The Immune System May Play a Role in Alzheimer’s Development, Study Says

A new study from Brigham and Women’s Hospital suggests that there may be a link between the immune system and the onset of Alzheimer’s disease.

The hospital’s research, published in Nature Neuroscience, looked at the genetic variants in proteins typically associated with Alzheimer’s—specifically the levels of these proteins located in monocytes, the immune cells that travel to the brain and central nervous system. After analyzing blood samples from 100 young patients and 61 older patients, the team discovered that high levels of the protein TREM2—which is now a primary target of Alzheimer’s medications—may be associated with increased risk for the disease.

TREM2 has been the subject of past Alzheimer’s studies, but it has previously been unclear whether excessive or deficient levels of the protein were related to Alzheimer’s development.

In a statement, co-corresponding author Philip De Jager said the results are among the first findings to suggest that immune cells may not only change as a result of Alzheimer’s, but could be an underlying cause of the condition.

“Before genetic studies, many thought that inflammation was a symptom of or a reaction to the disease,” De Jager said in the statement. “But our study and others build a compelling case that the immune system may be involved in the development of Alzheimer’s disease.”

In light of the study, the announcement says, the team will begin measuring levels of TREM2 in patients to continue studying its diagnostic implications on Alzheimer’s.