Graft-vs.-Host Disease

Overview :

The main problem with transplanting organs and tissues is that the recipient host does not recognize the new tissue as its own. Instead, it attacks it as foreign in the same way it attacks germs, to destroy it.

If immunogenic cells from the donor are transplanted along with the organ or tissue, they will attack the host, causing graft vs. host disease.

The only transplanted tissues that house enough immune cells to cause graft vs. host disease are the blood and the bone marrow. Blood transfusions are used every day in hospitals for many reasons. Bone marrow transplants are used to replace blood forming cells and immune cells. This is necessary for patients whose cancer treatment has destroyed their own bone marrow. Because bone marrow cells are among the most sensitive to radiation and chemotherapy, it often must be destroyed along with the cancer. This is true primarily of leukemias, but some other cancers have also been treated this way.