Biomarcadores de neuroinflamação em pacientes com COVID-19 e doenças neurológicas

Abstract

The new coronavirus pandemic has had a major economic and psychosocial impact. In addition to the characteristic respiratory symptoms of COVID-19, studies have reported the presentation of neurological symptoms. In this sense, some biomarkers are used in research in order to investigate their role as probable methods of early diagnosis or prognosis. Among these, some markers that have already demonstrated a role in the pathophysiology of COVID-19 or other neurological diseases are GFAP, HMGB1, RAGE and COX-2. Both play a role not only in inflammation but also in oxidative stress. Therefore, the objective of this thesis was to carry out a survey of the literature, including studies that evaluated serum levels of GFAP in neurological diseases (study 1); and to assess plasma levels of GFAP, HMGB1, RAGE and COX- 2 in patients with COVID-19 (study 2). For the systematic review, a search was performed in the Pubmed, Scopus and Web of Science databases using the descriptors “GFAP” OR “glial fibrilary acid protein” AND “neurological” OR “neurodegenerative” AND “plasma” OR “serum”. As a result, 48 studies evaluating 18 different neurological diseases were included. Of these, two did not find an increase in GFAP levels, 10 identified an increase in their serum levels and 26 articles demonstrated, in addition to an increase in GFAP levels, its relationship with the severity of the disease. Diseases in which GFAP was related to intensity were multiple sclerosis, frontotemporal dementia, schizophrenia, autism, epilepsy, major depressive disorder, asthma, and COVID-19. Demonstrating the importance of serum GFAP levels in several neurological diseases, despite its uncertain role in predicting the severity of some diseases. As for the second study, first, the demographic data of the people who consented with participation in the research were recorded. All those involved were tested for COVID-19, and blood samples were collected to measure biomarkers through Western blot. In total, 93 people were included, of which 34 were from the healthy control group (CTR), 19 with COVID-19 with mild to moderate symptoms (IgM+), 17 with a history of COVID-19 (IgG+) and 23 from the severe COVID-19 (ICU). A significant increase in GFAP, GFAP-BDP, RAGE, HMGB1 and COX-2 levels was observed in patients in the ICU group compared to the control group and, for some markers, a difference was also observed in relation to the groups with mild to moderate COVID and /or IgG+ group. Furthermore, a correlation was found between the RAGE, HMGB1 and GFAP markers. In agreement with what was observed in the review, GFAP levels, in addition to HMGB1, RAGE and COX-2 levels, were related to the severity of COVID-19. Which indicates the potential use of these markers for diagnostic purposes, prognosis of nerve alterations or as targets for new therapeutic interventions.