Developing a simple test for organ rejection

Minnie Sarwal, MD, hopes that in a few years kidney transplant recipients will be able to forego biopsies to see if their bodies are rejecting the donated organ; instead a lab will analyze their urine samples, catching the telltale signs of rejection months earlier than a biopsy would—and at a fraction of the cost.

Minnie Sarwal, MDIf not for a $240,000 stimulus grant, Sarwal's project would have been put on hold. She had submitted the proposal last year to the NIH for funding, and it had received a high score. Yet a shortfall in the NIH budget meant that worthy projects such as hers could not be supported with federal research dollars.

Now that Sarwal has money made available to the NIH through the American Recovery and Reinvestment Act, her work is on track to be translated into a clinically applicable product by 2014. The money is allowing a postdoc and research assistant, who have worked on this for several years, to continue the studies.

Sarwal, a pediatric nephrologist at Lucile Packard Children's Hospital at Stanford, and her team are identifying the changes in the level of certain biomarkers in urine that would signal that the body is beginning to reject a new kidney. What makes this discovery important is that a transplant recipient now often doesn't find out that a kidney is being rejected until it is too late to prevent damage to the organ. This new development means that a rejection episode could be avoided with earlier intervention of anti-immune drugs. In addition, patients would no longer need invasive biopsies that can have complications.

Capitalizing on such biomarkers has only become possible in recent years as high-precision mass spectrometry—a technique that makes possible the quantification of specific molecules in a sample—has started to be used in clinical applications outside of research labs. Sarwal's work is showing how spectrometry, which can measure small changes in molecular biomarkers, can be used for recipients of heart, lung, liver and other organ transplants to detect organ rejection earlier. Thanks to the stimulus funds, doctors may soon have a powerful new tool at their disposal for doing molecular diagnostics.