Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses
The study titled “Para-infectious brain injury in COVID-19 persists at follow-up despite attenuated cytokine and autoantibody responses” investigates the neurological complications associated with COVID-19.
The key findings of the study are:
- Study Cohort and Methods: The study examined 203 hospitalized participants with COVID-19, including those with and without neurological complications, and compared them to 60 uninfected controls. It focused on measuring brain injury markers, inflammatory mediators, and autoantibodies.
- Neurological Complications in COVID-19: Early in the pandemic, neurological complications were noted in a significant proportion of hospitalized COVID-19 patients. These complications ranged from mild symptoms like headache to more severe conditions such as encephalitis, stroke, and Guillain-Barre Syndrome. The study suggests these effects are likely due to indirect mechanisms like inflammatory mediators, immune cells, autoantibodies, and blood-brain barrier changes, rather than direct viral invasion of the brain.
- Elevated Brain Injury Markers: The study found that brain injury markers (GFAP, NfL, tTau, and UCH-L1) were significantly higher in COVID-19 patients compared to controls. Particularly, markers of dendritic and axonal injury (tTau and NfL) were notably higher in patients with reduced consciousness. These markers remained elevated in the early and late convalescent phases in participants who had acute neurological complications due to COVID-19, suggesting ongoing neuroglial injury.
- Inflammatory Mediators and Neurological Injury: The study observed that certain inflammatory mediators (IL-6, HGF, IL-12p40, IL-1RA, CCL2, and M-CSF) were elevated in participants with abnormal Glasgow Coma Scale (GCS) scores, indicating increased innate inflammation. These mediators showed a strong correlation with brain injury markers, especially during the acute phase of COVID-19.
- Autoantibodies and Neurological Dysfunction: The study also noted a general increase in antibody production in COVID-19 patients, with specific autoantibodies more common in those with neurological complications. Interestingly, these autoantibodies did not show significant associations with brain injury markers but tended to correlate with each other. This suggests a nonspecific antibody response during the acute phase.
- Conclusions and Implications: The study concludes that COVID-19 is associated with quantifiable neuroglial injury markers, more pronounced in patients with neurological dysfunction during the acute phase and persisting in those with acute neurological complications. These findings suggest potential targets for therapy, highlighting the importance of considering both innate and adaptive immune responses in managing COVID-19-related neurological complications.
In summary, this comprehensive study provides valuable insights into the neurological impact of COVID-19, emphasizing the role of inflammatory mediators and autoantibodies in these complications, and suggests new avenues for therapeutic intervention.
Read More: https://www.nature.com/articles/s41467-023-42320-4