The significance of angiotensin II type 1 receptor (AT1 receptor) in renal transplant injury.

Humoral response beyond human leukocyte antigen (HLA) is of great interest in the transplant community. We decided to summarize the data on a new antigenic target called angiotensin II type 1 receptor (AT1 receptor). Non-HLA antibodies can now be detected in routine clinical care of patients after transplantation, but their role is not fully understood. Numerous analyses showed that non-HLA response may exert a higher risk of allograft rejection and allograft loss independently of the HLA system. Non-HLA response may even have a higher rate of antibody-mediated rejection. Information regarding antigen target, as well as the pathophysiology of its antibodies and diagnostic tools, is essential for a better understanding of non-HLA humoral response. Angiotensin II type 1 receptors are the most recognized target for non-HLA antibodies. Anti-AT1R Abs (anti-angiotensin II type 1-receptor-activating antibodies) may identify renal transplant patients at higher risk of graft rejection and loss. The presence of AT1 receptor expression analyzed together with anti-AT1R Abs should be considered for better transplant immunological risk assessment. Further assessment is required for a better understanding and to create appropriate therapeutic strategies.