A number of complications might happen after an allogeneic transplant. Most of them can be prevented, managed, or treated.
Graft-versus-host disease (GVHD) can happen if white blood cells that have formed from the donor’s stem cells recognize the patient’s cells and tissues as foreign and attack them.
If a donor’s and a patient’s tissue types don’t completely match, there is a greater risk of GVHD. The disease may also be more severe if it does occur. Factors such as the age and gender of the patient and the donor and the intensity of the treatments that the patient has before transplantation also determine the risk of GVHD.
GVHD can be either acute or chronic. Acute GVHD occurs within a few weeks; chronic GVHD begins later and lasts longer. Symptoms of acute disease include skin rash and intestinal or abdominal pain. This is caused by an inflammation of the liver and the lining of the intestine. In people with GVHD, it may take more time for the immune system to rebuild itself.
Doctors may give drugs such as methotrexate (Rheumatrex®, Trexall®) or cyclosporine (Gengraf®, Neoral®, Sandimmune®) to prevent acute GVHD from occurring. Drugs called steroids may also be given to control GVHD.
Sometimes, the donor’s stem cells fail to grow and replace the patient’s blood cells after the transplant. This is called graft failure. The most common cause is that the patient’s immune system recognizes the donor’s cells as foreign and attacks them. This may happen if the chemotherapy and radiation given before the transplant were not able to fully shut down the patient’s immune system.
Graft failure can also be caused by infections with certain viruses. Better ways to prevent, find, and treat these infections are reducing graft failure caused by viral infections.
The risk of graft failure generally lasts about two to four weeks after the transplant. It can occasionally happen later on. If there is a graft failure, doctors may recommend transplanting more donor stem cells, if they are available.
Complications of High-Dose Therapy
People who get high doses of chemotherapy or radiation therapy may have short-term or long-term complications. These can include infections, bleeding, and anemia. Complications come up during the time before a patient’s blood cell production returns to normal. Organ problems can also happen after a transplant. There are treatments for these side effects that help many people.
Another possible complication is mucositis. In this condition, the cells that line the mouth and intestinal tract are destroyed by the high-dose chemotherapy or radiation therapy given before the transplant. Symptoms include mouth pain and ulcers, abdominal pain, diarrhea, and infections. Mucositis may not last as long in some people who take a new drug called recombinant human keratinocyte growth factor (rHuKGF).
For some people, there is a chance that their cancer can come back after a stem cell transplant. This is a particular risk if the disease was in an advanced stage or had already come back at the time of the transplant. Cancer can return if the chemotherapy and radiation given before the transplant did not get rid of all the cancer cells.
At Memorial Sloan Kettering, our team of doctors closely follows people who have had a transplant. We watch for any signs of the disease coming back. If the cancer does return, we will change the treatment strategy.
In rare instances, people who have had a transplant may get a secondary cancer such as leukemia or a myelodysplastic syndrome. This may be caused by the treatments they were given before their transplant.