Alzheimer's disease is a neurodegenerative disorder leading to progressive memory loss and dementia. It is characterized by an accumulation of so-called
amyloid plaques, protein aggregates that are deposited between the nerve cells of the brain, as well as clumps of disordered protein fibers, so-called tau braids inside the nerve cells.

For many decades, brain researchers believed that the accumulation of amyloid plaques and tau tangles was not only a sign of Alzheimer's disease, but also a direct trigger. Other factors, such as the neuroimmune system, have been overlooked. However, according to recent findings, astrocytes play an important role. According to new findings, astrocytes play an important role, because they coordinate the amyloid and tau relationships in the brain, the Pittsburgh team has now discovered. Normally, astrocytes support neuronal cells by supplying them with nutrients and oxygen and protecting them from pathogens.

For their study, the scientists examined blood samples from more than 1,000 cognitively unimpaired elderly people for evidence (biomarkers) of astrocyte reactivity and for the presence of pathological tau protein. The biomarker of interest is the - glial fibrillary acidic protein (GFAP).

The study found that only individuals whose findings were positive for amyloid as well as astrocyte reactivity showed signs of progressively developing tau pathology, suggesting a predisposition to clinical symptoms of Alzheimer's disease. Thus, the researchers can predict cognitive impairment through a blood test.

The findings have immediate implications for future clinical trials of Alzheimer's drug candidates.

Source and more information:
https://www.eurekalert.org/news-releases/990497