Proteomics and renal transplantation: searching for novel biomarkers and therapeutic targets.

Renal transplantation has emerged as the preferred option for many patients with endstage renal failure. While significant progress has been achieved in short-term outcomes, long-term survival has only marginally improved. Adaptation of immunosuppressive drugs to the individual needs of every patient at every time point after transplant will be essential to improve long-term outcomes. Thus, assays are required that detect allograft injury very early, which implies frequent noninvasive measurements (e.g. in urine or serum). In this review, we describe important general aspects in urine biomarker discovery using proteomics and discuss currently published studies. Although proteomics has the potential to provide insights into complex pathophysiological processes and reveal novel diagnostic biomarkers as well as therapeutic drug targets, the actual status of urine proteomic activities in renal transplantation is still far from reaching these ambitious goals.