Encephalitis: A Potentially Severe Complication of Immunotherapy

According to a story from EurekAlert!, in recent years immunotherapy, which are methods of treatment that enhance or harness the body’s immune system to fight disease, have become increasingly prominent and important parts of treatment for cancer. However, a recent case has come to light of a cancer patient that died from severe encephalitis (brain inflammation) after 18 months of treatment with immunotherapy. The incident prompted a team of researchers from the Vanderbilt-Ingram Cancer Center to dig deeper. Their findings revealed that encephalitis is a rare complication that can appear in some patients that use a class of immunotherapy drugs called checkpoint inhibitors. 

About Encephalitis

Encephalitis is a rare condition in which the brain become inflamed. The severity of the condition can vary substantially. Viral infection is the most common cause of encephalitis, but it can also be triggered by bacterial infections, certain medications, and can even be autoimmune. In children, symptoms include reduced appetite, irritable behavior, and fever. Adults also experience fever as well as confusion, seizures, and headaches. More severe complications such as hearing loss, memory loss, and trouble speaking may also appear. Severe cases may last for several months. Treatment of encephalitis depends on the cause; when viruses or bacteria are responsible, antiviral or antibiotic drugs are standard. Steroids, acetaminophen, and sedatives may also be used. Physical and occupational therapy may be necessary if the brain is affected following the disease event. To learn more about encephalitis, click here

About The Research

Analysis of the patient’s tissue revealed the presence of T-cells primed to target the Epstein-Barr virus. The scientists also noted the prevalence of other T-cells that closely resembled the T-cells meant to destroy Epstein-Barr virus. A data review from a pool of 2.501 patients revealed a total of 22 cases of meningoencephalitis (a type of encephalitis) in patients that had been treated with immune checkpoint inhibitors. Unfortunately, the researchers had no way of knowing if the Epstein-Barr virus could have been involved.

The findings are just the latest in a slew of research that had revealed the potential for rare but serious side effects from the use of immune checkpoint inhibitors. Other findings have revealed vasculitis, colitis, hepatitis, and myocarditis as other examples of severe complications that can occur very rarely with the use of these drugs. Regardless, these complications can usually be controlled with steroids, and typically the benefit of using immune checkpoint inhibitors outweighs the risks.