Graft-versus-host disease (GVHD) is a complication that can occur after a stem cell or bone marrow transplant (BMT) that uses donor cells. This type of transplant is called an allogeneic transplant. “Graft” refers to the immune cells from a donor. “Host” refers to the person who gets the transplant.

What causes graft-versus-host disease?

GVHD happens when donor immune cells identify the host’s tissue as foreign and begin to attack it.

What parts of the body can be affected by graft-versus-host disease?

GVHD can affect many parts of the body, including the eyes, skin, and mouth, as well as such organs as the gastrointestinal tract (gut), liver, and lungs. GVHD is one of the most serious complications of an allogeneic BMT.

GVHD may be acute. This means it comes on suddenly. Acute GVHD usually occurs within the first three months after a transplant.

GVHD can also be chronic. That means it may linger, possibly for years. Chronic GVHD can happen two to three months after a transplant and can continue to come back for several years after the procedure.

Between one-third and two-thirds of all people who have an allogeneic transplant will eventually develop some symptoms of GVHD. Chronic GVHD is a bit more common than acute GVHD.

People are more likely to develop GVHD if their donor was not a perfect match, if their donor was not related to them, if they or their donor are older, or if they have been pregnant.

Not all of the effects of GVHD are bad. People with GVHD are also more likely to experience the graft-versus-tumor effect. This is when the immune cells from the donor attack the remaining cancer cells in the body. For this reason, people who have a history of GVHD have lower rates of the cancer coming back.

GVHD is diagnosed based on symptoms, as well as the results of laboratory tests and tissue samples.