Division of Nephrology and Hypertension, Weill Cornell Department of Medicine, New York, New York.
Department of Transplantation Medicine, New York-Presbyterian Hospital, New York, New York.
Clin J Am Soc Nephrol. 2021 Oct;16(10):1565-1577. doi: 10.2215/CJN.14010820. Epub 2021 Apr 27.
Immune monitoring of kidney allograft recipients and personalized therapeutics may help reach the aspirational goal of "one transplant for life." The invasive kidney biopsy procedure, the diagnostic tool of choice, has become safer and the biopsy classification more refined. Nevertheless, biopsy-associated complications, interobserver variability in biopsy specimen scoring, and costs continue to be significant concerns. The dynamics of the immune repertoire make frequent assessments of allograft status necessary, but repeat biopsies of the kidney are neither practical nor safe. To address the existing challenges, we developed urinary cell mRNA profiling and investigated the diagnostic, prognostic, and predictive accuracy of absolute levels of a hypothesis-based panel of mRNAs encoding immunoregulatory proteins. Enabled by our refinements of the PCR assay and by investigating mechanistic hypotheses, our single-center studies identified urinary cell mRNAs associated with T cell-mediated rejection, antibody-mediated rejection, interstitial fibrosis and tubular atrophy, and BK virus nephropathy. In the multicenter National Institutes of Health Clinical Trials in Organ Transplantation-04, we discovered and validated a urinary cell three-gene signature of T-cell CD3 chain mRNA, interferon gamma inducible protein 10 (IP-10) mRNA, and 18s ribosomal RNA that is diagnostic of subclinical acute cellular rejection and acute cellular rejection and prognostic of acute cellular rejection and graft function. The trajectory of the signature score remained flat and below the diagnostic threshold for acute cellular rejection in the patients with no rejection biopsy specimens, whereas a sharp rise was observed during the weeks before the biopsy specimen that showed acute cellular rejection. Our RNA sequencing and bioinformatics identified kidney allograft biopsy specimen gene signatures of acute rejection to be enriched in urinary cells matched to acute rejection biopsy specimens. The urinary cellular landscape was more diverse and more enriched for immune cell types compared with kidney allograft biopsy specimens. Urinary cell mRNA profile-guided clinical trials are needed to evaluate their value compared with current standard of care.
对肾移植受者进行免疫监测和实施个体化治疗，可能有助于实现“一次移植，终身受益”的理想目标。作为首选诊断工具的有创性肾活检技术已变得更加安全，且活检分类也更加精细。然而，活检相关并发症、活检标本评分的观察者间差异以及费用仍是人们关注的重点。免疫反应的多样性使得频繁评估移植物状态成为必要，但反复进行肾脏活检既不实际也不安全。为了解决这些现存的挑战，我们开发了尿细胞 mRNA 分析，并研究了基于假设的免疫调节蛋白编码 mRNA 绝对水平的 panel 对诊断、预后和预测的准确性。通过对 PCR 检测方法的改进以及对机制假说的研究，我们的单中心研究确定了与 T 细胞介导的排斥反应、抗体介导的排斥反应、间质纤维化和肾小管萎缩以及 BK 病毒肾病相关的尿细胞 mRNA。在多中心的国立卫生研究院器官移植临床试验-04 中，我们发现并验证了一个尿细胞三基因标志物，即 T 细胞 CD3 链 mRNA、干扰素诱导蛋白 10（IP-10）mRNA 和 18s 核糖体 RNA，其可用于诊断亚临床急性细胞性排斥反应和急性细胞性排斥反应，并对急性细胞性排斥反应和移植物功能具有预后价值。在未接受排斥活检的患者中，该标志物评分的轨迹保持平坦且低于急性细胞性排斥反应的诊断阈值，而在显示急性细胞性排斥反应的活检标本前数周，该评分急剧上升。我们的 RNA 测序和生物信息学研究发现，与急性排斥反应活检标本相匹配的尿细胞中富含急性排斥反应肾移植活检标本的基因标志物。与肾移植活检标本相比，尿细胞中的免疫细胞类型更多样化，且更丰富。需要进行尿细胞 mRNA 谱指导的临床试验，以评估其与当前标准护理相比的价值。
