Graft-Versus-Host Disease

Graft-versus-host disease (GVHD) is a common side effect of an allogeneic bone marrow or cord blood transplant (also called a BMT). An allogeneic transplant uses blood-forming cells donated by a family member, unrelated donor or cord blood unit. In GVHD, the immune cells from the donated marrow or cord blood (the graft) attack the body of the transplant patient (the host). GVHD can affect many different parts of the body. The skin, eyes, stomach and intestines are affected most often. GVHD can range from mild to life-threatening. VHD occurs because some of your donor's immune cells (known as T cells) attack cells in your body. The immune system uses markers called HLA antigens to recognize which cells belong in your body and which do not. When it finds cells with HLA antigens it does not recognize, it attacks those cells. In GVHD, your donor's immune cells do not recognize the HLA antigens on your body's cells, so they attack your cells. That is one reason your donor's HLA antigens need to match yours as closely as possible. Selecting a closely matched donor or cord blood unit can help reduce your risk of getting GVHD. Doctors have found several ways to help reduce the risk a transplant patient will get GVHD: * Using a closely matched donor or cord blood unit. * Using umbilical cord blood — after a cord blood transplant fewer patients get GVHD and those who do tend to get less severe GVHD. * Using drugs to prevent GVHD — you will be given drugs to help prevent GVHD. These drugs work well for many patients. Some examples of drugs often used for this include cyclosporine and methotrexate. * Removing the T cells from the donated cells before transplant — the T cells are the immune cells that attack your body when you get GVHD. New methods of removing some T cells from the donor's cells before the transplant may reduce the risk of GVHD.