Novel Urinary Proteomic Biomarkers for Acute Renal Transplant Rejection

描述(申请人提供)：我们在这项研究中的目标是发现诊断和预测儿童肾移植急性排斥反应的尿液非侵入性生物标志物。肾移植后的移植物存活率是终末期肾病儿童的首选治疗方法，急性排斥反应(AR)造成的移植物损伤对移植物存活率有负面影响，急性排斥反应的不完全恢复会导致慢性排斥反应和随后的早期移植物丢失。发现特异和敏感的生物标记物用于AR发病的诊断和治疗分层(类固醇与抗体)的预测，对于提高移植物存活率至关重要。在缺乏有效的非侵入性测试来诊断急性排斥反应的情况下，有创移植活检是唯一的金标准，AR的严重程度和治疗反应很难预测。由于上述原因，临床上迫切需要找到一种更具特异性的AR诊断和预测工具，它最终可能取代常规的活检。基因组学和蛋白质组学等高通量技术的进展被认为是理解复杂的双分子过程和发现生物标志物的重要一步。尿液代表血浆的滤液，因此，由于采集过程的非侵入性，尿液是理想的研究体液。尿液是肾移植研究中特别理想的生物流体来源，因为它既可以反映肾脏的局部过程，也可以反映血浆中的变化。我们的建议是使用已被证明能够识别数千种蛋白质和相对定量存在于血浆和尿液等生物液中的单个蛋白质的高度复杂的液质联用方法，以及识别尿肽特征的无标记LC-MALDI。尽管这些方法可能不能直接应用于临床环境，但从我们在AIM1的假设生成阶段获得的信息可以很容易地传输到更快速、更高通量的方法，如AIM2中的定量质谱仪(MS)，这是临床诊断的理想方法。这最终将对发现AR的诊断和预测AR治疗分层，从而改善患者的临床监测和移植存活至关重要。公共卫生相关性：移植肾的急性排斥反应仍然是需要有效解决的问题。在缺乏有效的非侵入性诊断手段的情况下，肾活检是监测移植肾临床进展的唯一途径。在这项研究中，我们建议利用两种最强大的蛋白质组学技术来识别急性排斥反应的非侵入性蛋白质组生物标记物。

DESCRIPTION (provided by applicant): Our goal in this study is to discovery of diagnostic and prognostic urinary non- invasive biomarkers for acute rejection in pediatric kidney transplantation. Graft survival after kidney transplantation, the treatment of choice for children with end stage kidney disease, is negatively impacted by graft injury from acute rejection (AR), and incomplete recovery of acute rejection results in chronic rejection and subsequent early graft loss. Specific and sensitive biomarker discovery for diagnosis of the onset of AR and for prediction of treatment stratification (steroids vs antibody), would be vital for improving the success rate of graft survival. In the absence of an effective, non-invasive test to diagnose acute rejection, the invasive transplant biopsy is the only gold standard, where AR severity and treatment response is difficult to predict. Because of aforementioned reasons, there is a clinical urgency to identify a more specific for a better diagnostic and predictive tool for AR, which could eventually replace the protocol biopsy. The advancement in high throughput techniques such as genomics and proteomics is considered as major step forward in understanding of complex bimolecular processes and biomarker discovery. Urine represents a filtrate of plasma, and is, therefore, an ideal body fluid of study due to the non-invasive nature of the collection process. Urine is a particularly ideal biologic fluid source of study in renal transplantation because it may be reflective of both local processes within the kidney as well as a reflection of changes within plasma. Our proposal is to use highly sophisticated liquid chromatography mass spectrometry (LCMS) methods which has already been proven to be capable of identifying thousands of proteins and relative quantification of the individual proteins present in bio fluids such as plasma and urine as well as label-free LC-MALDI, which identifies urinary peptide signatures. Although, these methods may not be directly applicable to the clinical setting, the information gained from our hypothesis generation stage in Aim 1, is easily transferred to a more rapid, higher- throughput method such as quantitative mass spectrometry (MS) in Aim2, which is ideal for clinical diagnostics. Which eventually will be vital for discovery for diagnosis and prediction of AR treatment stratification thereby improving patient clinical monitoring and transplant survival. PUBLIC HEALTH RELEVANCE: Acute rejection of transplanted kidney still remains the issue to be addressed effectively. In the absence of an effective noninvasive way of diagnosis, kidney biopsy is the only way to monitor the clinical progress the transplanted kidney. In this study, we propose to utilize two most powerful proteomic techniques to identify non-invasive proteomic biomarkers for acute rejection.