Kidney rejection after transplant

Learn about kidney rejection after a transplant including why it may stop working and what can be done to treat the rejection.
Medically reviewed by
AKF's Medical Advisory Committee
Last updated
November 10, 2023

What is kidney rejection?

Rejection is your body's response to the transplanted kidney's foreign proteins. Rejection happens when your immune system, which protects your body from germs and foreign proteins, tries to fight your new kidney. Immunosuppressant medicines help keep your body from fighting your new kidney and rejecting it. This is why you take immunosuppressant medicines every day exactly the way your doctor has prescribed.

There are two types of kidney rejection that can happen after transplant:

  • Acute rejection usually happens soon in the months after a transplant. Out of 100 people who get a transplant, 5-20 people will have an acute rejection episode and less than five people will have an acute rejection episode that leads to complete failure of their new kidney.
  • Chronic rejection happens slowly over the years after a transplant. It means your new kidney may stop working over time because your body's immune system is constantly fighting it. Chronic rejection happens to kidney recipients more often than acute rejection.

What causes a kidney transplant to stop working?

There are many reasons why a kidney transplant could fail, such as:

  • Rejection can damage your kidney and lower the number of years it works.
  • Infection can cause permanent problems with the kidney if it is not found and treated early.
  • Long-term side effects of medicines that can be harmful to kidneys.
  • Not taking immunosuppressant medicines or following other treatments prescribed by your doctor. Without enough immunosuppressant medicine in your blood, your body's immune system will attack and damage the kidney. 

How will I know if my body is rejecting the transplanted kidney?

Many people have no signs or symptoms of kidney rejection. Every person is different. Signs and symptoms of kidney rejection may include:

  • Feeling like you have the flu, such as body aches, chills, headache and feeling sick to your stomach
  • Fever of 101° F or higher
  • Urinating (peeing) less than usual
  • Having very high blood pressure
  • Suddenly gaining weight
  • Swelling in your ankles
  • Pain or tenderness in your side or belly area
  • Feeling very tired

If you have any of these signs or symptoms, call your doctor right away.

To know if you are having kidney rejection, your doctor may do these tests:

  • Blood tests, such as creatinine and blood urea nitrogen (BUN), which measure how well your kidneys filter waste from your blood. They may also do blood tests that show how likely it is you will have rejection.
  • Kidney ultrasound, which is a safe and painless test that uses sound waves to make images of your kidneys
  • Kidney biopsy, which means taking a small sample of kidney tissue and looking at it under a microscope

How is kidney rejection treated?

If your doctor tells you that you are having kidney rejection, it does not mean that your new kidney will fail. It could mean that your doctor may just need to adjust your medicines to keep your body from rejecting your kidney.

The usual treatment for kidney rejection is to change the amount of immunosuppressant medicine to a higher dose. Treatment depends on the severity of the rejection. Your doctor may have you stay in the hospital for 3-5 days for treatment.

What happens if my body rejects the new kidney and it fails?

If your new kidney fails, you will need to go back on dialysis to live. You can also get evaluated for another kidney transplant. If you are healthy enough, you can have more than one kidney transplant.

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