Levels of a protein in the urine of kidney transplant recipients can distinguish those at low risk of developing kidney injury from those at high risk, a study suggests. The results also suggest that low levels of this protein, called CXCL9, can rule out rejection as a cause of kidney injury. The study was published online on August 22, 2013 in the American Journal of Transplantation. The work was funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. To prevent rejection, kidney transplant recipients typically take immunosuppressive drugs every day. However, these drugs can cause kidney damage and lead to other serious side effects such as cancer, infection, and infertility. Even with immunosuppressive therapy, 10 to 15 percent of kidney recipients experience rejection during the first year after transplantation. Currently, the only definitive way to distinguish rejection from other causes of kidney injury is by performing a biopsy, in which doctors remove a small piece of kidney tissue to look for rejection-associated damage. Although this procedure is generally considered safe, it carries some minor risks for the patient and does not always provide an accurate impression of the overall state of the kidney. "A noninvasive urine test to accurately monitor the risk of kidney rejection could dramatically reduce the need for biopsies and possibly enable doctors to safely reduce immunosuppressive therapy in some patients," said NIAID Director Anthony S. Fauci, M.D.Login Or Register To Read Full Story