Lung Transplant Rejection Reduced By New Filtering Technique

Lung Transplant Rejection Reduced By New Filtering Technique

A new technique called lung filtering may offer hope for end-stage lung disease patients in need of a lung transplant. According to researchers from the University of Manchester, which is cooperating with a team from Lund University in Sweden, filtering lungs is helping to recondition poorly functioning lungs and remove donors’ blood white cells, known as leukocytes. Using this new approach to prepare and improve lungs for transplant, the researchers expect to reduce the risk of acute rejection.

In many cases, lung transplant is the only option available for end-stage lung disease patients, but the process suffers from bottlenecks such as the shortage of organs available and intensive “after transplant” care. In fact, after transplantation, patients need lifelong immunosupression treatments in order to prevent their own immune system from destroying the transplanted organ. This naturally occurs since the patient’s new lungs in most of the cases contain leukocyte cells. Once these cells migrate into the recipient’s body, there is a conflict between the organ’s leukocytes and the recipient’s leukocytes. As a result, the patient’s immune system identifies the new organ as a threat and tries to eliminate it.

Immunosuppression therapies are used to help prevent acute and chronic rejection as well as loss of the transplanted lung. These types of therapies usually address induction, maintenance, and rejection treatment.

The novel “filtering” technique used by the Lund University research team is a new ex-vivo lung perfusion (EVLP) through which the lung is kept alive outside of a human body, supported by a supply of blood and nutrients provided artificially. By maintaining organs in these conditions, it is possible to keep them alive, for a longer period of time, therefore increasing the number of organs available for transplant.

Dr. James Fildes, from the Transplant Centre at the University Hospital of South Manchester NHS Foundation Trust, is the leader of this study and explained that “Because the lung is a potential entry route for infection into the body, its immune response is highly developed. 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 five out of ten patients will survive for at least five years.”

The two teams used transplanted pigs’ lungs either using a traditional transplant technique and lungs that had been conditioned using EVLP. All the recipient pigs were monitored for 24 hours. They realized that in the EVLP lungs, there was only a slight evidence of rejection, while in the normal transplant the lungs showed severe rejection.

Researchers now believe that EVLP is a technique that can help reduce high rates of rejection and wastage of scarce donor lungs. Even though the long term effects are still not known, it appears to be a promising technological progress since it helps donor lungs to be accepted by the body. If the approach is paired in conjunction with new immunosuppressive agents that are being developed, the researchers hope for even more improved transplant benefits.

Leave a Comment