The Immune System and Organ Transplant: What You Should Know
Thousands of people undergo organ transplant surgery each year and get a second chance to lead healthy lives. While there are risks involved in any surgery, those who undergo an organ transplant also face the possibility that their immune system will reject their new organ. Fortunately, medical research has come a long way and now offers those in need of a new organ an even greater chance of successful recovery.
How the Immune System Works
The immune system is a complex biological system in the human body. It is made up of cells, tissues, and organs that work constantly to keep out foreign materials that may be harmful, such as viruses, bacteria, fungus, and parasites. These harmful materials are also known as antigens.
The main defenders in the immune system are lymphocytes, more commonly known as white blood cells. They are made in the bone marrow and develop into either T cells or B cells. These two types of cells travel through the bloodstream where they recognize and attack any harmful antigens that may be present.
Another important part of the immune system is its ability to recognize (and later remember) the difference between cells that belong in the body and those that do not, such as tumor and viral-infected cells.
The immune system is able to recognize the difference between cells that belong and those that do not by learning to identify markers that are found on cell surfaces. In people, the markers are referred to as the human leukocyte antigen (HLA), and are proteins of the immune system.
The Immune System and Organ Transplant
Some people may have diseases that lead to organ failure, or they may have suffered an injury that would require an organ transplant. Major organs that may be transplanted include:
While many organ transplants are successful, there is still a chance that the recipient's immune system will reject the transplanted organ. Before a patient can have an organ transplant, they will take a blood test that will allow doctors to perform tissue typing. This lets doctors check the compatibility between donor and recipient tissues by comparing HLA markers.
Because everyone’s HLA markers are different, with the exception of identical twins, matches must be as close as possible. Without a close match, the organ will be rejected, and T cells will begin their attack. There are three types of organ rejection:
- Hyperacute rejection—can occur within minutes of a transplant
- Acute rejection—can occur a few weeks after a transplant
- Chronic rejection—can occur months after a transplant
What to Expect After an Organ Transplant
Regardless of how well-matched a donor and recipient are, the recipient’s body will still try to reject the new organ since it is made completely of foreign cells. Fortunately, there are ways for patients and doctors to work together to prevent rejection or infection. While treatments and healthcare will vary depending on the organ transplanted and the patient, most recovery programs will involve similar care.
Healthcare After Organ Transplant Surgery
After an organ transplant, patients will continue to work with their healthcare providers who will monitor their recovery. They will also work together to develop medication dosage and lifestyle plans that will keep patients healthy for the rest of their lives.
To prevent rejection, immunosuppressant drugs will be given to decrease the body’s normal immune response. These drugs will need to be taken for the rest of the patient’s life. Drugs may include]]> tacrolimus]]> (Prograf, Protopic), mycophenolic acid (Myfortic), ]]>sirolimus]]> (Rapamune), ]]>prednisone]]>, ]]>cyclosporine]]> (Neoral, Sandimmune, Gengraf), mycophenolate mofetil (CellCept), and ]]>azathioprine]]> (Imuran, Azasan).
Since these drugs reduce the immune system’s ability to fight other types of infections, a combination of antiviral, antifungal, and antibiotic medications may also be prescribed.
There is also an increased risk of cancer as a result of suppressing the immune system. However, the risk of cancer may vary depending on different factors, such as age or whether there is a family history of cancer.
After an organ transplant, patients will also continue to undergo many tests to ensure that there is no infection and that the organ is not being rejected. Tests vary depending on the specific organ, but can include blood tests, ]]>X-rays]]>, or ]]>biopsies]]>.
Diet and Exercise
While each patient’s circumstances and recovery time will be different, discussing a diet and exercise program with healthcare providers may be a wise decision. Patients should learn about creating a balanced diet for themselves, which may also help with other side effects of transplant surgery and medications, such as high cholesterol.
Exercise, which may be very minimal to start, is also recommended to help the body return to a healthy state and may also help with weight gain caused by taking immunosuppressant drugs.
Additional Health Concerns
Some women worry about becoming pregnant after an organ transplant. While there are risks involved, particularly during the first year after surgery when the risk of rejection is highest, many women have successfully had children after their transplant. Any plans to get pregnant should be discussed with healthcare providers.
Those who plan to receive organ transplants are required to stop smoking or using other drugs or alcohol in order to stay on the waiting list for an organ transplant. After surgery, some may find it hard to avoid old habits. Therefore, it is important for these individuals to find a support system, whether it’s family or a support group, to ensure that they stay healthy.
With proper care, the body will have a better chance of accepting the new organ, as well as avoiding possible infections after the transplant.
National Institutes of Health
The United Network for Organ Sharing
Canadian Association of Transplantation
The Organ Donation and Transplant Association of Canada
Fishman JA. Infection in solid organ transplant recipients. N Engl J Med. 2007;357(25):2601-2614.
Kindt TJ, Goldsby RA, Osborne BA, Kuby J. Kuby immunology. 6th ed. New York: W.H. Freeman; 2007.
Mayo Clinic. Organ transplant drug therapy. Mayo Clinic website. Available at:
http://www.mayoclinic.org/specialty-pharmacy/organ-transplants.html. Accessed August 24, 2009.
Pace B. Suppressing the immune system for organ transplants. JAMA. 2000;283(18):2484.
Last reviewed September 2009 by ]]>Zarina G. Memon, MD]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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