Background End-stage renal disease is associated with premature ageing of the T cell immune system but inter-individual variation is substantial. The hypothesis was tested that advanced immunological T cell ageing assessed by peripheral T cell differentiation increases the long-term mortality risk after renal transplantation. Results Circulating T cells of 211 recipients of a kidney from a living donor were analyzed before and in the first year after transplantation. The number of CD31-positive naive T cells (as a marker for recent thymic emigrants) and the differentiation status of the memory T cells was assessed. Thirty recipients died during follow-up of at least 5 years. Absolute numbers of naive CD4+ (living:258 cells/μl vs. deceased:101 cells/μl, p < 0.001) and naive CD8+ T cells (living:97 cells/μl vs. deceased:37 cells/μl, p < 0.001) were significantly lower in the deceased group prior to transplantation. In a multivariate proportional hazard analysis the number of naive CD4+ T cells remained associated with all-cause mortality (HR 0.98, CI 0.98-0.99, p < 0.001). The low number of naive T cells in the deceased patient group was primarily caused by a decrease in recent thymic emigrants (i.e. less CD31+ naive T cells) indicating a lowered thymus function. In addition, the physiological age-related compensatory increase in CD31- naïve T cells was not observed. Within the first year after transplantation, the number and characteristics of naive T cells remained stable. Conclusions A severe reduction in circulating naïve T cells because of a decrease in recent thymic emigrants is highly associated with all-cause mortality after renal transplantation.

中文翻译：

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非常低的胸腺功能表明肾移植后长期死亡风险显着增加的患者。

背景 终末期肾病与 T 细胞免疫系统的过早老化有关，但个体间差异很大。假设通过外周 T 细胞分化评估的晚期免疫 T 细胞老化增加了肾移植后的长期死亡风险。结果 对来自活体供体的 211 名受者的循环 T 细胞进行了分析，并在移植前和移植后的第一年进行了分析。评估了 CD31 阳性幼稚 T 细胞的数量（作为近期胸腺迁移的标志物）和记忆 T 细胞的分化状态。30 名受者在至少 5 年的随访期间死亡。幼稚 CD4+（活：258 细胞/μl 与死者：101 细胞/μl，p < 0.001）和幼稚 CD8+ T 细胞（活：97 细胞/μl 与死者：37 细胞/μl，p < 0. 001）在移植前死亡组显着降低。在多变量比例风险分析中，幼稚 CD4+ T 细胞的数量仍然与全因死亡率相关（HR 0.98，CI 0.98-0.99，p < 0.001）。已故患者组中幼稚 T 细胞数量少的主要原因是近期胸腺迁移减少（即 CD31+ 幼稚 T 细胞减少），表明胸腺功能降低。此外，未观察到 CD31-naive T 细胞与生理年龄相关的代偿性增加。在移植后的第一年内，幼稚T细胞的数量和特征保持稳定。结论由于近期胸腺移出者的减少导致循环初始 T 细胞的严重减少与肾移植后的全因死亡率高度相关。