A simple but potentially life saving test has been developed by Otago University researchers to detect a common cause of kidney transplant failure. The urine test detects levels of a molecule, major histocompatibility complex (MHC), which soar during transplant rejection. Four out of every 120 New Zealanders lose their kidney transplant within the first year, says Dr Alex McLellan of the University’s Department of Microbiology and Immunology. “Detecting transplant rejection at the earliest possible time is essential to prevent transplant loss because it allows immediate intervention with additional immunosuppressive drugs.” Dr McLellan hopes the test, which is the result of a seven year study of New Zealand, Australian and Swiss kidney transplant patients, will eventually replace the current invasive biopsy procedure. “The kidney biopsy is still the most reliable method to date for diagnosing transplant rejection but is invasive. The urine test is rapid, simple and non-invasive, requiring basic materials to detect a molecule released into urine during transplant rejection,” Dr McLellan says. While unlikely to be available for some years until further testing on larger groups of  kidney transplant patients has been done, the researchers believe it will improve diagnostic monitoring during the post-transplant hospitalisation of patients and potentially be used by patients at home for long-term monitoring of transplant status.