THE ROLE OF INFLAMMATORY MARKERS AND INNATE IMMUNITY PARAMETERS IN PREDICTING THE SEVERITY OF COMMUNITY-ACQUIRED PNEUMONIA IN CHILDREN

Abstract

Introduction. Community-acquired pneumonia (CAP) is one of the most common respiratory infections in children and remains a major challenge in contemporary pediatrics. Assessing the risk of severe disease and predicting treatment outcomes in pediatric patients is of practical importance. Immunological biomarkers – including immunoglobulins, cellular subpopulations, and inflammatory indicators – play a key role in the pathogenesis of CAP and help characterize the immune response and disease severity. Objective. To evaluate the diagnostic and prognostic value of inflammatory markers and innate immunity parameters in children with varying severity of community-acquired pneumonia (CAP). Materials and Methods. The study included 80 children aged 1 month to 3 years with a clinically and radiologically confirmed diagnosis of CAP. Patients were divided into two groups based on disease severity: 40 children with mild CAP and 40 with severe CAP. Severity stratification was performed using clinical criteria, including respiratory rate, degree of intoxication, presence of respiratory failure, and oxygen therapy requirement. Plasma levels of procalcitonin and C-reactive protein, along with immunological parameters – CD16+, CD64+, and neutrophil phagocytic activity—were assessed as indicators of inflammation and innate immunity. Results. Significant differences were found between mild and severe CAP groups in leukocyte count, absolute lymphocyte count, procalcitonin and C-reactive protein concentrations, CD64+ expression, and neutrophil phagocytic activity. Elevated leukocytes, procalcitonin, C-reactive protein, and CD64+ expression (p<0.001) were associated with severe disease, while lymphopenia reflected impaired adaptive immunity (p<0.001). Phagocytic activity was also higher in severe cases (p<0.001). CD16+ did not reach statistical significance, though a tendency toward increased levels was observed. The most informative combination of markers included leukocyte count, procalcitonin/CRP, CD64+, phagocytosis, and lymphocyte count. Conclusion. A combined assessment of inflammatory and immunological biomarkers provides high diagnostic value for early risk stratification of severe CAP in children. The most significant predictors were leukocytosis, lymphopenia, elevated procalcitonin, C-reactive protein, and CD64+, as well as enhanced neutrophil phagocytic activity. Incorporating this biomarker panel may improve early identification of patients requiring intensive monitoring and therapy. The role of CD16+ warrants further investigation.