Singapore: Researchers at Boston Children's Hospital have found a combination of biomarkers related to blood vessel and tissue injury that, when measured together, could signal when a transplanted heart is becoming damaged to the point of failure, a process that is often undetected. The markers would give doctors an opportunity to intervene and save a recipient's heart, and also provide a starting point for identifying long-term rejection biomarkers for several kinds of organ transplants.

The research team is led by Dr Kevin P Daly, and Dr David M Briscoe, of the Transplant Research Program (TRP) at Boston Children's Hospital, and Dr S Ananth Karumanchi of Beth Israel Deaconess Medical Center.

The study reflects a shift in the field of organ transplantation from short- to long-term rejection concerns, and from invasive to noninvasive methods for detecting chronic rejection early. In the 45 years since the first successful human heart transplant, concerns about short-term or acute organ rejection have largely been addressed by drugs like cyclosporine. However, long-term or chronic rejection, characterized by the loss of function in a transplanted organ over time, is becoming a larger issue, especially since transplant recipients are living longer now than ever before.

"All transplant patients eventually progress to chronic rejection," according to Briscoe, director of the TRP and a nephrologist with a long-standing interest in molecular monitoring for transplant rejection. "It's a slow process that evolves over years."

Cardiac allograft vasculopathy (CAV) is one of the main forms of chronic rejection in heart transplant patients. CAV results from continual injury to the transplanted organ's blood vessels by the recipient's immune system over time.