While CAR-T cell therapy has shown promise in treating cancer, it may also lead to side effects such as “brain fog,” which includes forgetfulness and difficulty concentrating, according to a new study.
CAR-T cell therapy is a form of immunotherapy in which a patient’s immune cells—T cells—are genetically engineered and infused back into the bloodstream to help recognize and destroy cancer cells more effectively.
The study, led by a team from Stanford University and published in the journal Cell, revealed that CAR-T cell therapy can cause mild cognitive impairments, independent of other cancer treatments.
Notably, the underlying mechanism appears to be the same as that seen in cognitive impairments caused by chemotherapy and respiratory infections such as influenza and COVID-19.
“CAR-T cell therapy is enormously promising. We are seeing long-term survivors after CAR-T cell treatment for aggressive cancers—patients who would otherwise not have survived,” said Michelle Monje, Professor of Pediatric Neuro-Oncology at Stanford Medicine.
“But we need to understand all its potential long-term effects, including this newly recognised syndrome of immunotherapy-related cognitive impairment, so we can develop treatments to address it,” Monje added.
In the study, researchers induced tumours in mice—in the brain, blood, skin, and bone—to examine how tumor location and the immune response triggered by CAR-T cells influenced cognition.
Standard cognitive tests, including object recognition and maze navigation, were used to evaluate the mice before and after treatment.
The findings showed that mild cognitive impairment occurred in mice with cancers located inside the brain, spreading to the brain, and even in those with tumors completely outside the brain. The only group that did not show cognitive issues were mice with bone cancer that caused minimal inflammation beyond the immune activity of the CAR-T cells.
The researchers identified the brain’s immune cells, called microglia, as central to this side effect.
Importantly, the study also proposed strategies to reverse these cognitive effects. The researchers said medications targeting brain fog could support better recovery for patients undergoing cancer immunotherapies.
—IANS