D3.112 - Clinical Characteristics and Evaluation of Serum Inflammatory Markers in Patients Hospitalized Due to Asthma Exacerbations

Asthma is a chronic inflammatory disease of the airways. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic immune-inflammation index (SII) are easily accessible hematological parameters that can reflect systemic inflammation. This study aimed to compare these inflammatory markers during asthma exacerbations and stable period in children hospitalized due to asthma exacerbations.

This retrospective study included patients who were hospitalized for asthma exacerbations between January 1, 2024, and January 1, 2025, and who were consulted by the Pediatric Immunology and Allergic Diseases Clinic. Clinical characteristics and inflammatory markers [NLR, PLR, and SII (platelet × neutrophil / lymphocyte) levels] measured at admission and at a stable outpatient visit ≥1 month after discharge were evaluated.

A total of 72 patients were included; the median age was 60.5 months (IQR: 30.5–113), and 36.1% were male. Concomitant allergic diseases included allergic rhinitis in 19.4%, atopic dermatitis in 9.7%, and food allergy in 2.8% of patients. A history of recurrent wheezing was present in 77.8% (n=56). Respiratory pathogen panel positivity was detected in 55.6% of patients, with rhinovirus being the most frequently identified pathogen. The rate of atopy was 41%.

During asthma exacerbations, leukocyte and neutrophil counts were significantly higher, compared with the stable period. Inflammatory indices were significantly elevated during exacerbations: NLR 5 (2–10) vs. 0.99 (0.58–1), PLR 187 (123–320) vs. 102 (79–135), and SII 1987.5 (926.7–3893.7) vs. 346.5 (211.2–534) (all p<0.005). In patients with atopy, SII, NLR, and PLR levels were significantly higher during exacerbations, while no significant differences were observed during the stable period. No significant association was found between asthma severity and inflammatory indices in either the stable or exacerbation periods.

NLR, PLR, and SII levels were significantly higher during asthma exacerbations compared with the stable period. These low-cost and easily accessible hematological markers may be useful in reflecting systemic inflammation during asthma exacerbations in children and may contribute to clinical decision-making, although prospective studies are needed to validate their clinical utility and to determine optimal cut-off values.