A recent study shows that infection with Pseudomonas aeruginosa may trigger pulmonary transplant rejection, but researchers have also identified a potential solution to prevent this phenomenon.
Connection between lung transplantation and a bacterial infection. Photo: Shutterstock
According to MedicalXpress, a group of American researchers has discovered a connection between infection with Pseudomonas aeruginosa and rejection of transplanted lungs. Their study, published in the prestigious Journal Science Translational Medicine, analyzes the medical history of patients who have undergone pulmonary transplant and highlights an unexpected correlation between the presence of the bacterium and the rejection of the transplant.
For patients with severe lung disease, a lung transplant is often the last hope to regain an improved quality. However, even after the transplant, fear that the body rejects the new organ persists, and the success rates of pulmonary transplants remain among the lowest compared to other types of transplants.
Initially, the researchers analyzed the medical files of the patients who received a pulmonary transplant, looking for cases where the infection with Pseudomonas aeruginosa and the rejection of the transplant appeared simultaneously. The results showed that the frequency of rejection was higher than anticipated, which is why the team decided to carry out experiments on laboratory mice.
In the experiments carried out, the mice, which were healthy, were infected with Pseudomonas aeruginosa and subsequently transplanted the lungs from other mice. The monitoring of their evolution revealed that the bacteria was spreading in the lymphoid tissues, where it destroyed the CD4+cells. This destruction caused an increase in the number of B cells that expressed the CXCR3 protein. The B cells, sensitized to antigens in donated lungs, began to produce specific antibodies to the donor, thus triggering the mechanism of rejection of the transplanted organ.
Another important aspect of the study was the discovery that the administration of drugs that block the expression of CXCR3 protein at B cells can inhibit the rejection mechanism. In mice experiments, treatment allowed to maintain the function of new lungs, suggesting a possible therapeutic approach for pulmonary transplant patients.
The discovery of the connection between the infection with Pseudomonas aeruginosa and the rejection of the pulmonary transplant opens new directions to prevent post-transplant complications. If the experimental results will also be confirmed in people’s clinical studies, blocking the expression of CXCR3 protein could become a valuable strategy in the management of patients with lung transplant.
