Early Validation of Urinary Biomarkers of Renal Obstruction

描述（由申请人提供）：肾梗阻或肾盂输尿管交界处梗阻（UPJO）可导致肾功能丧失和肾异常成熟。适当的早期手术干预可预防肾损害。临床困境是确定哪些儿童需要干预以及何时干预。肾梗阻常导致肾积水或肾扩张；然而，肾积水并不一定意味着临床上明显的梗阻。更复杂的是，高达5%的孕妇被诊断为产前肾积水，其中30%可能是由UPJO引起的。这大大增加了出生后可能需要筛查的儿童人数。目前的诊断仅限于侵入性的成像方式，使儿童暴露于电离辐射，可能需要全身麻醉，并且受其主观性质的限制。尽管存在良好的手术治疗，但(1)没有明确的临床试验来确定哪些肾积水患者需要手术；(2)没有建立产后诊断检测或干预的临床指南；(3)没有能力确定谁有未来长期肾损害的风险。迫切需要一种更准确的非侵入性检测来规范临床指南、诊断和管理。使用我们实验室开发的基于质谱（MS）的方法；我们从一项无偏倚的尿蛋白组定量发现研究中鉴定的1114种蛋白质中确定了76种潜在的UPJO尿液生物标志物候选列表。有趣的是，有一种特殊的蛋白质亚群（24）与氧化应激有关，在尿液中有显著的数量差异。此外，来自另一个队列的数据确定了尿基质金属蛋白酶（MMP）作为UPJO临床生物标志物的潜在作用。我们的数据表明，有特定的尿液生物标志物有潜力确定哪些肾积水儿童需要手术干预UPJO。在本提案中，我们提出了候选尿液标志物作为UPJO诊断工具的第一个严格的早期验证试验。我们假设UPJO患儿的尿蛋白质组包含临床上有用的肾梗阻生物标志物，这些标志物将非侵入性地决定哪些儿童应该接受手术干预，而不是观察。我们将以以下具体目标挑战这一假设：1)使用定向质谱和MMP分析确定UPJO患者膀胱无创尿液中的“最佳”标记组。2)确定UPJO标记的“最佳”组是否允许在纵向混合性疾病队列中对肾积水患者进行分层。这些研究专门用于预先验证尿液生物标志物，这些生物标志物有可能显著改变和改善大量儿童肾积水的临床管理。这些高度转化实验的发现可能是前瞻性临床试验的基础。

DESCRIPTION (provided by applicant): Renal obstruction, or ureteropelvic junction obstruction (UPJO), can result in loss of kidney function and abnormal renal maturation. Appropriate early surgical intervention may prevent renal damage. The clinical dilemma is identifying which children need intervention and when. Renal obstruction always results in hydronephrosis, or dilation of the kidney; however, hydronephrosis does not always indicate clinically significant obstruction. To further compound the quandary, up to 5% of all pregnancies have a diagnosis of prenatal hydronephrosis, in which 30% may be caused by UPJO. This considerably increases the number of children who may need screening after birth. Current diagnostics are constrained to imaging modalities that are invasive, expose the children to ionizing radiation, may require general anesthesia, and are limited by their subjective nature. Although excellent surgical treatment exists, there are (1) NO definitive clinical tests that determine who with hydronephrosis requires surgery; (2) NO established clinical guidelines for postnatal diagnostic testing or intervention; and (3) NO ability to determine who is at risk for future long-term renal damage. A more accurate non-invasive test to standardize clinical guidelines, diagnosis, and management is sorely needed. Using a mass spectrometry (MS) based method developed in our laboratory; we identified a candidate list of 76 potential urinary biomarkers of UPJO from over 1114 proteins identified in an unbiased quantitative discovery study of the obstructed urinary proteome. Interestingly, there was a particular subset of proteins (24) involved with oxidative stress that had dramatic quantitative fold differences in the urine. I addition, data generated from an additional cohort identified a potential role of urinary matrix metalloproteinases (MMP) as a clinical biomarker for UPJO. Our data suggests that there are specific urinary biomarkers that have the potential to determine which children with hydronephrosis require surgical intervention for UPJO. In this proposal we present the first rigorous early-validation trial of candidate urinary markers as diagnostic tools for UPJO. We hypothesize that the urinary proteome of children with UPJO contains clinically useful biomarkers of renal obstruction that will non-invasively determine which children should undergo surgical intervention versus observation. We will challenge this hypothesis with the following specific aims: 1) Identify the "best" panel of markers in noninvasively obtained urine from the bladder of UPJO patients using directed MS and MMP profiling. 2) Determine if the "best" panel of UPJO markers allows for stratification of patients with hydronephrosis in a longitudinal mixed disease cohort. These studies are specifically designed to pre-validate urinary biomarkers that have the potential to significantly alter and improve the clinical management of a very large population of children with hydronephrosis. The findings of these highly translational experiments may be the basis for a prospective clinical trial.