Urine proteomic profiling to identify biomarkers of steroid resistance in pediatric nephrotic syndrome.

Long-term prognosis for children with nephrotic syndrome (NS) is directly related to steroid responsiveness. There are currently no diagnostic tests that accurately predict steroid responsiveness in pediatric NS. The initial prolonged course of daily, high-dose corticosteroid therapy thus serves both as a diagnostic and therapeutic maneuver. Urine proteomics is emerging as a potentially rich source of noninvasive biomarkers of drug responsiveness in NS. In this article, we discuss some of the initial studies of the urinary proteome in NS as well as ongoing and future challenges, define the normal urinary proteome and address the overwhelming abundance of urinary albumin and its impact on biomarker discovery.