Kidney Transplantation
For people of all ages whose kidneys do not function despite other treatments (irreversible kidney failure), kidney transplantation is a lifesaving alternative to dialysis. In the United States, about 11,000 kidneys are transplanted each year. About 90% of kidneys obtained from living donors are functioning 1 year after transplantation; 3 to 5% of these kidneys stop functioning during each year that follows. About 70 to 90% of kidneys from someone who has just died are functioning after 1 year; 5 to 8% stop functioning during each year that follows. Transplanted kidneys sometimes function for more than 30 years. People with successful kidney transplants can usually lead normal, active lives.
More than two thirds of transplanted kidneys come from people who have died, usually in an accident. The kidneys are removed, cooled, and transported quickly to a medical center for transplantation to a person who has a compatible tissue type and whose blood does not contain antibodies to the tissues of the donor.
Kidney transplantation is a major operation. The donated kidney is placed in the pelvis through an incision and is attached to the recipient's blood vessels and bladder. Usually, the nonfunctioning kidneys are left in place. Occasionally, they are removed because they are causing uncontrollable high blood pressure or are infected.
Despite the use of immunosuppressants, one or more episodes of rejection often occur shortly after transplantation. Rejection of a kidney may cause fever as well as weight gain due to fluid retention (because the kidneys are not removing enough fluids from the bloodstream). The area over the transplanted kidney may be tender and swollen, less urine may be produced, and blood pressure may increase. Blood tests can detect deteriorating kidney function. If doctors are not sure whether the kidney is being rejected, they can perform a biopsy using a needle.
Rejection can usually be stopped by increasing the dose of the immunosuppressant, changing the type, or using more than one immunosuppressant. If rejection cannot be stopped, the transplantation is unsuccessful. The rejected kidney may be left in place unless fever, tenderness, blood in the urine, or high blood pressure persists. When transplantation is unsuccessful, dialysis must be started again. Often, another kidney can be transplanted after the person has recovered from the first attempt. The chance of success with second transplants is almost as good as that with first transplants.
Rejection and other complications usually occur within 3 to 4 months of transplantation. After that, the recipient continues to take immunosuppressants indefinitely, unless they cause side effects or a severe infection develops. If immunosuppressants are discontinued even briefly, the body could reject the new kidney. Rejection that develops over many weeks or months is relatively common and may cause kidney function to gradually deteriorate.
Compared with the general population, kidney transplant recipients are 10 to 15 times more likely to develop cancer, probably because the drugs needed to prevent rejection of the transplanted kidney also suppress the immune system, which helps defend the body against cancer. Kidney transplant recipients are about 30 times more likely to develop cancer of the lymphatic system (lymphoma) than the general population. However, even among kidney transplant recipients, this cancer is still relatively uncommon.
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