Divisions of Biotechnology Core, Department of Pediatrics, Stanford University School of Medicine, Stanford University, Stanford, California, USA.
J Am Soc Nephrol. 2010 Apr;21(4):646-53. doi: 10.1681/ASN.2009080876. Epub 2010 Feb 11.
Noninvasive methods to diagnose rejection of renal allografts are unavailable. Mass spectrometry followed by multiple-reaction monitoring provides a unique approach to identify disease-specific urine peptide biomarkers. Here, we performed urine peptidomic analysis of 70 unique samples from 50 renal transplant patients and 20 controls (n = 20), identifying a specific panel of 40 peptides for acute rejection (AR). Peptide sequencing revealed suggestive mechanisms of graft injury with roles for proteolytic degradation of uromodulin (UMOD) and several collagens, including COL1A2 and COL3A1. The 40-peptide panel discriminated AR in training (n = 46) and test (n = 24) sets (area under ROC curve >0.96). Integrative analysis of transcriptional signals from paired renal transplant biopsies, matched with the urine samples, revealed coordinated transcriptional changes for the corresponding genes in addition to dysregulation of extracellular matrix proteins in AR (MMP-7, SERPING1, and TIMP1). Quantitative PCR on an independent set of 34 transplant biopsies with and without AR validated coordinated changes in expression for the corresponding genes in rejection tissue. A six-gene biomarker panel (COL1A2, COL3A1, UMOD, MMP-7, SERPING1, TIMP1) classified AR with high specificity and sensitivity (area under ROC curve = 0.98). These data suggest that changes in collagen remodeling characterize AR and that detection of the corresponding proteolytic degradation products in urine provides a noninvasive diagnostic approach.
目前尚无诊断肾移植排斥反应的非侵入性方法。质谱分析结合多重反应监测为鉴定疾病特异性尿肽生物标志物提供了一种独特的方法。在这里，我们对 50 名肾移植患者和 20 名对照者（n=20）的 70 个独特样本进行了尿肽组学分析，鉴定出 40 个用于急性排斥反应（AR）的特定肽段。肽序列分析揭示了与尿调蛋白（UMOD）和几种胶原蛋白（包括 COL1A2 和 COL3A1）的蛋白水解降解有关的移植物损伤的提示性机制。该 40 肽面板可区分训练集（n=46）和测试集（n=24）中的 AR（ROC 曲线下面积>0.96）。对配对肾移植活检的转录信号进行综合分析，与尿液样本相匹配，除了 AR 中外细胞基质蛋白的失调（MMP-7、SERPING1 和 TIMP1）外，还揭示了相应基因的协调转录变化。在 34 例具有和不具有 AR 的独立移植活检样本上进行定量 PCR 验证了排斥组织中相应基因表达的协调变化。一个由 6 个基因组成的生物标志物面板（COL1A2、COL3A1、UMOD、MMP-7、SERPING1、TIMP1）可高度特异性和敏感性地分类 AR（ROC 曲线下面积=0.98）。这些数据表明，胶原重塑的变化特征是 AR，并且在尿液中检测到相应的蛋白水解降解产物提供了一种非侵入性的诊断方法。
