CLEVELAND — There is certainly no shortage of reporting about the toll that SARS-CoV-2, the virus that causes COVID-19, can take on the lungs. But its impact on the mind can also be devastating for patients too, a new study shows. Researchers say there is an overlap between COVID-19 and brain changes often seen in Alzheimer’s patients.
The emerging connection between COVID-19 infection and subsequent neurological issues is equal parts concerning and mystifying. SARS-CoV-2 has proven to be entirely unpredictable over the course of the pandemic. Still, its troubling impact on the cognition of so many recovered patients feels entirely out of place for a virus mainly associated with respiratory symptoms. Now, a new report put together by scientists at the Cleveland Clinic is offering some answers.
Study authors conclude there is little to no evidence supporting the theory that COVID-19 directly targets and attacks the brain. However, close relationships were noted between COVID and a number of genes and proteins long linked to several neurological diseases, including Alzheimer’s. All in all, these findings suggest that there are indeed pathways by which COVID-19 “could lead to Alzheimer’s disease-like dementia.”
Additionally, researchers searched for any potential associations linking COVID to either neuro-inflammation or brain microvascular injuries. Both of those conditions are considered warning signs for developing Alzheimer’s.
“While some studies suggest that SARS-CoV-2 infects brain cells directly, others found no evidence of the virus in the brain,” says lead study author Feixiong Cheng, Ph.D., assistant staff in Cleveland Clinic’s Genomic Medicine Institute, in a media release. “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.
“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,” he continues. “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.”
Study could help doctors identify which COVID patients are at risk for Alzheimer’s symptoms
The latest artificial intelligence technology was used to analyze a number of pre-existing datasets of both COVID-19 patients and Alzheimer’s patients. More specifically, researchers looked to measure the proximity between SARS-CoV-2 host genes/proteins and other genes linked to various neurological diseases. Why? Closer proximity often indicates related or shared disease pathways. Genetic factors making brain tissues or cells more susceptible to COVID infection were also considered.
Notably, people carrying the specific gene variation APOE E4/E4 showed decreased expression of antiviral defense genes. This suggests such individuals may be more susceptible to COVID-19. APOE E4/E4 just so happens to also be considered the number one genetic risk factor for Alzheimer’s.
“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,” Dr. Cheng concludes.
Moving forward, Dr. Cheng and his team have already begun further work focusing on ways to quickly identify and treat individuals at a greater risk of post-COVID neurological issues.
The study is published in Alzheimer’s Research and Therapy.