Researchers have developed a simple blood test that can detect when a newly transplanted lung is being rejected by a patient, even when no outward signs of the rejection are evident. The test could make it possible for doctors to intervene faster to prevent or slow down so-called chronic rejection—which is severe, irreversible, and often deadly—in those first critical months after lung transplantation. Researchers believe this same test might also be useful for monitoring rejection in other types of organ transplants.
Called the donor-derived cell-free DNA test, the experimental test begins with obtaining a few blood droplets taken from the arm of the transplant recipient. A special set of machines then sorts the DNA fragments in the blood sample, and in combination with computer analysis, determines whether the fragments are from the recipient or the donor and how many of each type are present. Because injured or dying cells from the donor release lots of donor DNA fragments into the bloodstream compared to normal donor cells, higher amounts of donor DNA indicate a higher risk for transplant rejection in the recipient.
“This test solves a long-standing problem in lung transplants: detection of hidden signs of rejection,” said Hannah Valantine, M.D., co-leader of the study and lead investigator of the Laboratory of Organ Transplant Genomics in the Cardiovascular Branch at NHLBI. “We’re very excited about its potential to save lives, especially in the wake of a critical shortage of donor organs.”
“Earlier detection could allow earlier intervention,” added Sean Agbor-Enoh, M.D., Ph.D., study co-author and co-director of NHLBI’s Laboratory of Organ Transplant Genomics. “Once rejection is detected early via this test, doctors would then have the option to increase the dosages of anti-rejection drugs, add new agents that reduce tissue inflammation, or take other measures to prevent or slow the progression.”
The study, partly funded by NHLBI, appeared in EBioMedicine, a publication of The Lancet.