Metabolomics: a complementary tool in renal transplantation.

Renal transplant success is closely tied to the ability to monitor transplant recipients and responsively change their medications. However, transplant monitoring still depends on relatively dated technologies - serum creatinine levels, urine output, and histopathology of biopsy samples. These techniques do not offer sufficient specificity, sensitivity, or accuracy for appropriate and timely interventions. As a result, more specific diagnostic techniques, based on proteomics, genomics and metabolomics are being sought. Metabolomics (the high-throughput measurement and analysis of metabolites) may make it possible to monitor transplants more effectively and specifically. Changes in the concentration profiles of a number of small molecule metabolites found in either blood or urine can be used to localize kidney damage, assess organs at risk of rejection, assess kidneys suffering from ischemiareperfusion injury or identify organs that have been damaged by immunosuppressive drugs. The application of metabolomics to kidney transplant monitoring is still in its early stages. Nevertheless, there are a number of easily measured metabolites in both urine and serum that can provide reliable indications of kidney function, kidney injury, and immunosuppressive drug toxicity. Metabolomics could serve as a good complement to existing proteomic and genomic technologies.