DNA Test Detects Heart Rejection

Smidt Heart Institute researchers are investigating a DNA-based blood test they believe can detect acute cellular rejection soon after heart transplants, improving patients' chance of survival and eliminating the need for multiple invasive biopsies.

Jon Kobashigawa, MD

The test measures circulating donor DNA in a transplant recipient's blood. An abnormally high level of donor DNA would indicate the recipient's immune system is beginning to attach the new heart. The test could allow researchers to detect rejection early and intervene if necessary.

"About 20 to 30 percent of heart transplant patients have some form of rejection in the first year post-transplant," said Jon Kobashigawa, MD, director of the Heart Transplant Program and principal investigator for the study. He's collaborating with CareDX, Inc., develop of the cell-free DNA test.

"Depending on severity, the recipient's quality of life can be difficult in terms of recurrent heart failure symptoms," he said.

Routine endomyocardial biopsies remain the standard criterion for monitoring allograft health and rejection, a process that involves taking a tissue sample of the right ventricle and having a pathologist evaluate it. Biopsies help clinicians tailor the use of an immunosuppressant to prevent rejection.

Preliminary results indicate the DNA test can detect rejection at an early stage. Kobashigawa presented his preliminary findings during a plenary session at the American Transplant Congress meeting in May 2015.

Smidt Heart Institute continues to lead the field in adult heart transplants with 120 in 2014. The mark set a new national standard for most adult heart transplants in a single year.

Kobashigawa hopes to enroll more heart transplant patients into the study to expand his findings. The study is open to most patients who have not demonstrated heart rejection in the first two months following their heart transplant.