Kidney Transplant Rejection

After an organ transplant, there’s a risk of rejection. Kidney transplant rejection is when your body doesn’t accept the new kidney and fights against it (rejects it). You can help healthcare providers treat rejection before long-lasting damage occurs by learning the early symptoms of kidney rejection.


Rejection and Signs of Rejection for Your New Kidney

What is a kidney transplant rejection?

A rejection is your immune system’s way of protecting your body from your new kidney, which it perceives as a threat because it’s not your own. Even when your kidney donor is a good match, your body essentially recognizes the kidney as being “new” and reacts by trying to destroy it. The immune system reacting to a kidney that’s been transplanted into your body is called rejection.

Although kidney rejection is most common in the first six months after transplant surgery, it can occur years later. While your risk of transplant rejection goes down over time, it never goes away completely.

Medications called immunosuppressants help to prevent and treat a kidney transplant rejection by blocking your immune system from damaging your kidney. People who receive a kidney transplant take immunosuppressants. If rejection occurs, your healthcare provider prescribes a higher dose or a different combination of immunosuppressant drugs.

Your healthcare provider can usually recognize and treat a kidney rejection before it causes any major or irreversible damage. It’s very important for you to take your medications exactly as prescribed, obtain laboratory tests and attend all follow-up appointments with your provider after a kidney transplant.

Types of kidney transplant rejection

There are two main types of kidney transplant rejection: acute and chronic. The main difference is when the rejection occurs.

Acute rejection

Acute rejection happens within the first 12 months of a transplant. It’s more likely to occur within the first several weeks. Acute means it happens quickly. If you don’t have an acute rejection episode after 12 months, you may be less likely to have one as long as you take your medication as prescribed. Your healthcare provider will adjust your medications if they diagnose acute rejection in hopes of preventing your body from damaging your kidney.

Chronic rejection

Chronic rejection typically happens slowly and over several years. Your body’s immune system slowly and constantly fights your new kidney, which leads to kidney damage. Chronic rejection happens to kidney recipients more often than acute rejection. It can happen years after a kidney transplant. The signs can often be subtle and unnoticeable because the rejection is gradual.

You can also have a cellular rejection which means T lymphocytes, a specific type of white blood cell, cause the rejection. Your immune system can also reject the new kidney through antibodies. This is called an antibody-mediated rejection.


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How common is kidney transplant rejection?

Some degree of rejection is very common. About 15% to 20% of people who receive a new kidney will experience some type of rejection. The severity of the rejection varies.

Symptoms and Causes

What are signs of kidney rejection after transplant?

If you receive a kidney transplant, you should be aware of the signs of organ rejection and let your healthcare provider know if you experience any of them. Many of these signs are nonspecific and can be caused by problems that aren’t rejection. If you think you’re experiencing any of these symptoms, contact your transplant team immediately:

  • Fever higher than 101 degrees Fahrenheit (38 degrees Celsius).
  • Flu-like symptoms like chills, body aches, headache or nausea.
  • New pain or tenderness around your kidney area (the transplant site).
  • Sudden weight gain greater than 2 to 4 pounds within a 24-hour period.
  • Peeing less often.
  • Swelling in your ankles.
  • Feeling tired or having no energy.

Some people may not have any noticeable symptoms. This is why it’s critical to attend any follow-up appointments and to get scheduled blood tests. Your healthcare provider will perform periodic blood tests to check your kidney function. It’s often in these tests that they can detect a kidney rejection.


What is the most common cause of kidney transplant rejection?

The most common cause of a kidney transplant rejection is not taking your immunosuppressant (also called anti-rejection) medication. Healthcare providers prescribe antirejection drugs to all kidney transplant recipients. Not taking them regularly or as prescribed can result in not having enough medication in your blood. The medication works by stopping your immune system from hurting your new kidney. Without the medication, your body’s immune system attacks and damages your new kidney.

A kidney transplant rejection can also be triggered by certain infections or other health events that trigger your immune system.

Diagnosis and Tests

How do you know if your kidney is rejecting?

Your healthcare provider performs periodic follow-up appointments to help detect any signs of kidney rejection. At these appointments, your provider may perform one or all of the following:

  • Blood tests: Your provider may order a complete blood count (CBC) to evaluate white blood cell, red blood cell and platelet counts. Blood tests such as creatinine and blood urea nitrogen (BUN) look specifically at your kidney function. There are special tests that your provider can order to understand if your immune system has made antibodies to the kidney, called donor-specific antibody tests.
  • Kidney biopsy: A biopsy involves your provider taking a sample of kidney tissue and looking at it under a microscope.

Management and Treatment

Can you stop a transplanted kidney from rejecting?

Members of your healthcare team do all they can to prevent you from rejecting your new kidney. But, sometimes, it happens despite everyone’s best efforts. Once your immune system begins to reject your kidney, your provider will adjust your medications to try to stop the rejection from progressing. Just because you experience kidney rejection doesn’t mean your kidney will fail. Most of the time, your provider can treat a rejection and the kidney will continue to function.

To reduce your risk of kidney rejection:

  • Attend all your follow-up appointments.
  • Take your immunosuppressant medications exactly as your provider prescribes.
  • Alert your provider if you notice any signs of kidney transplant rejection.
  • Eat a healthy diet. Talk to your provider about what foods you should eat more of and which you should limit.
  • Manage any other health conditions you have, like diabetes or high blood pressure.
  • Wash your hands often and limit interactions with people who’ve been sick.

How is a kidney rejection treated?

If your healthcare provider determines that a kidney rejection is occurring, they’ll adjust your prescription for immunosuppressant medication to prevent further complications. You may require additional medications or treatments for a short time, specifically for a rejection. Some people receive treatment for a rejection in a hospital for as long as five days. Others can receive treatment in an outpatient setting.

Since immunosuppressants, or antirejection medications, work by lowering (suppressing) your immune system to weaken how hard it can fight, treatment for a kidney rejection typically involves increasing the dosage of immunosuppressants. Keep in mind that since anti-rejection medicines weaken your immune system, you may be more susceptible to infection. Your healthcare provider will manage and monitor your medication carefully as immunosuppressants are powerful drugs with their own set of risks.

A note from Cleveland Clinic

The word “rejection” isn’t something you want to hear after a kidney transplant. The good news is that a kidney rejection is usually treatable with the right medication. Kidney rejection doesn’t mean your kidney will fail. Because rejection can happen years after a transplant, it’s a good idea to recognize the signs of kidney rejection so you can let your healthcare provider know. You should also keep up with regular checkups and take your medication as prescribed.

Medically Reviewed

Last reviewed by a Cleveland Clinic medical professional on 08/14/2023.

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