Urine Test May Improve Monitoring of Kidney Transplants
The presence of this specific mRNA is one of the first signs that rejection is beginning. So the new tests also could be used to monitor a transplant patient to see whether the immune-suppressing drugs are working right.
"Patients who develop rejection [to their transplants] develop these markers first," says Suthanthiran, chief of transplantation medicine at New York's Weill Cornell Medical Center. "Now we give drugs and say that a patient is immune suppressed -- but we don't really have a good handle on how to measure immune suppression. With this test it may be possible to look and see whether these genes are [present] or not and get a good feel for how much immune suppression a person really is getting."
Christian P. Larsen, MD, PhD, is director of the Emory University transplant center in Atlanta. He did not participate in Suthanthiran's study, but is very familiar with his work.
"I think this test will begin to be incorporated into clinical practice in the near future," Larsen tells WebMD. "It has tremendous potential. It also has the potential to change the way a given patient is managed [by their doctor]. ... [We] may be able to tailor a patient's therapy based on the results [of the urine test]."
But others are not so sure that this sophisticated technique will find wide use. Marcia Wheeler, MS, is a research associate in the urology section of the Yale University Medical School, in New Haven, Conn. She says that mRNA measurement is tricky, and that not all laboratories will get results as good as those reported by Suthanthiran.
"It is difficult to isolate mRNA from urine," Wheeler says. "They say they get 95% success -- the best people get that kind of success, but not everyone. And the isolation of mRNA is really difficult if the urine is infected, and that often is the case in people with kidney rejection."