Researchers have found that a blood marker linked to inflammation may reveal Alzheimer’s risk years in advance. This discovery could allow for a simple blood test to spot at-risk folks years before they have any symptoms.
Scientists from NYU Langone Health found that higher neutrophil levels were linked to a higher chance of developing dementia. Neutrophils are a kind of white blood cell that act as part of the immune system as first line defense against infection and inflammation. Their numbers rise rapidly when the immune system is activated. They can be measured with a standard blood test that is often used to find infections and check immune health. The test is called the neutrophil to lymphocyte ratio (NLR). The research suggests the measurement doesn’t just reflect current health but also IDs people at high risk for Alzheimer’s and other forms of related dementia.
"Our study is the first large-scale investigation showing that neutrophil metrics are associated with increased risk of dementia in humans," said study first author Dr. Tianshe He, of NYU Grossman School of Medicine. "Neutrophil elevation is happening before any evidence of cognitive decline, which makes a compelling case for studying whether neutrophils are actively contributing to disease progression."
Having a high NLR alone is unlikely to be a clear indicator that someone will develop Alzheimer’s. But when a person has other risk factors, it could be a sign that the person should be watched more closely for early intervention.
Neutrophils are needed to fight infections. But they can also cause damage as they can drive inflammation that can harm blood vessels and brain tissue. Evidence of neutrophil-driven inflammation has been found in the brains of people with Alzheimer’s. The white blood cells may speed the disease’s progression.
Additionally, as we age, our bodies have a harder time cleaning out old neutrophils. That can lead to increased inflammation and tissue damage. Cause-and-effect has not been confirmed about how neutrophils impact brain health.
Mount Sinai is also working on blood tests to detect Alzheimer’s sooner. Their research looks at mitochondria to see early cellular damage.
“A blood biomarker could eventually support earlier interventions — for example, lifestyle changes that include modifications to exercise and diet and reducing inflammation. Earlier interventions align with what we know about the efficacy of newer Alzheimer’s drugs, which work best when started in the earliest stages,” said first author Dr. Diddier Prada.
