Patients with Multiple Sclerosis Less Likely to Develop Alzheimer Disease
Multiple sclerosis (MS) is associated with a reduced risk of Alzheimer disease pathology, according to a study published in Annals of Neurology.
“Our findings imply that some component of the biology of multiple sclerosis, or the genetics of MS patients, is protective against Alzheimer’s disease,” said study first author Matthew Brier, MD, PhD, an assistant professor of neurology and of radiology at the Washington University School of Medicine, St. Louis, Missouri. “If we could identify what aspect is protective and apply it in a controlled way, that could inform therapeutic strategies for Alzheimer’s disease.”
The investigation was prompted by a long-held observation of Dr Brier’s mentor and collaborator, Anne Cross, MD, also of the Washington University Department of Neurology.
“I noticed that I couldn’t find a single MS patient of mine who had typical Alzheimer’s disease,” Dr Cross recalled. “If they had cognitive problems, I would send them to the memory and aging specialists here at WashU Medicine for an Alzheimer’s assessment, and those doctors would always come back and tell me, ‘No, this is not due to Alzheimer’s disease.’”
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To investigate further, researchers used a blood test recently approved by the US Food and Drug Administration that is designed to predict the presence of amyloid plaques in the brain, an indicator of Alzheimer disease. The study included 100 patients with MS and 300 control subjects without MS matched for age, sex, genetic risk for Alzheimer disease, and cognitive decline. Additionally, 11 participants with MS also underwent positron emission tomography.
Patients with MS, the study found, had about half the rate of amyloid pathology compared with matched control subjects.
Among patients with MS, amyloid plaque accumulation in the brain was less likely in those with a typical MS history in terms of age of onset, severity, and overall disease progression than in those with atypical presentations, according to the study.
“Perhaps when the Alzheimer’s disease amyloid pathology was developing, the patients with MS had some degree of inflammation in their brains that was spurred by their immune responses,” Dr Brier speculated.
Dr Brier and Dr Cross have begun further research to better understand the human genetics involved in the apparent protective effect of MS itself against Alzheimer disease.
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