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:
- Bathing or showering daily
- Carefully cleaning your teeth and gums
- Cleaning the area where your central line enters your body
- Avoiding foods that may have harmful bacteria, such as raw fruits and vegetables
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:
- A rash that starts on the palms of your hands and soles of your feet and spreads to your mid-section. Over time, the rash may cover your entire body. Skin can blister or peel if the rash is very bad.
- Nausea (feeling sick to your stomach), vomiting, loss of appetite, stomach cramps, and diarrhea. Doctors determine how bad GVHD is based on the severity of diarrhea.
- Jaundice (yellowing of the skin and whites of the eyes) and stomach pain. These symptoms indicate liver damage.
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:
- Closely matching your stem cells to your donor's through HLA tissue typing.
- Using medicines to suppress your immune system.
- Removing some types of T cells from donor cells. In GVHD, T cells attack your body.
- Using umbilical cord blood as the source of donor cells.
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.