Proteomics of transplant rejection

Although the number of patients receiving successful transplantation as a means of treatment for end-stage organ failure continues to increase, rejection, in particular chronic rejection still poses a major risk factor. Crucially, only 50% of allografted hearts and kidneys survive for 10 years. Currently, biopsy is the most common and, in some instances, the only means of diagnosing rejection: it is both invasive and costly. A blood or urine biomarker would overcome these problems and conceivably enable diagnosis of rejection far earlier than a biopsy because it could be diagnosed before clinical symptoms. Furthermore, development of a biomarker could lead to new insights into the disease process. In recent years, proteomics has provided a novel means of examining potential biomarkers. We discuss here the various proteomic platforms available, including 2-dimensional gel electrophoresis, mass spectrometry, and protein arrays, and the various studies exploring protein profiling in heart, lung, kidney, and liver transplantation.