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Transplant rejection

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Contents of this page:

Illustrations

Antibodies
Antibodies

Alternative Names    Return to top

Graft rejection; Tissue/organ rejection

Definition    Return to top

Transplant rejection is when a transplant recipient's immune system attacks a transplanted organ or tissue. See also graft-versus-host disease.

Causes    Return to top

Your body's immune system protects you from potentially harmful substances, such as microorganisms, toxins, and cancer cells. These harmful substances have proteins called antigens on their surfaces. If your immune system identifies antigens that are foreign (not part of your body), it will attack them.

In the same way, foreign blood or tissue can trigger a blood transfusion reaction or transplant rejection. To help prevent this, tissue is "typed" before the transplant procedure to identify the antigens it contains.

Though tissue typing ensures that the organ or tissue is as similar as possible to the tissues of the recipient, the match is usually not perfect. No two people (except identical twins) have identical tissue antigens.

Immunosuppressive drugs are needed to prevent organ rejection. Otherwise, organ and tissue transplantation would almost always cause an immune response and result in destruction of the foreign tissue.

There are some exceptions, however. Corneal transplants are rarely rejected because corneas have no blood supply -- immune cells and antibodies do not reach the cornea to cause rejection. In addition, transplants from one identical twin to another are almost never rejected.

Symptoms    Return to top

The symptoms vary depending on the transplanted organ or tissue. For example, patients who reject a kidney may have less urine, and patients who reject a heart may have symptoms of heart failure.

Exams and Tests    Return to top

The doctor will feel the area over and around the transplanted organ, which may feel tender to you (particularly with transplanted kidneys).

There are often signs that the organ isn't functioning properly. For example:

A biopsy of the transplanted organ can confirm that it is being rejected. A routine biopsy is often performed to detect rejection early, before symptoms develop.

When organ rejection is suspected, one or more of the following tests may be performed prior to organ biopsy:

Treatment    Return to top

The goal of treatment is to make sure the transplanted organ or tissue functions properly, while at the same time suppressing the recipient's immune response. Suppressing the immune response can treat and prevent transplant rejection.

Many different drugs can be used to suppress the immune response. The dosage of the medication depends on the patient's status. The dose may be very high while the tissue is actually being rejected, and then reduced to a lower level to prevent it from happening again.

Outlook (Prognosis)    Return to top

Some organs and tissues are more successfully transplanted than others. If rejection begins, immunosuppressive drugs may stop the rejection. Then, you must take immunosuppressive drugs for the rest of your life.

However, immunosuppressive treatment is not always successful.

Possible Complications    Return to top

When to Contact a Medical Professional    Return to top

Call your health care provider if the transplanted organ or tissue does not seem to be working properly or if other symptoms occur. Also, call your health care provider if medication side effects develop.

Prevention    Return to top

ABO blood typing and HLA (tissue antigen) typing before transplantation helps to ensure a close match. Suppressing the immune system is usually necessary for the rest of the transplant recipient's life to prevent the tissue from being rejected in the future. Being careful to take post-transplant medications properly, and being closely monitored by your doctor may help prevent rejection.

Update Date: 2/15/2007

Updated by: Donald Accetta, MD, MPH, President, Allergy & Asthma Care, PC, Taunton, MA. Review provided by VeriMed Healthcare Network.

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