ON THE ISSUE OF NEUROINFLAMMATION IN SEVERE COMMUNITY-ACQUIRED PNEUMONIA

Introduction. ommunity-acquired pneumonia (CAP) continues to represent a significant medical and social burden, remaining a common cause of adult hospitalization, temporary disability, and adverse outcomes. Severe CAP poses a particular clinical challenge, as local lung inflammation rapidly becomes systemic, leading to severe hypoxemia, respiratory failure, and the need for intensive care. The severe course of CAP is associated with systemic inflammation and may involve neuroimmune effects, potentially reflected by circulating neuroproteins. Aim of the Study. The aim of this study was to evaluate the levels and dynamics of serum S100B, brain-derived neurotrophic factor (BDNF), and neuron-specific enolase (NSE) in patients with CAP and their association with clinical indicators of severe disease. Materials and Methods. A comparative observational study was conducted, including 51 hospitalized patients with CAP. Patients were divided into two groups: severe CAP (n=24) and moderate CAP (n=27). Severe CAP was defined by the presence of the following clinical criteria: hospitalization in the Intensive Care Unit (ICU), septic state, respiratory failure, or obstructive syndrome. Blood samples were collected on days 1, 3, 6, 9, and 12. Concentrations of S100B, BDNF, and NSE were measured using enzyme-linked immunosorbent assay (ELISA) with commercial kits. Statistical analysis involved reporting data as Median [Interquartile Range] (Me [Q1;Q3]), using the Mann-Whitney U test for intergroup comparisons, and the Wilcoxon signed-rank test for paired comparisons; p<0.05              was                         considered               statistically                         significant. Results. On day 1, no significant differences were observed between the groups for S100B, BDNF, and NSE levels. Over time, S100B levels were higher in the severe CAP group on days 3 and 6. In the moderate CAP group, a decrease in S100B was noted from day 1 to day 3 (n=18; p=0.024). No significant differences were found for BDNF; however, on day 3, a trend towards higher values was observed in the moderate CAP group (p=0.056). Intergroup differences for NSE were not significant on days 1–6; however, an increase in NSE was observed from day 1 to day 6 in the severe CAP group (n=17; p=0.009). The most consistent finding in severe CAP was an elevation of S100B on days 3–6, highlighting the informative value of dynamic monitoring of this marker during the early hospitalization period. Conclusions. The findings should be considered preliminary and require confirmation in a larger cohort with more comprehensive dynamics and linkage to clinical endpoints to clarify the role of neuroproteins in the comprehensive assessment of CAP severity.