Cytokine Release Syndrome

What is a cytokine?

A cytokine is a small protein that lets your body know when an immune response is needed. They play an important part in communication between cells when your body may be stressed due to inflammation, infection, or trauma.

What is cytokine release syndrome?

Cytokine release syndrome (CRS) is an inflammatory reaction that affects your whole body (systemic). It can be caused by certain medications, immunotherapy treatments (CAR-T cells), infections, or illnesses. It is a release of cytokines into your blood from your immune cells. This is a large and quick release that can happen after treatment with some types of immunotherapies, like monoclonal antibodies and CAR-T cells. This release can overwhelm your body making it hard for your body to adjust.

What are the symptoms of cytokine release syndrome?

Symptoms can range from mild to severe. The mild symptoms are:

• Fever.
• Fatigue.
• Nausea.
• Headache.
• Rash.
• Generalized aches and pain.

More severe symptoms are:

• Fast heartbeat.
• Low blood pressure.
• Trouble breathing.
• Confusion, dizziness, headache, and seizures.
• Organ failure.
• Higher than normal liver and kidney levels in your blood.
• Changes in blood clotting.

The symptoms of cytokine release syndrome are the same as other health issues, like neutropenic fever and sepsis. It is important for your care team to rule out other illnesses that are not cytokine release syndrome.

How is cytokine release syndrome managed?

If you are having any symptoms of cytokine release syndrome related to your immunotherapy treatment, you should be closely monitored. You will have your vital signs checked and blood tested more often by your healthcare provider. Your symptoms will be managed as needed. Examples of treatments to manage symptoms include:

• IV (intravenous, into a vein) fluids.
• Oxygen.
• Medication to manage your blood pressure, heart function, pain, and prevent seizures.
• Blood products.

You may be given medications to lower your immune response, like corticosteroids, tocilizumab, and siltuximab. These medications are immunosuppressive. This means they could interfere with the immunotherapy treatment you received. Your care team will decide the best treatment for you before giving you these medications. If your reaction is severe, you may need to be treated in an intensive care unit (ICU) with a breathing tube or machines that help your heart work.

If you think you have CRS, contact your provider right away.