After a donor stem cell transplant, the donor’s stem cells (the graft) may sometimes react against your own cells (the host). This is called graft-versus-host disease (GVHD). It happens when the donor’s cells, usually a white blood cell (called a T-lymphocyte or T-cell) attack your body's cells.
GVHD does not mean the transplant has failed, and it can even have benefit. The donor cells may also attack any cancer or leukaemia cells that survived the conditioning treatment.
There are two forms of GVHD:
- Acute GVHD
This usually develops within the first 100 days (about 3 months) after transplant but it may also happen after this time.
- Chronic GVHD
This can start on its own a few months after transplant. Or, it can sometimes progress from the acute type.
The risk is linked with how closely you and your donor match. People who have unrelated or mismatched donors, or have had a donor lymphocyte infusion, are more at risk.
The effects of GVHD are usually mild. But in some people they can be severe and even life-threatening. It mainly affects the skin, mouth, stomach, bowel and liver.
Preventing acute GVHD
Your doctors will give you immunosuppressive drugs to reduce your risk of acute GVHD after your transplant. They help stop your donor’s T-cells attacking your body tissues.
Different drugs can be used. You may have either ciclosporin or tacrolimus. They are often given along with other drugs such as methotrexate or mycophenolate. You carry on taking them when you go home from hospital. It is very important to take your immunosuppressive drugs.
If the risk of severe GVHD is very high, the donor’s T-cells can be removed from the stem cell collection in the laboratory. This could be when stem cells from a mismatched unrelated donor or haploidentical donor are used.
Symptoms of acute GVHD
The symptoms depend on which part or parts of your body are affected. It often causes an itchy skin rash. If your bowel, stomach or liver are affected, you may have sickness and diarrhoea. If the liver is affected, sometimes the whites of your eyes become yellow (jaundiced).
Acute GVHD is graded by how severe it is. It goes from grade 1, which is mild, to grade 4 which is very severe. If it is mild, you may not need treatment other than steroid cream for your skin. But if it is grade 2 or above, you will usually need treatment with steroids to suppress the immune reaction. You may need to be admitted to hospital for monitoring and support with the symptoms.
This may happen more than 3 months after transplant. It can develop from acute GVHD or happen on its own. Your transplant team will explain what to look out for.
Any symptoms will depend on which parts of the body are affected. They may include:
- skin changes, including dryness, flaking, discoloration and ulcers
- hair that grows slowly and is brittle or patchy
- feeling short of breath or wheezy
- a dry and swollen mouth and mouth ulcers
- dry, gritty eyes
- diarrhoea, stomach cramps, sickness and loss of appetite
- vaginal narrowing and dryness
- repeated infections
- muscle weakness and joint pain.
Chronic GVHD is usually treated with steroids and other treatments that help control the immune system. You will also be given treatment and support to manage any symptoms you have.
Extracorporeal photopheresis (ECP) - light treatment
Extracorporeal photopheresis (ECP) is when your blood cells are treated outside your body with special light treatment. Doctors are not sure exactly how it works to treat GVHD. But they know that it changes the immune system without weakening it.
ECP is used more for chronic GVHD, and most people's symptoms improve. Your doctor or nurse will give you more information about the treatment. It is only available in some specialist centres.
Your central line is connected by tubes to a cell separator machine. Blood leaving your body passes through the machine and is treated with ultraviolet (UV) light and drugs that work when exposed to light.
The treated blood is then returned to you by another tube that also connects to your central line. This continues until all your blood has been treated. You normally have it 2 days in a row every 2 to 4 weeks.