Graft Versus Host Disease
Graft-versus-host disease is a complication of allogeneic bone marrow transplantation and some other types of solid organ transplantation. After transplantation, T cells present in the graft tissue attack the tissues of the transplant recipient. The T-cells attack because they view the new recipient tissues as foreign antigen. Essentially, graft-versus-host-disease is a pathological condition in which cells from donor tissues and organs initiate an immunologic attack on the cells and tissue of the recipient.
- Graft-versus-host-disease (GVHD) is divided into acute and chronic forms. The acute or fulminant form of the disease is observed within the first 100 days post-transplant, and the chronic form of GVHD is defined as that which occurs after 100 days. Acute and chronic graft-versus-host-disease appear to involve different immune cell subsets and different types of target organ damage.
- Classically, acute GVHD is characterized by selective damage to the liver, skin, mucosa, and the gastrointestinal tract. Chronic GVHD damages the above organs, but also causes changes to the connective tissue (e.g. of the skin and exocrine glands).
- GVHD of the GI tract can result in diarrhea, abdominal pain, nausea, vomiting. It is diagnosed with a biopsy of the intestinal lining.
- Liver GVHD is diagnosed by measuring bilirubin levels.
- Skin GVHD results in a generalized rash that is red and raised in acute GVHD. In chronic GVHD, the skin can become firm (sclerotic) and hyperpigmented. The skin may become so inelastic in chronic GVHD that contractures develop around joints that significantly limit movement. This form of chronic GVHD is termed “sclerodermoid” because it resemble the connective tissue disease, scleroderma.
- Skin biopsies of GVHD may or may not be helpful in making the diagnosis, but they are generally performed to assist physicians when there is clinical suspicion of GVHD.
- The treatment of acute GVHD is generally combination immunosuppressant regimens, plasmapheresis or both.
- The treatment of chronic GVHD is the same as above, but it may also be very helpful to combine these regimens with phototherapy (UVA-1 or narrowband UVB).