Data_Sheet_1_Urinary CD8+HLA-DR+ T Cell Abundance Non-invasively Predicts Kidney Transplant Rejection.docx

Early detection of kidney transplant (KT) rejection remains a challenge in patient care. Non-invasive biomarkers hold high potential to detect rejection, adjust immunosuppression, and monitor KT patients. So far, no approach has fully satisfied requirements to innovate routine monitoring of KT patients. In this two-center study we analyzed a total of 380 urine samples. T cells and tubular epithelial cells were quantified in KT patients with graft deterioration using flow cytometry. Epigenetic urine cell quantification was used to confirm flow cytometric results. Moreover, a cohort of KT patients was followed up during the first year after transplantation, tracking cell subsets over time. Abundance of urinary cell counts differed in patients with and without rejection. Most strikingly, various T cell subsets were enriched in patients with T cell-mediated rejection (TCMR) compared to patients without TCMR. Among T cell subsets, CD8+HLA-DR+ T cells were most distinctive (AUC = 0.91, Spec.: 95.9%, Sens.: 76.5%). Epigenetic analysis confirmed T cell and tubular epithelial cell quantities as determined by flow cytometry. Urinary T cell abundance in new KT patients decreased during their first year after transplantation. In conclusion urinary T cells reflect intrarenal inflammation in TCMR. T cell subsets yield high potential to monitor KT patients and detect rejection. Hereby we present a promising biomarker to non-invasively diagnose TCMR.

肾移植（Kidney Transplant，以下简称KT）排斥反应的早期筛查仍是临床诊疗中的一大难题。无创生物标志物在检测排斥反应、调整免疫抑制治疗方案以及监测KT患者状态方面展现出极高应用潜力。截至目前，尚无一种方法能够完全满足KT患者常规监测方案的革新需求。本项双中心研究共分析了380份尿液样本，研究人员采用流式细胞术对移植肾功能减退的KT患者体内的T细胞及肾小管上皮细胞进行定量检测，并通过尿液细胞表观遗传定量分析验证流式细胞术的检测结果。此外，本研究对该队列中的KT患者开展了移植后第一年的随访，动态追踪其细胞亚群的变化情况。结果显示，伴排斥反应与无排斥反应的KT患者尿液细胞计数丰度存在显著差异；尤为值得注意的是，与未发生T细胞介导的排斥反应（T cell-mediated rejection，以下简称TCMR）的患者相比，发生TCMR的患者体内多种T细胞亚群呈现富集状态。在各类T细胞亚群中，CD8+HLA-DR+ T细胞的区分效能最为突出（曲线下面积AUC=0.91，特异性为95.9%，灵敏度为76.5%）。表观遗传分析结果验证了流式细胞术所测得的T细胞及肾小管上皮细胞定量结果。新发KT患者在移植后第一年的尿液T细胞丰度呈逐渐下降趋势。综上，尿液T细胞可反映TCMR患者的肾内炎症状态，T细胞亚群在KT患者的监测及排斥反应检测中具备极高应用价值。本研究提出了一种有望实现TCMR无创诊断的新型生物标志物。