Side effect of popular Alzheimer's treatment may actually be a good sign, new PET findings suggest
New research out of Houston Methodist suggests that certain Alzheimer’s treatment-related side effects may actually be a positive sign.
Amyloid-related imaging abnormality edema (ARIA-E) is a known side effect of anti-amyloid monoclonal antibody treatments, such as lecanemab (Leqembi) and donanemab (Kisunla). These treatments essentially scrub the brain of amyloid plaques, which in turn reduces the severity of cognitive decline associated with AD. Though the condition typically resolves on its own, in rare cases the side effects associated with the drugs, such as seizures, coma and brain hemorrhage, can be deadly. As such, routine brain imaging is recommended for patients to monitor for signs of ARIA-E.
New research, however, suggests the finding may indicate that certain parts of the brain are more responsive to treatment.
“This study shows that not all parts of the brain respond equally to anti‑amyloid therapy,” noted Joseph Masdeu, MD, PhD, professor of Neurology at Houston Methodist Research Institute. “For the first time, results show that the brain regions that swell during treatment have a greater decrease in the amyloid signal on positron emission tomography scan, possibly because more amyloid is removed or because amyloid is hidden on PET. That reframes ARIA‑E from being only a side effect to a possible sign of strong local treatment activity.”
For their work, the researchers analyzed the cases of a handful of patients with ARIA-E. Using PET scans, the team quantified changes in Aβ PET signal before and after ARIA-E resolution, comparing regions affected by ARIA-E with unaffected regions.
Through this, they determined that areas of the brain that swelled the most tended to show the greatest reduction of plaques after the swelling resolved. This suggests certain areas might be more responsive to treatment than others and also raises new questions about whether ARIA-E should be perceived as a negative side effect or a positive benefit.
More research is needed to validate the findings, as the study sample size was quite small. The team plans to expand on their work by working with additional institutions, including the Longitudinal Early Onset Alzheimer’s Disease Study (LEADS) consortium.
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In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.