Organ Transplant Rejection

Organ transplant rejection occurs when a patient’s immune system recognizes the transplanted organ as foreign and attacks it. This happens because the immune system is designed to protect the body from harmful substances, including bacteria and viruses. In the case of a transplant, the new organ may have different markers, known as antigens, that the immune system identifies as threats. Rejection can be acute (occurring soon after the transplant) or chronic (developing gradually). To prevent rejection, doctors prescribe immunosuppressive medications, which help the body accept the new organ by dampening the immune response.