(6.59±0.36)%,respectively. The ratio of the SRL group and blank control group were significantly higher than that of the TAC group(both P0.05). The proportion of CD19+CD5+CD1d+B cells in the SRL group,TAC group and blank control group were(16.43±3.56)%, (13.09±1.64)%and(16.58±1.31)%,respectively. There were no statistically significant differences among the three groups(all P>0.05). The frequency of the cellsproducing IFN-γin the SRL group and TAC group detected by ELISPOT were(117.00±21.54)/ 500 000 and(126.00±24.08)/ 500 000, without significant difference (P>0.05). The frequency of the cellsproducing IL-10 in the SRL group and TAC group were(347.00±55.29)/500 000 and(249.00±58.97)/ 500 000,without significant difference(P>0.05). Conclusion The regimen based on SRL shows no effect on the percentage of Treg of PBMC in long-term renal transplant recipients,however, the regimen based on TAC reduces the percentages. Meanwhile,both the regimens have no impact on the proportion of Breg in the peripheral CD19+B cells and on the donor-specific immune reaction.%目的通过比较两种不同免疫抑制方案对肾移植术后受者免疫状态的影响，以寻找有利于移植物长期存活的免疫抑制方案。方法研究纳入亲属活体肾移植受者18例，肾功能稳定。根据应用免疫抑制方案的不同分为两组：西罗莫司（SRL）组8例，方案为SRL+吗替麦考酚酯（MMF）+泼尼松（Pred）；他克莫司（TAC）组10例，方案为TAC+MMF+Pred；两组用药时间均超过1年。相应的亲属活体肾移植供者作为空白对照。采用流式细胞技术检测3组外周血调节性T细胞（Treg）（CD4+CD25+Foxp3+）、调节性B细胞（Breg）（CD19+CD5+CD1d+）占外周血淋巴细胞的比例，采用酶联斑点免疫试验（ELISPOT）检测SRL组、TAC组肾移植受者外周血淋巴细胞经其相应供者外周血淋巴细胞特异刺激后，分泌特异性细胞因子γ-干扰素（IFN-γ）、白细胞介素-10（IL-10）的单个细胞频数。结果 SRL组肾移植受者外周血CD4+CD25+Foxp3+ Treg占总CD4+T细胞的比例为（6.68±0.42）％，TAC组为（3.59±0.47）％，空白对照组为（6.59±0.36）％，SRL组和空白对照组显著高于TAC组（均P＜0.05），SRL组与空白对照组比较差异无统计学意义（P＞0.05）。SRL组外周血Breg（CD19+CD5+CD1d+）占CD19+ B细胞的比例为（16.43±3.56）％，TAC组为（13.09±1.64）％，空白对照组为（16.58±1.31）％，3组之间两两比较差异均无统计学意义（均P＞0.05）。ELISPOT检测SRL组分泌IFN-γ的细胞频数为（117.00±21.54）/500000， TAC组为（126.00±24.08）/500000；分泌IL-10的细胞频数SRL组为（347.00±55.29）/500000，TAC组为（249.00±58.97）/500000，两组比较差异均无统计学意义（均P＞0.05）。结论长期应用以SRL为基础的免疫抑制方案并不影响Treg占外周血淋巴细胞的比例，而应用以TAC为基础的免疫抑制方案会降低外周血Treg的数量；两种方案都不影响Breg占外周血CD19+B细胞的比例，而且也不影响受者对供者的特异性反应性。