One of the main issues surrounding stem cells, and specifically surrounding stem cell transplants, is the rate of incidence of Graft-Versus-Host-Disease (GVHD). Also linked to cancer treatment, GVHD can have serious side effects. But what exactly is GVHD, what are the causes of Graft-Versus-Host-Disease and how can GVHD be prevented?
What is GVHD? The Causes of GVHD
Graft-Versus-Host Disease is a potentially fatal immune system reaction that occurs in response to a stem cell transplant or a bone marrow transplant of cells from either a related or non-related (allogeneic) donor.
GVHD occurs when the cells of the donor imperfectly match the immune system characteristics (markers) of the host recipient. When this happens, the T-cells of the donor’s body (white blood cells that are immune cells) attack new cells in the host recipient’s body. The immune system of the host recipient will respond using HLA antigens which function to identify which cells belong to the body and which are foreign to it. The antigend will attack the latter. In GVHD, the donor’s immune cells (T-cells) are unable to recognize the HLA antigens found on the cells of the host recipient’s body, causing them to attack the cells.
Types of GVHD: Acute Versus Chronic GVHD
There are two types of Graft-Versus-Host-Disease: acute GVHD and chronic GVHD.
- acute GVHD: in cases of acute GVHD, symptoms appear within 3 months of a transplant. Symptoms can include a reddish skin rash, as well as nausea and diarrhea. If the liver is affected, the skin can become yellow in appearance. Acute GVHD can become:
- chronic GVHD: in cases of chronic GVHD, symptoms appear 3 months after the transplant surgery. Symptoms of chronic GVHD are rated on a scale from 1 (mild) to 4 (severe). Symptoms are similar to those experienced in individuals with acute GVHD and can also include abnormalities of the salivary glands in the mouth (i.e. dry mouth) and the mucous glands of the eyes (dry, irritated eyes). Chronic GVHD can last from several months to many years.
Signs and Symptoms of GVHD
Here is an overview of GVHD symptoms:
Acute GVHD Symptoms
- skin rash that is reddish in appearance
- abnormal liver function
- yellowing of the skin
- increased susceptibility to infection
Chronic GVHD Symptoms
- skin rash or change in skin color or texture
- dry, irritated eyes
- sensitive or dry mouth
- thinning hair
- brittle nails
- dry, irritated vaginal region
- loss of appetite
- sudden weight loss
Symptoms of GVHD can range from mild to severe.
Generally, individuals who have received a stem cell transplant or a bone marrow graft are monitored closely for any signs of complications, including GVHD.
However, if you experience any of the above symptoms, be sure to contact your health care provider immediately.
The treatment of GVHD includes the use of immunosuppressive drugs, mainly steroids, which are administered as early as possible in order to strengthen the individual’s immune system. Both acute and chronic GVHD are treated in this manner. The side effects associated with this type of treatment can include anxiety, depression and weight gain.
The main method used to prevent graft-versus-host-disease is the use of immuosuppressive drugs, which are administered to minimize the immune system’s response to foreign cells in the body. These drugs are carefully administered so as not to cause damage to the body. Long-term side effects of this type of GVHD prevention methodare:
- sensitivity to the sun
- cavities and gum disease
- dry, irritated eyes
- diarrhea and other digestive problems
In addition, the closest donor match possible is always made in order to prevent cell transplant rejection. Whenever possible, a family donor is used so as to decrease the risk of GVHD. ABO (blood group) and HLA (tissue antigen) typing are also used to ensure as close an antigenic match as possible.
Umbilical cord blood is also sometimes used in order to prevent GVHD, because cord blood cells are more primitive and therefore do not usually result in GVHD. In fact, a recent study regargding recipients of transplants donated from siblings for cord blood and bone marrow transplants found that the recipients of cord blood transplants were 59% less likely to develop GVHD.
In some cases, T-cells are removed prior to transplants in order to reduce the risk of Graft-Versus-Host Disease.
Some of the possible complications associated with GVHD include infection, as well as moderate to serious liver, lung and gastrointestinal tract damage.
For information on cord blood banking, click here.