September 28, 2010

Researchers Decipher Transplant Rejections Quicker

(Ivanhoe Newswire) -- Scientists have discovered a simple and cheap blood test that can be used to stop organ rejection before it impairs transplanted heart and kidneys. This can save a countless number of desperate lives.

"In the past, we couldn't spot rejection episodes until they harmed the organ," Atul Butte, MD, PhD, who is co-senior author of the new research and an associate professor of medical informatics and of pediatrics at the Stanford University School of Medicine, in addition to director of the Center for Pediatric Bioinformatics at Lucile Packard Children's Hospital was quoted as saying. "Our goal is to develop blood tests that will keep transplanted organs functioning so that patients can avoid a second transplant."

The Stanford team found three proteins that are easily measured in and rise in the blood when acute rejection occurs. Acute rejection is when a patient's immune system attacks the transplanted organ. This is the first ever report of an immune rejection signal that is shared by two kinds of transplanted organs. The protein signals are now being validated in liver and lung transplant recipients as well.

The new blood test doesn't require an invasive, slow procedure like the previous method used to keep tabs on transplants. Currently, all organ recipients receive functional monitoring of their new body parts. Heart transplant patients get regular echocardiograms, for instance. If organ function drops, doctors cut a tiny sample from the transplanted tissue to check for rejection, and then adjust patients' immune-suppressing drugs accordingly. About 25 percent of kidney recipients and 40 percent of heart recipients experience an episode of acute rejection in the first year after transplant.

The blood test will let doctors skip directly to drug dosing before a transplant is damaged. Not only can the test treat rejection early, but also reduce doses of immune-supressing drugs for patients whose bodies are handling their transplanted organs well, which will reduce drug side effects. Butte believes that the test will be commercially available in three to five years.

Because ELISA-based diagnostics are already used in clinical settings, it won't be hard to modify the technology for transplant patients, Butte said. Stanford University has filed patent applications for the new test.

SOURCE: PLoS-Computational Biology, published online September 23, 2010