New Technique Preserves Donor Lungs, Reduces Organ Rejection

Ex-vivo lung perfusion keeps the lung alive, breathing outside the body and supported by a supply of blood and nutrients.

Ex-vivo lung perfusion keeps the lung alive, breathing outside the body and supported by a supply of blood and nutrients.

Researchers at the University of Manchester have begun using a new technique that transforms poorly functioning lungs into optimal organs for transplant and reduces the risk of organ transplant rejection.

Lung transplantation is often the only option left for patients with end stage lung disease, but this option is limited due to the shortage of donor organs. If a patient is lucky enough to receive a donor organ, they must continue on immunosuppression medications for the duration of their lives to prevent the organ from being rejected by their immune system. This process is often triggered by the presence of the donor lung’s white blood cells that migrate into the recipient’s body and are viewed as harmful.

The technique, used by the researchers in collaboration with the University of Lund in Sweden, is called ex-vivo lung perfusion (EVLP), wherein the lung is kept alive, breathing outside the body and supported by a supply of blood and nutrients.

This process can repair organs that were originally turned down for transplant. As 80% of donor organs are labeled as unusable, the technique is expected to significantly shorten the waiting list times and increase access to transplantation.

“Because the lung is a potential entry route for infection into the body, its immune response is highly developed,” said Dr. James Fildes, from the University’s Collaborative Centre for Inflammation Research and the Transplant Centre at the University Hospital of South Manchester NHS Foundation Trust and lead researched on the study. “In lung transplantation, the situation is made worse by the processes that occur in the donor, which automatically increase the activity of the immune system.

“All of this makes lung transplant recipients particularly susceptible to rejection, so they require continuous immunosuppression, which then increases the risk of infection and cancer. These immune processes are therefore very important and contribute to the outlook where only 5 out of 10 patients will survive for at least 5 years.”

The research teams from both universities used lungs from pigs and transplanted them using either traditional methods or after 3 hours of EVLP. The recipients were monitored for 24 hours. The results were that the EVLP lungs took to the recipients more easily, while traditional methods yielded severe signs of rejection.

EVLP is becoming an established technique, but this is the first time it has been used for this purpose. Researchers hope that by using this technique, more patients will have access to scarce donor lungs and instances of rejection will go down.

Since the lungs were only monitored for 24 hours, it is difficult to tell how the recipients will continue to respond from the EVLP lungs. However, even a delay would be beneficial in allowing the transplanted organ to become accepted. The researchers are even developing their own immunosuppression agents in the hopes of finding even more benefits.

“Aside from the benefits shown in this study, it is possible that EVLP could be used to deliver drugs before the lung is implanted so that the patient’s immune system does not recognize the transplanted organ as harmful,” added Dr. Fildes. “EVLP opens up new possibilities in one of the most problematic areas of surgery.”