While researchers found little evidence that the virus targets the brain directly, they discovered close network relationships between the virus and genes/proteins associated with several neurological diseases, most notably Alzheimer’s, pointing to pathways by which COVID-19 could lead to Alzheimer’s disease-like dementia. To explore this further, they investigated potential associations between COVID-19 and neuroinflammation and brain microvascular injury, which are both hallmarks of Alzheimer’s.
“We discovered that SARS-CoV-2 infection significantly altered Alzheimer’s markers implicated in brain inflammation and that certain viral entry factors are highly expressed in cells in the blood-brain barrier,” explained Dr. Cheng. “These findings indicate that the virus may impact several genes or pathways involved in neuroinflammation and brain microvascular injury, which could lead to Alzehimer’s disease-like cognitive impairment.”
The researchers also found that individuals with the allele APOE E4/E4, the greatest genetic risk factor for Alzheimer’s, had decreased expression of antiviral defense genes, which could make these patients more susceptible to COVID-19.
“Ultimately, we hope to have paved the way for research that leads to testable and measurable biomarkers that can identify patients at the highest risk for neurological complications with COVID-19,” said Dr. Cheng.