New "Liquid Biopsy" Could Help Save Lives.

• Position: HEART TRANSPLANTS

Researchers have developed a blood test that could make it possible for doctors to detect--then quickly prevent or slow down--acute heart transplant rejection, a potentially deadly condition that occurs in the early months after a patient has received a donor heart. They estimate that the test could eliminate up to 80% of invasive heart tissue biopsies currently used to detect rejection.

In a group of nearly 200 heart transplant recipients, the new blood test performed better than tissue biopsies, as it signaled problems even when no outward signs of rejection were evident. The study appears in Circulation, a publication of the American Heart Association.

"We showed in our initial assessment that this 'liquid biopsy' is highly sensitive for detecting acute rejection, finding it weeks to months before current clinical tools. This could potentially save lives in the wake of a critical shortage of donor organs," says senior study author Hannah Valantine, professor of cardiovascular medicine at Stanford University, Palo Alto, Calif.

Moreover, because African-Americans tend to have higher rates of heart transplant rejection and experience poorer transplant outcomes than other groups nationwide, the test could help reduce existing transplant-related health disparities that have persisted for decades.

The test, called the donor-derived cell-free DNA test, tracks DNA markers from the organ donor that appear in the blood of the transplant recipient. Because injured or dying cells from the donor organ release lots of donor DNA fragments into the bloodstream compared to normal cells, higher amounts of donor DNA indicate a higher risk for transplant rejection in the recipient. The biomarkers can be detected using specialized lab...