High immune cell ratios may predict future Alzheimer's disease risk

Circulating white blood cells called neutrophils are some of the immune system's first responders. Their numbers shoot up during infection and inflammation, shifting the ratio of neutrophils to other types of immune cells in the blood.

This ratio, called the neutrophil to lymphocyte ratio (NLR), is easily obtained from a complete blood cell count, which is used by clinicians to diagnose infection and other immune conditions.

Now, a new study led by researchers at NYU Langone Health shows that a high NLR could identify patients at risk of developing Alzheimer's disease and related dementias before they exhibit any signs of cognitive impairment. The researchers analyzed NLR data from nearly 400,000 patients from two health care systems.

Our study is the first large-scale investigation showing that neutrophil metrics are associated with increased risk of dementia in humans. 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."