Health Encyclopedia

Transplant rejection

Definition

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

Alternative Names

Graft rejection; Tissue/organ rejection

Causes, incidence, and risk factors

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

The organ does not function properly
General discomfort, uneasiness, or ill feeling
Pain or swelling in the location of the organ (rare)
Fever (rare)

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.

Signs and tests

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:

Less urine output with kidney transplants
Yellow skin color and easy bleeding with liver transplants
Shortness of breath and less tolerance to exertion with heart transplants

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:

Lab tests of kidney or liver function
Kidney ultrasound
Kidney arteriography
Abdominal CT scan
Heart echocardiography
Chest x-ray

Treatment

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.

Expectations (prognosis)

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.

Complications

Loss of function of the transplanted organ/tissue
Infections (because the person's immune system is constantly suppressed)
Side effects of medications, which may be severe

Calling your health care provider

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

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.

Review Date:2/15/2007
Reviewed By:Donald Accetta, MD, MPH, President, Allergy & Asthma Care, PC, Taunton, MA. Review provided by VeriMed Healthcare Network.

ADAM Quality A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.