Proteomic Analysis for Identification of Biomarkers that Predict Severe Acute Kidney Injury

The search for acute kidney injury (AKI) biomarkers has identified a number of urine proteins that can be used to predict the presence of AKI but has struggled to identify proteins that are prognostic for severe AKI. In this review, we discuss 2 currently available biomarkers and the designs of the studies in which they were identified and relate this to the AKI characteristics they predict clinically. We discuss recent advances in mass spectrometry and sample preparation, which have improved the ability to identify low abundance proteins as well as the ability to characterize more of the protein by mass spectrometry. We show how these changes can lead to a deeper and more thorough analysis of the urine proteome. Finally, we highlight 2 important issues that can help in the identification of these biomarkers, appropriate study design and adequate technical characteristics in the analysis.