Prévention des insultes immunologiques aux greffes renales

 

Ruth Sapir-Pichhadze

Institut de recherche du Centre universitaire de santé McGill

 

Domaine : santé des populations

Programme Chercheurs-boursiers cliniciens - Junior 1

Concours 2018-2019

Kidney transplantation saves the lives of patients with kidney failure. While on the waiting list for a transplant, patients undergo a test called human leukocyte antigen (HLA) typing. This test identifies blood proteins called HLA, that are located on the cell surface and help differentiate between "self" and "non-self." When the immune system recognizes something that does not belong to it like bacteria or virus invasion, it attacks it. Similarly, the immune system attacks HLA on transplanted organs when it recognizes donor HLA as different. This is called rejection. On the other hand, when donors and patients share HLA, they are said to be a match, and rejection is less likely to occur.

It is difficult to achieve a perfect HLA match between donors and recipients. Consequently, to decrease the risk of rejection, transplantation is pursued only when recipients do not have pre-existing antibodies against donor HLA. This strategy, however, does prevent new antibodies from forming following transplantation. New antibodies against donor HLA develop in response to non-self-epitopes within HLA molecules. Epitopes are smaller pieces of the HLA protein that are significantly different from person to person. Some mismatches between donor and recipient epitopes may result in antibodies more frequently than others.

Our goal is to better characterize epitopes that are likely to result in antibodies and rejection. We will assess whether this risk changes depending on the patients' exposure to medication suppressing the immune system. In the future, this information can guide how to match patients with donors against whom they are less likely to experience rejection, and allow kidney transplants to serve patients for their entire lifetime.