术前受者外周血中抗原特异性单个效应细胞频数对急性排斥反应的影响

Pretransplant frequency of donor-specific, IFN-γ-producing lymphocyte correlates with the risk of (post)-(transplant) rejection episodes

目的探讨术前受者外周血抗原特异性单个效应细胞频数与肾移植后急性排斥反应的关系。方法采用酶联免疫斑点实验方法,检测8名健康志愿者及25例肾移植受者术前外周血淋巴细胞经同种异体抗原刺激后分泌特异性细胞因子(γ干扰素、白细胞介素2、白细胞介素4和白细胞介素5)的单个效应细胞频数,并对25例受者肾移植后的情况进行随访,时间至少为半年。结果8名健康志愿者外周血中分泌γ干扰素(INFγ)的细胞的频数最高,为15/500000～120/500000,其频数在连续4个月内相对稳定。受者术前体内存在的供者特异性的、分泌INFγ的细胞频数与供、受者间HLA配合情况无关;25例肾移植受者中,21例移植术后均未发生急性排斥反应,其术前供者特异性的、分泌INFγ的细胞频数除2例外,均低于40/500000;4例术后发生急性排斥反应,术前供者特异性的、分泌INFγ的细胞频数分别为86/500000、104/500000、128/500000及264/500000。结论移植术前测定受者体内供者特异性的、分泌INFγ的细胞频数可以作为评估受者针对供者的特异性免疫反应能力的方法之一,并为术后急性排斥反应的防治提供参考。

Objective To analyze the relationship between the pretransplant frequency of donor-specific INF-γ memory PBLs and the posttranplant risk of developing acute rejection episodes.Methods Blood samples were obtained from patients (n=25) evaluated for renal transplantation at our transplant center and normal healthy volunteers (n=8). The frequencies of responding memory T cells producing donor-specific cytokines (INF-γ, IL-2, IL-4, IL-5) at single cell resolution of volunteers and patients were measured by ELISPOT assay. Twenty-five patients subjected to cadaveric renal transplantation were followed up for at least 6 months.Results The frequency and cytokine profile of all reactive PBLs from 8 normal healthy volunteers revealed a dominance of IFN-γ (range of 15-120 spots/500 000 PBLs) over the other cytokines in each case tested. Moreover, the frequency of allo-induced IFN-γ spots varied minimally when responders from 3 volunteers were retested serially with the same stimulator within 4-month time span. The results from this study showed that the pretransplant frequency of donor-specific IFN-γ-producing cells may not be predictable based on the number of HLA mismatches alone. Among 25 recipients, 21 recipients except 2 have not had a rejection episode in which the donor-specific IFN-γ-producing cells were less than 40/500 000 PBLs, while the other 4 (recipients) developed acute rejection in which the frequency of donor-specific responses were 86, 104, 128, 264/500 000 PBLs, respectively.Conclusion This assay of detecting the pretransplant frequency of donor-specific IFN-γ-producing cells may be one of the useful immunologic tools for evaluating the strength of pretransplant alloreactivity. It can provide information useful in predicting the risk of acute rejection following renal transplantation.