Non-HLA antibodies in transplantation refer to antibodies that target antigens other than the human leukocyte antigen (HLA) system. These antibodies can play a significant role in transplant rejection, graft failure, and immune responses following organ transplantation. While HLA antibodies are well-known for their role in graft rejection and compatibility testing, non-HLA antibodies are becoming increasingly recognized for their potential impact, especially in the immediate post-transplant period.