Antibody-mediated rejection (AMR) is a type of rejection that occurs in solid organ transplantation, such as kidney, heart, or lung transplantation, where the recipient's immune system produces antibodies that target the transplanted organ. These antibodies can lead to damage of the transplanted organ and ultimately result in rejection. AMR can occur acutely or chronically and is often more difficult to treat than other types of rejection. Diagnosis of AMR typically involves identifying the presence of donor-specific antibodies in the recipient's bloodstream and assessing levels of inflammation and injury in the transplanted organ. Treatment usually involves a combination of immunosuppressive drugs and therapies aimed at reducing antibody levels. Early detection and management of AMR are crucial for the long-term success of organ transplantation.