Cord Blood Transplant Complications: Graft-Versus-Host-Disease (GVHD)
One of the main concerns people have surrounding
stem cells, and more specifically, stem cell transplants, is the possibility of contracting Graft-Versus-Host-Disease (GVHD). This transplant complication can lead to potentially serious complications, including damage to the liver, lungs and gastrointestinal tract. But what exactly is GVHD, and how can it be prevented?
What is GVHD?
Graft-Versus-Host Disease occurs when the body does not recognize the immune cells (or T cells) of the stem cell donor during a stem cell or bone marrow transplant from either a related or non-related (allogenic) donor.
Your body uses markers called HLA antigens to determine which cells are foreign to the body. Once it has determined that a cell does not belong in the body, it will begin to attack it. In GVHD, the donor’s immune cells are not recognized by the HLA antigens, causing them to attack the cells. That is why finding a well-matched donor is so crucial.
Types of GVHD: Acute Versus Chronic GVHD
This form of GVHD begins to appear within three months of the transplant, and can range from mild to life-threatening. The types of symptoms a patient will experience will depend on which part of the body has been infected. Typical symptoms can include a skin rash, nausea, and diarrhea. Yellowed skin may also appear if the liver has been affected.
Chronic GVHD can start to appear any time after the three months post-transplant. People with acute GVHD are more likely to get chronic GVHD, although GVHD can also affect patients with no history of the disease. Symptoms of chronic GVHD range in severity, and are rated on a scale of 1 to 4, with 4 being the most severe. These symptoms tend to be similar to those associated with acute GVHD, although chronic GVHD can also cause dryness in the salivary glands as well as the mucous glands of the eyes. The disease can last for a period of several months to several years.
Some less common symptoms associated with chronic GVHD include:
- thinning hair
- brittle nails
- dry, irritated vaginal region
- loss of appetite
- sudden weight loss
It is recommended that patients undergoing a stem cell or bone marrow transplant properly protect themselves from the sun, as this has been known to trigger GVHD. Proper sun protection includes regular application of a sunscreen with SPF 15 or higher, as well as wearing protective clothing and hats, even on cloudy days.
Generally speaking, anyone who has received a stem cell transplant or a bone marrow graft will be closely monitored for any signs of complications, including GVHD.
However, if you experience any of the above symptoms, it is important that you contact your health care provider immediately.
How to Treat GVHD
It is important that treatment of GVHD begin as early as possible, so that any further complications may be avoided. Both types of the disease are treated primarily through the use of steroids – most commonly prednisone and/or cyclosporine – in order to weaken the immune system.
To prevent GVHD, doctors primarily rely on the use of immunosuppressive drugs, such as steroids, to lessen the immune system’s response to any foreign cells in the body. In addition, it is crucial that doctors locate the closest donor match possible to prevent rejection. To do this, ABO (blood group) and HLA (tissue antigen) typing are used to ensure the antigenic match is as close as possible.
Another way patients can significantly reduce their risk of contracting GVHD is through the use of stem cells derived from umbilical cord blood. This is because cord blood cells are more primitive and therefore do not usually result in GVHD. In fact, a recent study found that the recipients of cord blood transplants were 59% less likely to develop GVHD than those who had undergone stem cell or bone marrow transplants.
Finally, in some cases, T-cells are removed prior to transplants in order to reduce the risk of Graft-Versus-Host Disease.
Potential Risks and Side Effects
Unfortunately, the medication used to treat and prevent this condition is associated with a number of side effects. The most significant of these is an increased susceptibility to infection, since both the steroids and GVHD serve to weaken the immune system. Other potential side effects include:
- depression or anxiety
- mood swings
- weight gain
- bloated or round face
- hair growth, particularly on the face and back
In addition to the side effects mentioned above, some long-term side effects associated with GVHD treatment and prevention are:
- sensitivity to the sun
- cavities and gum disease
- dry, irritated eyes
- diarrhea and other digestive problems
Other possible complications associated with GVHD include infection, as well as moderate to serious liver, lung and gastrointestinal tract damage.