Risks of CAR T-Cell Therapy
- CAR T-cell therapy uses genetically modified immune cells to treat cancer
- A quarter or more of people who get this treatment have a reaction called cytokine release syndrome (CRS)
- CRS ranges from mild to severe
Chimeric antigen receptor, or CAR T-cell therapy, uses genetically altered T-cells — a type of immune cell — to hunt down and treat your cancer. Your doctor first removes T-cells from your blood, and then changes them in a lab to make them produce a special receptor on their surface called CD19. Once back in your body, the new receptors latch onto a specific protein on the cancer cells.
Read MoreCytokines and Their Effects
One unintended consequence of CAR T-cell therapy is that it triggers a flood of cytokines in the body. Cytokines are good for mobilizing your immune system against a foreign entity like cancer, but in large quantities, they can be harmful enough to make you very sick.When released into the body, cytokines can cause symptoms and reactions in various organs and systems. People can develop two different types of problems in response to cytokine release, Dr. Ganguly says. One is flu-like symptoms — including a fever, chills, fatigue, headache, and muscle aches.
The other is a more serious condition doctors call cytokine release syndrome (CRS). The term has been in the news a lot lately, because it’s also happened in people whose immune system has reacted to a COVID-19 infection.
The Stages of Cytokine Release Syndrome
CRS causes symptoms like a high fever, low oxygen levels, and low blood pressure. Doctors assign it a grade from 1 to 4 to indicate how serious it is, and what treatments they need to use against it.
Grade 1 is mild. Fever-reducers, antibiotics, anti-nausea drugs, and other treatments can manage symptoms until the person starts to feel better.
Grade 2 is when symptoms don’t improve, or they get worse, Dr. Ganguly says. The person’s blood pressure may drop, or they might have enough trouble breathing to require oxygen. At this stage doctors will give oxygen, fluids, and medicines to raise the blood pressure.
Grade 3 is a more severe reaction that involves problems with one or more organs. At this stage, the person will need to go to a hospital intensive care unit for treatment, which can include IV fluids, drugs that raise blood pressure, and oxygen.
Grade 4 is the most serious and life-threatening stage of CRS. People who reach this point can be sick enough to require a ventilator.
About one-quarter or more of people who go on CAR T-cell therapy will have some form of CRS. The good news is, very serious grade 4 reactions are rare. And few people actually die from CRS.
Watching for Side Effects
Researchers are studying methods to prevent CRS in people who have CAR T-cell therapy. Until those methods become available, vigilance is important. Your doctor will let you know what side effects to watch for after you have this treatment. Fever may be the first warning sign, and it’s something you need to call your doctor’s office about.
If you do develop CRS, your doctor will keep a close watch on you. You may need to go to the hospital and be monitored with regular checks of your blood pressure, oxygen level, and heart rate.
In very severe cases, doctors can give medicines called anti-cytokines — like interleukin-6 (IL-6) inhibitors and steroids — to slow the flood of cytokines and relieve symptoms. Anyone who has a severe case will need to stay in the hospital and be monitored very closely until they’re out of the woods.
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