In France, nearly 4,000 kidney transplants are performed on average each year. Kidney transplantation is the only curative treatment for people suffering from end-stage renal failure, but this intervention is not always successful because the graft can be rejected by the patient's body. In order to reduce the risk of rejection, doctors can now take an interest in a certain number of genetic and immunological parameters to assess the rate of compatibility between two organs or tissues between donor and recipient (we speak of histocompatibility). In a new study, scientists have shown that the MICA gene is a new histocompatibility gene. Taking an interest in it makes it possible to better explain and predict the success or failure of a kidney transplant. The team here studied the MICA gene in more than 1,500 patients who had received a kidney transplant as well as in their donors. Sequence analyzes of the MICA gene show that when the recipient and the donor present a different version of the gene, the survival of the graft is reduced. These results also prove that the MICA gene would be a relevant histocompatibility gene to be taken into account at the time of a transplant, and that the search for anti-MICA antibodies can be interesting to predict the success or failure of the transplant. Caption: Histological images of antibody-mediated kidney transplant rejection. Credits: Sophie Caillard/Jérome Olagne (Inserm U1109). Sources: The MHC class I MICA gene is a histocompatibility antigen in kidney transplantation, Nature Medicine, March 2022 DOI: https://go.nature.com/3KEMfBp
