Urinary Polypeptide Biomarkers of IgA Nephropathy

IgA 肾病的尿多肽生物标志物

• 批准号: 7386943
• 负责人: JAN NOVAK
• 金额: $ 21.95万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7386943
• 关键词: Alabama; Amino Acid Sequence; Antigen-Antibody Complex; Biochemical Markers; Biological Assay; Biological Markers; Biopsy; Biopsy Specimen; Blood Circulation; Capillary Electrophoresis; Classification; Clinical; Clinical Data; Complement Membrane Attack Complex; Complex; Computer software; Data; Deposition; Diagnosis; Diagnostic; Diagnostic tests; Disease; Disease Progression; End stage renal failure; Enzyme-Linked Immunosorbent Assay; Evaluation; Fourier transform ion cyclotron resonance; Future; Glomerulonephritis; Glycopeptides; Goals; IgA1; Immune; Immunoglobulin A; Immunoglobulin G; Immunoglobulin M; Immunoglobulins; Individual; Kidney; Kidney Diseases; Laboratories; Machine Learning; Mass Spectrum Analysis; Measures; Modification; Monitor; Patients; Post-Translational Protein Processing; Principal Investigator; Procedures; Property; Proteins; Proteome; Proteomics; Protocols documentation; Sampling; Sclerosis; Severities; Software Tools; Staging; Symptoms; Testing; Universities; Urine; Western Blotting; base; cohort; complement C3 precursor; design; glycosylation; innovation; interstitial; molecular mass; noninvasive diagnosis; polypeptide; programs; quality assurance; tandem mass spectrometry; urinary

DESCRIPTION (provided by applicant): Our ultimate goal is to develop a non-invasive procedure for the diagnosis of IgA nephropathy (IgAN). The specific goal of the studies proposed in this application is to identify urinary polypeptides that can be used as biomarkers of IgAN. In preliminary studies, we have demonstrated elevated levels of IgA and IgG immunoglobulins and IgA-IgG complexes in the urine of IgAN patients using immune complex-specific ELISA. Furthermore, we have identified several potential urinary polypeptide biomarkers for IgAN by capillary electrophoresis-mass spectrometry (CE-MS) and sequenced some of these polypeptides using tandem mass spectrometry. Based on these data, we hypothesize that the urine proteome of IgAN patients contains disease-specific biomarkers. We propose to test this hypothesis by first confirming our preliminary data through analysis of archival urine samples collected during studies of IgAN from well-characterized patients and controls. We will determine the levels of immunoglobulins and immune complexes using classical and immune complex-specific ELISA protocols with quality assurance and verification by western blot analysis. These data will then be extended by analysis using CE-MS to identify positive and negative biomarkers of disease in which the software tool, MosaCluster, with support vector machines, will be used for classification of samples. This approach will define a membership, with positive values (disease-associated marker) and negative values (marker for normal). The results of ELISA and CE-MS will be compared and correlated with the clinical findings. Candidate biomarkers identified by CE-MS will be further characterized by Fourier transform-ion cyclotron resonance MS to define the amino acid sequence and post- translational modifications. Finally, candidate biomarkers will be verified using an independent cohort of patients and controls. This study is designed to identify markers that can be used to distinguish IgAN from other renal diseases as well as biomarkers of disease progression and severity. Relevance: IgAN is the most common primary glomerulonephritis worldwide. Currently, diagnosis requires an invasive renal biopsy and IgAN is frequently diagnosed at a very late stage. The identification of biomarkers that can be used as the basis of a noninvasive diagnostic test and/or used to monitor the course of the disease would be extremely beneficial.

描述（由申请人提供）：我们的最终目标是开发一种用于诊断伊加肾病（IgAN）的非侵入性程序。本申请中提出的研究的具体目标是鉴定可用作IgAN的生物标志物的尿多肽。在初步研究中，我们已经证明了伊加和IgG免疫球蛋白和IgA-IgG复合物的IgAN患者的尿液中使用免疫复合物特异性ELISA的水平升高。此外，我们还通过毛细管电泳-质谱（CE-MS）鉴定了IgAN的几种潜在尿多肽生物标志物，并使用串联质谱对其中一些多肽进行了测序。基于这些数据，我们假设IgAN患者的尿液蛋白质组包含疾病特异性生物标志物。我们建议首先通过分析IgAN研究期间收集的来自特征良好的患者和对照组的存档尿样来证实我们的初步数据，以检验这一假设。我们将使用经典和免疫复合物特异性ELISA方案测定免疫球蛋白和免疫复合物的水平，并通过蛋白质印迹分析进行质量保证和验证。然后，这些数据将通过使用CE-MS进行分析来扩展，以识别疾病的阳性和阴性生物标志物，其中软件工具MosaCluster与支持向量机将用于样本分类。该方法将定义成员资格，具有正值（疾病相关标志物）和负值（正常标志物）。将ELISA和CE-MS的结果进行比较，并与临床结果相关联。通过CE-MS鉴定的候选生物标志物将通过傅立叶变换-离子回旋共振MS进一步表征，以确定氨基酸序列和翻译后修饰。最后，将使用患者和对照的独立队列验证候选生物标志物。本研究旨在确定可用于区分IgAN与其他肾脏疾病的标志物以及疾病进展和严重程度的生物标志物。相关性：IgAN是全球最常见的原发性肾小球肾炎。目前，诊断需要侵入性肾活检，IgAN经常在非常晚期才被诊断出来。可以用作非侵入性诊断测试的基础和/或用于监测疾病进程的生物标志物的鉴定将是极其有益的。