This four-part series is written by Edward Agura, MD, an advisory panel member for the Cancer.Net Editorial Board. Dr. Agura is Director of the Program in Blood and Marrow Transplant at Baylor University Medical Center in Dallas, Texas.

This is the third in a four-part series of articles on bone marrow and stem cell transplantation. The series will prepare you to ask your transplant team meaningful questions and help you to understand the answers. This article addresses the most common side effects experienced by people having a transplant.

Infection

We live in a world surrounded by living microscopic organisms called bacteria, fungi, and viruses. During transplant treatment, the body's natural defenses against these organisms are lowered, and infection and illness may result.

A common misunderstanding is that the greatest danger from infection during early phases of a transplant comes from the outside world and from other people; this is not true. Most infections occurring during the first four weeks of a transplant are due to organisms that are already in the patient's body. Hiding places, in the lung, sinuses, skin, and the intestines, allow germs to go undetected, and then cause an infection during a period of low immunity. Fortunately, most of these germs are relatively easy to kill with modern antibiotics. The reduced immunity of the early transplant period lasts about two weeks, after which the immune system is back to near full-fighting strength, at which time most common germs are kept at bay by the patient's own immune system.

However, a small danger of infection remains for both autologous (AUTO) and allogeneic (ALLO) transplant recipients beyond this early stage. The danger is greatest if a patient is taking medications to suppress the immune system or if graft-versus-host disease (GVHD, see below) is present. During this time, there is a real danger of getting germs from other people through the air by sneezes and coughs, by handshakes, and from food. There is a further danger from inhaling dust, bacteria from bird droppings, and cigarette smoke. A major lifestyle change is required for many people, so these exposures can be avoided. Those with pets may have to avoid them, smokers will need to quit, and a person may even need to change their workplace, such as avoiding farming.

Patients should talk with their doctors about how long precautions should be taken.

Graft-versus-host disease

The unusual post-transplant illness known as GVHD occurs following an ALLO transplant only, when the donated bone marrow comes from another person. As a general rule, patients who've had an AUTO transplant do not develop this problem.

GVHD is a form of immune system-mediated attack that may occur following solid organ transplantation such as heart, kidney, or liver transplantation. The difference is that following ALLO transplantation, the "target" of the immune attack, is the patient’s entire body rather than any one particular organ. The attacking immune system is derived from the newly infused (transfused) bone marrow from the donor. The illness that may (or may not) result is called GVHD.

Patients who have small amounts of GVHD have a reduced rate of recurrent cancer. They are cured more often. On the other hand, patients with severe GVHD may become seriously ill and may die.

Doctors try to prevent severe GVHD from occurring. This is best accomplished by the choice of donor. Having a perfectly matched donor (either a brother or sister, or a DNA sequence-matched, unrelated donor) results in the lowest chance of severe GVHD. Using other types of donors causes a higher risk of GVHD. However, usually donor choice is dictated by circumstances beyond the patient's control.

In addition, doctors also prescribe medications that suppress the immune system and the GVHD reaction. These medications are taken starting on the day of the transplant and for the first few months following the transplant. All patients having an ALLO transplant will take these medications for a specified time, after which the medications will be gradually cut back and eventually stopped. During this time, small amounts of GVHD may appear and subside several times during the first year. Sometimes, it goes on longer, although it typically "burns itself out."

Chronic graft-versus-host disease

Chronic graft-versus-host disease (CGVHD), a long-lasting autoimmune illness, is a potential problem that can only affect those patients who have had an allogeneic (ALLO) transplant. It does not occur in all patients and has many degrees of severity and can be treated in different ways. Whether it occurs seems most related to whether there was GVHD in the first few months of the transplant process.

First appearing about three months after an ALLO transplant, CGVHD may be clinically "silent," producing no symptoms and requiring no specific therapy. Or, it may become a source of medical problems needing regular medical attention and treatment. Many different body parts can be affected to differing degrees.

CGVHD causes a set of very specific and distinctive symptoms.

• Tightening, stiffening and dryness of the skin
• Dryness, irritation and pain in the eyes
• Dry mouth, mouth sores, cavities
• Difficulty swallowing due to narrowing or contractures (known as strictures) in esophagus
• Weight loss (cachexia)
• Cough, difficulty breathing, lung infections

All of these symptoms can be treated, but CGHVD may persist despite therapy. Regular follow-up care with the transplant physician is strongly suggested, because treatment requires the ongoing use of immunosuppressive drugs, and the danger of infection remains high.

Other common side effects

In addition to infection and GVHD, other side effects may occur during a transplant, often related to destroying the original bone marrow or the treatments given. These include fatigue, mouth sores, sore throat, diarrhea, nausea and vomiting, low blood count, loss of hair, changes in skin pigmentation, and rash. These side effects can usually be managed through medication and do go away over time.

Almost any part of the body has the potential to be affected in some way by the transplant process. Most patients will only experience a few side effects. Furthermore, the same side effect that may be serious or troubling to one person may not occur in another person.

Doctors will monitor a patient's recovery using a variety of tests, including those for the liver, kidneys, lungs, heart, and other organs. The type, quantity, and severity of side effects will depend mainly on a patient's genetics, the amount and quantity of prior treatments (more prior treatments causes more side effects), and the type of transplant regimen received.

There is a risk of some permanent side effects. Infertility (the inability to have children) and cataracts (a clouding of the lens of the eye) are two possible permanent side effects from a bone marrow transplant. Patients are encouraged to discuss with their doctors the possible short-term and long-term effects they may experience prior to having a bone marrow transplant.

More Information

Managing Side Effects

Part I: Understanding Bone Marrow and Stem Cell Transplantation

Part II: Bone Marrow and Stem Cell Transplantation: Special types of transplantation

Part IV: Questions and Answers About Bone Marrow and Stem Cell Transplantation

Donating Bone Marrow

Additional Resources

Bone Marrow and Cord Blood Donation and Transplantation from the U.S. Department of Health and Human Services