A team under the direction of Stanford bioengineer Steve Quake, PhD, has shown that a noninvasive blood test can accurately diagnose lung-transplant rejection. The test also simultaneously detects infections by patient-imperiling microbes.
About 3,500 lung transplant procedures are performed annually worldwide. But median survival after the graft barely exceeds five years, trailing the outcomes for kidney, heart, liver and other solid organ transplants. Chronic organ rejection is the biggest single factor. Infection (for which recipients are at high risk due, ironically, to their post-transplant regimen of immune-suppressing drugs given to reduce the likelihood of organ rejection) is another leading contributor.
In a study published in Proceedings of the National Academy of Sciences, Quake and his associates demonstrated that the test, which involves high-throughput sequencing of DNA, flags organ rejection by detecting increasing amounts of donor DNA in a recipient's blood. The relatively low-cost test doesn't require the highly invasive removal of lung tissue, and it can also screen for myriad bacterial, viral and fungal pathogens.
In another study in 2014, Quake and Stanford colleagues had come up with a similar blood test to determine whether a heart-transplant recipient was headed for organ rejection. The new study expands the test's applicability to lung transplantation - and suggests that its utility may extend to solid organs in general, including more-frequently performed procedures such as kidney transplantation (more than 17,000 in the United States alone in 2014).
With better than half of all lung-transplant patients suffering organ rejection in just the first year after their operation, this advance holds great clinical potential. Quick, accurate diagnosis is the first step toward appropriate treatment.
Previously: A simple blood test may unearth the earliest signs of heart transplant rejection, Step away from the DNA? Circulating *RNA* in blood gives dynamic information about pregnancy, health and Might kidney-transplant recipients be able to toss their pills?
Photo by Lorraine Santana