A Prospective Study on Neural Biomarkers in Patients with Long-COVID Symptoms

Background: this prospective observational study aims to assess serum levels of glial fibrillary acidic protein (GFAP), s100b, and total Tau in long-COVID patients, exploring correlations with symptoms, cognitive decline, mental health, and quality of life. Methods: Long-COVID patients visiting our outpatient clinic (February 2021-December 2022) were screened alongside age- and sex-matched controls. GFAP, s100b, and total Tau in serum were measured with ELISA. Cognitive function, depression, anxiety, post-traumatic stress disorder, and quality of life were evaluated using MoCA, HADS (depression and anxiety), IES-R, and SF-36, respectively. Results: Sixty-five long-COVID patients and 20 controls were included. GFAP levels were significantly higher in long-COVID patients (p = 0.031), though not correlating with the presence of long-COVID symptoms. S100b and total Tau showed no significant differences between patients and controls. Nervous system-related symptoms were reported in 47% of patients. High rates of cognitive decline (65.9%), depression (32.2%), anxiety (47.5%), and post-traumatic stress disorder (44.1%) were observed. Over 80% of the study population scored below normative cutoffs for SF-36, indicating a significant impact on quality of life. Conclusions: in this long-COVID cohort with substantial psychological and cognitive symptoms, GFAP levels were elevated compared to controls, though not correlating with the presence of long-COVID symptoms.