Urine Proteomics and Biomarkers in Renal Disease

The application of urine proteomics is a useful approach to the study of the proteins involved in healthy and diseased kidneys and may provide a noninvasive approach to assess disease activity and to monitor clinical response in patients with renal diseases. This technique may provide an additional tool in clinical trials and for the assessment of prognosis for patients. Both soluble proteins and membrane-bound (exosomal) proteins may be studied, and multiple approaches are available. Discovery proteomics is an unbiased approach to detect novel proteins in urine samples. Mass spectrometry (MS) is often needed to identify specific protein fragments. Targeted proteomics often involves specific immunoassays or modified MS, which enables a hypothesis-based design. These approaches may be integrated. For example, specific proteins may be identified by the discovery approach or laboratory study of disease mechanisms. These proteins will then be studied further by targeted proteomics. In order to translate to clinical practice, the specific assays need vigorous validation by means of sufficiently statistically powered clinical trials.