Clinical proteomics--on the long way from bench to bedside?

The increasing number of patients suffering from chronic renal failure represents one of the major challenges which the nephrologists are facing worldwide. For a better therapeutic outcome of this disease, earlier detection is urgently warranted in routine clinical practice. The standard approaches in diagnosing renal diseases remain severely limited. New techniques, such as analysis of the diseased renal proteome, are highly promising [1–6]. Beside direct analysis of renal tissue, mass spectrometric approaches to urinary peptide/protein profiling promise potential value in the non-invasive diagnosis, monitoring or prediction of renal and urinary tract diseases. First examples of such progress have been reported in a recent paper of Decramer et al. [1], who report that urinary proteomic analysis can predict the need for operation in newborns presenting with unilateral uretero-pelvic junction obstruction with high significance. Furthermore, certain publications imply the possibility of an early detection of graft rejection by urinary proteomics [5,7]. Several investigators also report on specific new biomarker candidates for other renal disease detected by proteomic analysis [8–11]. What is proteomics?