Graft-versus-host disease (GVHD) is a condition that can occur after a bone marrow transplant.

See also: Transplant rejection

GVHD occurs in a bone marrow transplant involving a donor and a recipient. The bone marrow makes all types of blood cells, including white cells that are responsible for the immune response. Since only identical twins have identical tissue types, the donor's bone marrow is normally a close, but not perfect, match to the recipient's tissues. See: Histocompatibility Antigen Test

The differences between the donor's marrow and recipient's tissues often cause T cells (a type of white blood cells) from the donor's marrow to recognize the recipient's body tissues as foreign. When this happens, the newly transplanted bone marrow attacks the transplant recipient's body.

Acute GVHD starts within the first 3 months after transplant. Chronic GVHD starts more than 3 months after transplant, and can last for as long as 3 years.

Rates of GVHD vary from between 30-40% among related donors and recipients to 60-80% between unrelated donors and recipients. The greater the mismatch between donor and recepient, the greater the risk of GVHD. After a bone marrow transplant, the recipient usually takes drugs that suppress the immune system, which helps reduce the chances (or severity) of GVHD.

Symptoms in both acute and chronic GVHD range from mild to severe.

Common acute symptoms include:

• Abdominal pain or cramps
• Diarrhea
• Fever
• Jaundice
• Skin rash
• Vomiting
• Weight loss

Chronic symptoms may include:

• Dry eyes and dry mouth
• Hair loss
• Hepatitis
• Lung and digestive tract disorders
• Skin rash

In both acute and chronic GVHD, the patient is very vulnerable to infections.

The tests done usually depend on the symptoms, but may include:

• Gastrointestinal endoscopy, with or without a biopsy
• Liver function tests (AST, ALP, and bilirubin levels will be increased)
• Liver biopsy (if the patient only has liver symptoms)
• Lung x-rays
• Skin biopsy