COVID-19 Linked With Alzheimer's Disease-Like Dementia

Individuals with the allele APOE E4/E4 were found to be more susceptible.

A recent study conducted by investigators from the Cleveland Clinic has discovered an overlap between an infection with COVID-19 and brain changes that are commonly seen in individuals with Alzheimer’s disease.

Results from the study were published in the journal Alzheimer's Research & Therapy.

"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," Feixiong Cheng, lead author on the study said. "These findings indicate that the virus may impact several genes or pathways involved in neuroinflammation and brain microvascular injury, which could lead to Alzheimer’s disease-like cognitive impairment."

For the study, the team of investigators analyzed datasets of patients with both COVID-19 and Alzheimer’s disease. Using artificial intelligence, they measured the distance between SARS-CoV-2 host genes and those associated with different neurological diseases where closer proximity suggests related or shared disease pathways.

The team also looked at genetic factors which allow the SARS-CoV-2 virus to infect brain cells and tissue.

Findings from the study showed that there was a close network relationship between SARS-CoV-2 and genes/proteins that are associated with some neurological disease such as Alzheimer’s. This could lead to COVID-19 causing Alzheimer's-like dementia.

Additional findings showed that those with the allele APOE E4/E4, had a decreased expression of antiviral defense genes, which could explain why some people are more susceptible.

"While some studies suggest that SARS-CoV-2 infects brain cells directly, others found no evidence of the virus in the brain," Cheng said. "Identifying how COVID-19 and neurological problems are linked will be critical for developing effective preventive and therapeutic strategies to address the surge in neurocognitive impairments that we expect to see in the near future."