During the first 6 weeks after transplant, until the new bone marrow starts making white blood cells (engraftment), the patient can easily get infections. Bacterial infections are the most common during this time. Blood-forming growth factor drugs may decrease this period of danger.

After engraftment, the risk of infection drops, but it remains a potential problem. It takes 6 months to a year after a transplant for the immune system of most patients to work as well as it should. It can take longer for patients with GVHD.

Because of the increased risk, patients are closely watched for signs of infection such as a fever, and extra precautions are taken. Anyone who enters the patient’s hospital room must wash their hands thoroughly as hands are the main carriers of infection. They must also wear gowns, gloves, and masks. Since flowers and plants can harbor bacteria and fungi, they are not allowed in the patient’s room. For the same reason, fresh fruits and vegetables must not be eaten and all food must be well cooked. Other dietary restrictions might also be started.

Despite all these precautions, patients often develop fevers, one of the first signs of infection. If this occurs, antibiotics will be started right away.

After a transplant, a recipient is at risk for bleeding because the conditioning treatment destroys most of the body’s platelet supply. Platelets are the blood parts that help blood to clot. A low platelet count usually lasts at least 3 weeks after the transplant. In the meantime, bleeding, such as nosebleeds, bleeding gums, and bruising may occur. If the platelet count drops below 20,000/mm3, a transfusion of platelets may be needed.

It also takes time for the bone marrow to begin making red blood cells, and transfusions may be needed from time to time during the recovery period.

This type of pneumonia is most common in the first 100 days after a stem cell transplant. It may be caused by a virus or by radiation or chemotherapy. It is a nonbacterial, nonfungal form of pneumonia that penetrates the interstitial spaces (areas between the cells) of the lungs. Chest x-rays will be taken in the hospital to watch for signs of pneumonia.

GVHD occurs in allogeneic transplants when the donor immune cells view the recipient’s body as foreign. (The recipient’s immune system has largely been destroyed by conditioning treatment and cannot fight back.) The donor immune cells may attack certain organs, most often the skin, gastrointestinal tract, and liver. This can impair the organs’ ability to function and increase the chances of infection. Acute GVHD may occur 10 to 70 days after a transplant, though the average time is around 25 days.

About one third to one half of allogeneic transplant recipients develop acute GVHD. It is less common in younger patients and in those with better HLA matches between donor and recipient. Most cases are mild, and those who develop it usually have no long-term effects, although in some cases it can be serious or even life threatening. Doctors try to prevent acute GVHD by giving drugs to lessen the immune response, such as steroids, methotrexate, cyclosporine, and tacrolimus. Although these help prevent serious GVHD, mild GVHD will almost inevitably occur.

This complication is not expected in syngeneic or autologous transplant patients.

Chronic (ongoing) GVHD can occur anywhere from about 70 to 400 days after the stem cell transplant. A rash on the palms of the hands or the soles of the feet is often the earliest sign. The rash can spread and is usually itchy and dry. In severe cases, the skin may peel, like after a bad sunburn. A fever may also develop. Other symptoms of GVHD can include:

• decreased appetite
• diarrhea
• abdominal cramps
• weight loss
• jaundice (yellow color of the skin)
• enlarged liver
• bloated abdomen
• pain in the upper right part of the abdomen
• increased levels of liver enzymes in the blood
• a tight feeling to the skin
• dry, burning eyes
• dryness or sores in the mouth
• burning sensations when eating acidic foods
• bacterial infections

Chronic GVHD is treated with medicines that suppress the immune system, similar to those used for acute GVHD. The risk of GVHD can be decreased by removing some immune cells (known as T-cells) from the donor stem cells before the transplant. This can also increase the risk of graft failure though (see below).

Graft failure happens when the body does not accept the new stem cells (the graft). Graft failure is more common in patients whose donor marrow is not well matched and in patients who receive bone marrow that has had T-cells removed, but in general, it is a rare occurrence.

Revised 09/04