Amyloid plaque are a hallmark of Alzheimer's disease. Researchers, including one of Indian-origin, have discovered an immune system gene that can be associated with higher rates of amyloid plaque.
The research team found that a variant in the IL1RAP gene was associated with greater amyloid plaque accumulation over two years and had an even stronger effect than the well-known APOE e4 allele which is notorious for its association with the development of Alzheimer's disease.
The researchers used positron emission tomography imaging in nearly 500 individuals to assess the levels of brain amyloid deposits at an initial visit and again two years later. Following this, a genome-wide analysis was conducted to identify genetic variants associated with the rate of plaque accumulation during this two-year window.
The investigators found that APOE e4 was associated with higher rates of plaque buildup. However, they were surprised to find that IL1RAP showed an independent and even stronger influence on amyloid accumulation.
Researchers Vijay Ramanan, postdoctoral researcher at Indiana University School of Medicine, said, "This was an intriguing finding because IL1RAP is known to play a central role in the activity of microglia, the immune system cells that act as the brain's 'garbage disposal system' and the focus of heavy investigation in a variety of neurodegenerative diseases."
Andrew Saykin from Indiana University noted, "There is currently no therapy proven to halt or reverse the underlying cause of the progressive symptoms of dementia. These findings suggest that targeting the IL1RAP immune pathway may be a viable approach for promoting the clearance of amyloid deposits and fighting an important cause of progression in Alzheimer's disease." .
The findings were reported in the Brain.