The main risks of a blood and marrow stem cell transplant are infections, graft-versus-host disease (GVHD), and graft failure.
You can easily get infections after the transplant because your immune system is weak. The risk of infections decreases as your immune system recovers.
You can take steps to prevent infections, such as:
Transplant recipients sometimes are given vaccines to prevent viruses and infections, such as the flu and pneumonia. If you develop an infection, your doctor will prescribe medicine to treat it.
GVHD is a common complication for people who get stem cells from a donor. In GVHD, the new stem cells attack your body.
Acute GVHD occurs within 90 to 100 days of the transplant. Chronic GVHD begins more than 90 to 100 days after the transplant or goes beyond 90 days after the transplant.
GVHD can be minor or life threatening. Signs and symptoms include:
Doctors prescribe medicines to treat GVHD. Acute GVHD is treated with glucocorticoids, such as methyl prednisone, prednisone in combination with cyclosporine, antithymocyte globulin, or monoclonal antibodies.
Chronic GVHD is treated with steroids—usually cyclosporine and prednisone on alternating days.
Older people, people who have had acute GVHD before, and people who receive stem cells from mismatched or unrelated donors are at increased risk for GVHD.
Doctors can reduce your chances of getting GVHD by:
Graft failure occurs if your immune system rejects the new stem cells. It also can occur if not enough stem cells are used, the new stem cells are damaged during storage, or your bone marrow is damaged after the transplant.
Graft failure is more likely to occur in people who receive less preparation for their transplants. People who get stem cells from poorly matched donors also are more likely to have graft failure.
The chemotherapy and/or radiation you receive during transplant preparation can cause complications. Sometimes these complications occur long after the transplant.
Complications can include infertility, cataracts, new cancers, and damage to the liver, kidneys, lungs, or heart.
In some people who get stem cell transplants to treat cancer (such as leukemia), the cancer eventually comes back. This happens more often in people who use their own stem cells for the transplant (an autologous transplant) than in people who get stem cells from a donor (an allogenic transplant).
This difference occurs because stem cells received from another person recognize new cancer cells as foreign and destroy them. This is called the graft-versus-tumor effect. A person's own stem cells don't recognize the new cancer cells as foreign. This allows the cancer cells to grow and multiply.
Doctors use immunotherapy to help prevent or treat the recurrence of cancer in people who have had stem cell transplants. This treatment stimulates the immune system to attack cancer cells.
Clinical trials are research studies that explore whether a medical strategy, treatment, or device is safe and effective for humans. To find clinical trials that are currently underway for Blood and Marrow Stem Cell Transplant, visit www.clinicaltrials.gov.
The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.