Differences in concentration of neuron-specific enolase (NSE), neutrophil elastase (NE), and calcium-binding protein S100B in viral diseases: a pilot study focused on normoglycemic COVID-19 patients.

SARS-CoV-2 infection is characterized by a wide spectrum of clinical severity. Despite more than 2 years having passed since the end of the COVID-19 pandemic, the virus's properties continue to form the basis for developing diagnostic and therapeutic models relevant to future epidemics. The aim of this study was to evaluate the diagnostic utility of classical inflammatory and metabolic markers, as well as potential variables associated with COVID-19 condition, such as neutrophil elastase (NE), neuron-specific enolase (NSE), and S100B protein. The analysis was conducted in carefully selected, homogeneous groups: the study group (patients with symptomatic COVID-19, without comorbidities) and the control group (healthy individuals, without comorbidities), with approximately 100 participants in each group. In the study group, significantly higher values were observed for numerous markers, including basophils, creatinine, eosinophils, HbA1c, HDL cholesterol, lymphocytes, monocytes, neutrophils, hemoglobin, hematocrit, platelets, as well as NSE and S100B. In a multivariate model assessing the likelihood of a result compared to the control group, monocyte count was positively associated with increased odds (OR = 1.6487; 95% CI: 1.2480-2.4318; p = 0.0001). Neutrophil count showed a positive association per 10-unit increase (OR = 1.0377; 95% CI: 1.0214-1.0622; p < 0.0001). Finally, NSE was also positively associated with increased odds (OR = 1.1466 per unit increase; 95% CI: 1.0175-1.2998; p = 0.0218).