Serum YKL-40 as a Potential Diagnostic and Prognostic Biomarker in Asthma: Correlations with Exacerbation, Inflammatory Markers, and Disease Severity

Background:YKL-40 is a new marker that plays a role in tissue remodeling and airway inflammatory processes.
Objective: The objective wasevaluatingYKL-40 serum levels in children with bronchial asthma, its predictive value for asthma exacerbation, and its correlation with other inflammatory parameters.Patients and Methods: 84 patients with bronchial asthma (34 acute, 50 stable) and 60 healthy children as controls were recruited. YKL-40 levels were measured using an ELISA kit, analyzing correlations with inflammatory parameters. Results:Serum YKL-40 levels in asthmatic patients were significantly higher than in non-asthmatic individuals (p < 0.001), demonstrating excellent diagnostic accuracy; the area under the curve (AUC) was 1. At a cutoff of 11.9 ng/mL, YKL-40 exhibited 100% sensitivity and 98% specificity. Higher levels were observed in patients with exacerbations (p < 0.001) and a history of hospitalizations or intensive care unit (ICU) admissions (p = 0.03, p < 0.001 respectively). Positive correlations were found with ICU admissions (r = 0.34, p < 0.001) and inverse correlations with asthma control test (ACT) score (r = -0.62, p < 0.001). YKL-40 was also associated with inflammatory markers and predicted exacerbations (AUC = 0.73, p < 0.001) at a cutoff of 20.2 ng/mL (sensitivity 79%, specificity 65%).Conclusion:YKL-40 could serve as a potential biomarker for asthma exacerbation prediction and may provide valuable insights into disease severity and inflammation.