Organ Transplantation and Artificial Organs

Transplant Rejection

Immune system usually protects you from substances that may be harmful, such as germs, poisons, and sometimes, cancer cells. These harmful substances have proteins called antigens coating their surfaces. As soon as these antigens enter the body, the immune system recognizes that they are not from that person's body and that they are foreign, and attacks them. When a person receives an organ from someone else during transplant surgery, that person's immune system may recognize that it is foreign. This is because the person's immune system detects that the antigens on the cells of the organ are different or not matched. Mismatched organs, or organs that are not matched closely enough, can trigger a blood transfusion reaction or transplant rejection.