Cytokine release syndrome, or CRS

What is CRS?

CRS is a serious and life-threatening side effect caused by a large and quick release of cytokines (a type of protein) into the blood. CRS can sometimes be severe or cause death. Always let your healthcare team know how you are feeling so they can treat this and other side effects.

When can it happen?

CRS can happen anytime after the infusion. However, the exact timing of when it can happen varies between CAR T cell therapies. Your healthcare team would monitor you throughout this time, but it’s important to track your symptoms regularly.

What are the symptoms?

Symptoms may include:

  • Fever (100.4ºF/38ºC or higher)
  • Chills/shaking chills
  • Fast or irregular heartbeat
  • Drop in blood pressure—lightheadedness or dizziness
  • Shortness of breath
  • Headache
  • Nausea
  • Fatigue
  • Confusion
  • Swelling
  • Stomach pain

  • Call your doctor or get emergency help right away if you experience any of these or other symptoms.
  • Symptom tracking and side effect monitoring can be found in our Resources.

These are not all the possible signs and symptoms of CRS. Please talk to your doctor or healthcare provider about any questions that you may have.