http://www.digitaljournal.com/article/358146

New kidney transplant safety test

Posted Sep 11, 2013 by Tim Sandle
A simple test that can reveal whether a kidney transplant recipient is at imminent risk of organ rejection has been developed. The test checks urine levels of an immune protein.
Kidneys exposed
Kidneys are exposed in the sketch.
Jay David Murphy
Essentially the test works by looking for increases in urine levels of an immune protein called CXCL9, according to Global Times. It has been found that the protein often shows up in patients a month before an episode of organ rejection, thereby acting as an ‘early warning’.
The test is designed to lessen the need for kidney biopsies in some patients and pinpoint others who might safely reduce their dose of immune-suppressing drugs. Transplant recipients are often administered drugs to suppress their immune systems, but such medicines leave the patient susceptible to infection and some, such as steroids, can cause serious side effects. With further testing the urine test might identify patients who have low CXCL9 levels and thus might require less immune suppression since they would have a lower rejection risk.
A kidney transplant rejection is very serious. In rejection, the immune system attacks the organ, damaging tissue and posing the risk of kidney failure, meaning that the organ stops filtering blood. At present, a kidney biopsy 9the surgical removal of a small piece of tissue) is the main procedure for determining if a transplanted organ is in danger. The downside with this is that it can take a while to process the sample and to obtain a result.
The test has been reported to the American Journal of Transplantation. The paper is titled “Multicenter validation of urinary CXCL9 as a risk-stratifying biomarker for kidney transplant injury.”