Each person is a “one of a kind” collection of cells, tissues, and organs. Each person inherits a unique combination of genes from his or her parents. The body system that recognizes a person’s own cells from other cells and tissues is called the immune system. When the immune system finds “foreign” cells and tissues in the body, it attempts to destroy them to protect the body from harm. Bacteria and viruses are examples of foreign organisms that the immune system destroys. The immune system also removes the body’s own defective, damaged, or worn-out cells.
When a person receives a kidney transplant, the immune system sees it as foreign, and attempts to reject it by producing cells and/or antibodies that invade and damage the kidney. To prevent the immune system from damaging the transplanted kidney, you will take immunosuppressive (anti-rejection) drugs. It is very important to take your medications every day, exactly as prescribed. A sudden decline in kidney transplant function due to injury caused by the immune system can occur in spite of taking these medications. These events, called “rejections” or “rejection episodes” are discussed in the next section.
There are three types of rejection
- Hyperacute rejection is extremely rare today because it can almost always be prevented by tissue cross matching. Hyperacute rejection is caused by pre-formed antibodies directed against the donor kidney cells. It occurs within minutes to hours of transplantation and completely destroys the kidney transplant. If it occurs, the transplanted kidney must be immediately removed.
- Acute rejection can occur at any time, but it is most common from one week to three months after transplant surgery. Fifteen percent or less of patients who receive a deceased donor kidney transplant will have an episode of acute rejection. When treated early, it is reversible in most cases. The likelihood of rejection decreases as the kidney continues to function well.
- Chronic rejection happens over time and is due to scarring within the transplanted kidney. It may occur within months to years after your transplant. It is thought that controlling blood pressure, blood sugar, and cholesterol levels can help prevent chronic rejection. Because there usually are no symptoms, it is often diagnosed by changes in your laboratory tests and a kidney biopsy. To date, there is no medication used to reverse this type of rejection. Kidney function generally lasts for months or even years after the diagnosis is made. If the kidney transplant is rejected, you may be able to receive another transplant in the future. Sometimes the transplanted kidney must be surgically removed. Many patients choose a second transplant, which often functions well.
Signs and Symptoms of Acute Rejection
You may observe one, several, or all of the following during an episode of acute rejection:
- Tenderness or pain over the kidney transplant
- A general achy feeling
- Swelling in the hands and feet
- An elevated temperature
- A rapid weight gain
- An increase in blood pressure
- An increase in blood creatinine
- A decrease in urine output
The only way to diagnose acute rejection is to perform a renal biopsy. Under local anesthesia, a small fragment of your kidney is removed with a needle and examined under a microscope. A pathologist will determine whether rejection is present. There are several medications that can be used to reverse acute rejection, including intravenous steroids (Prednisone), antibodies, and other immunosuppressants.