July 19, 2024

New Approach to Prevent Organ Rejection by Infusing Immune Cells

Organ transplants are life-saving procedures, but the risk of organ rejection remains a major challenge. Researchers at the University of Pittsburgh School of Medicine have recently conducted a Phase 1 trial, demonstrating a potential new method to minimize the chance of organ rejection in transplant patients. The technique involves infusing immune cells from the donor into the recipient to prime the recipient’s immune system to accept the transplanted organ.

When someone undergoes an organ transplant, their immune system recognizes the new organ as foreign and launches an attack. To prevent organ rejection, patients are typically prescribed immunosuppressant drugs. However, these drugs leave patients susceptible to other illnesses. The researchers aimed to find a solution that would reduce the dependency on immunosuppressants while maintaining the effectiveness of the transplant.

The trial involved 15 patients scheduled to receive a partial liver transplant from a living donor. Before the surgery, blood was taken from the donors and a specific type of white blood cell called monocytes was isolated. These monocytes were then used to grow regulatory dendritic cells (DCregs), which play a crucial role in helping the immune system differentiate between harmful and harmless cells. The newly grown DCregs were then infused into the recipients one week before the transplant.

During the trial, the patients still received immunosuppressant drugs. The primary goal of the trial was to assess the feasibility and safety of the procedure, and it proved to be successful in those aspects. The researchers also examined any differences in immunologic activity that could indicate a reduced need for immunosuppressants. They found that even a year after the transplant, patients who received DCregs had lower levels of immune cells associated with rejection compared to the control group.

Angus Thomson, the senior author of the study, described the results as highly encouraging. The intervention appeared to modify the recipient’s immune response, potentially allowing for a safe reduction or removal of immunosuppression. This would be a significant development for the transplantation community, as patients would no longer be dependent on immunosuppressants indefinitely.

Further investigation revealed that the treatment works by producing exosomes, particles that facilitate communication between cells. Although the DCregs break down after a few days, they produce these exosomes during their short lifespan. The researchers believe that these exosomes condition the recipient’s immune system to recognize the donor cells as safe.

While other scientists have made progress in preventing rejection by using techniques like growing organs from a patient’s own cells or using genetically engineered pig organs, the new approach offers a relatively simple method, especially when the donor is still alive. This could be particularly useful for transplants involving kidneys or liver portions.

Overall, the results of this Phase 1 trial present a promising new avenue for minimizing organ rejection in transplant patients. Further research and clinical trials will be necessary to determine the long-term effectiveness of this approach and its potential to reduce or eliminate the need for immunosuppressant drugs.


1.    Source: Coherent Market Insights, Public sources, Desk research
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