Neurodegenerative disease: Two blood molecules may predict Alzheimer’s disease development

The levels of two molecules in blood, tau phosphorylated at threonine-181 (P-tau181) and neurofilament light (NfL), may predict future cognitive decline and progression to Alzheimer’s disease dementia in individuals with mild cognitive impairments, according to a paper published in Nature Aging. These findings could aid the development of routine blood tests to track Alzheimer’s disease progression in at-risk populations.

Around 50 million people around the world live with Alzheimer’s disease, and it accounts for 50–70% of dementia cases. Alzheimer’s disease is characterized by the accumulation of proteins in the brain that are thought to cause neuronal death, eventually leading to dementia. Recent research indicates that these proteins are found in blood and that tests based on their plasma concentrations can be used to diagnose the disease or distinguish it from other common forms of dementia.

Oskar Hansson and colleagues developed and validated models of individualized risk prediction of cognitive decline and transition to Alzheimer’s disease dementia using data from 573 patients with minor cognitive impairments from two independent cohorts. The authors compared the accuracy of several models based on various combinations of blood biomarkers to predict cognitive decline and dementia over four years. They found that the best predictive model was based on a form of tau called P-tau181, and NfL, a protein that reflects the presence of neuronal death and injury.

The authors conclude that their findings demonstrate the value of using specific combinations of blood-based biomarkers to make individualized predictions about the progression of Alzheimer’s disease. However, further research with larger cohorts is needed.