Urinary protein detection by iTRAQ® associated with renal transplant complications and its modification with therapy

BackgroundAfter renal transplant, surgical, infection complications, as well as graft rejection may occur; early detection through non-invasive markers is the key to change therapy and avoid biopsy.ObjectiveThe aim of the study is to determine urine protein profiles in patients undergoing renal transplant with complications and detect its variation when therapy is modified.Material and methodsUrine samples were collected from patients prior the transplant and various postoperative stages. Urinary protein profiles were obtained by peptide labelling using isobaric isotopes for relative quantification (iTRAQ®).ResultsA total of 22 patients were included, of whom 12 developed post-transplant complication: 2 with graft rejection (1 male and 1 female) and 10 (6 males and 4 females) in the group of post-transplant infections. Using iTRAQ® 15/345 and 28/113 proteins were identified and fulfilled the acceptance criteria, in graft rejection and post-transplant infections group, respectively.ConclusionsAlbumin was the only protein found in both groups, the remaining proteins were different. The five proteins with higher scores in graft rejection were: alpha-1-microglobulin, 5′-nucleotidase cytosolic III, retinol-binding protein 4, membrane protein palmitoylated 4, and serine carboxypeptidase, while post-transplant infections were: mitochondrial acetyl-coenzyme A synthetase, putative adenosyl homocysteinase 2, zinc finger protein GLIS1, putative protein FAM157B, and zinc finger protein 615. It remains to elucidate the involvement of each of these in patients with renal transplantation