Neuroinflammation in Severe COVID-19: The Dynamics of Inflammatory and Brain Injury Markers During Hospitalization

Patients with COVID-19 can develop excessive inflammation in the brain and consequent neurological complications. The aim of this study was to evaluate the inflammatory, endothelial and brain injury markers in hospitalized COVID-19 patients and compare those with or without neurological symptoms. A total of 30 intensive care unit (ICU) COVID-19 patients were allocated into COVID-19 (without neurological symptoms) or neuro-COVID-19 (with neurological symptoms) groups. Patients with respiratory infection symptoms but negative for COVID-19 were included as a control group. Peripheral blood samples were collected at hospital admission (T1) (controls and ICU patients) and during hospitalization (T2: last 72 h before hospital discharge or in-hospital death) (ICU COVID-19 patients) to analyze inflammatory markers. Higher ICAM-1, CCL26 and VEGF at T1 were identified in both COVID-19 groups compared with control. Neuro-COVID-19 patients presented lower systemic BDNF levels compared with the control group and increased S100B compared with the control and COVID-19 groups. BDNF levels in survivors were lower in the neuro-COVID-19 group compared to the COVID-19 group, while S100B were higher, regardless of the outcome. In addition, all COVID-19 patients presented increased ICAM-1 and CCL26 levels over the hospitalization period (T2 > T1). Furthermore, S100B, ICAM-1, CCL26 and VEGF levels increased in relation to T1 in neuro-COVID-19 patients, with S100B and CCL26 being significantly higher in relation to the COVID-19 group. In conclusion, high levels of brain injury biomarkers were found in patients with neuro-COVID-19, indicating neuroinflammatory and consequent brain injury in the last 72 h of hospitalization.