Elevated Neutrophil-to-Lymphocyte Ratio Is Associated with Severe Asthma Exacerbation

Abstract

<bold>Background:</bold> Asthma stands as the prevailing chronic respiratory ailment among young adults. While the neutrophil-to-lymphocyte ratio (NLR) serves as an indicator of chronic inflammation, its correlation with acute asthma exacerbations remains unexplored. <bold>Methods:</bold> This is a retrospective study, between 2017 to 2024, encompassed patients referred to our pulmonology department, for asthma exacerbation. NLR, derived from complete blood count upon arrival, was evaluated both as a continuous measure and categorized into quartiles. We examined the relationship between NLR quartiles and parameters of severity. <bold>Results:</bold> We included 85 patients hospitalized for asthma exacerbation. Quartiles 1–4 exhibited mean NLR values of 1.69; 3.06; 5.31. 13.81 respectively. Patients were younger in the 4th quartile (p= 0.036). Demographic characteristics, comorbidities, and chronic medications demonstrated similarity across quartiles. Elevated heart rate, and respiratory rate, and low oxygen saturation were observed in higher NLR quartiles, but without significant difference. Eosinophil count and eosinophil-to-lymphocyte ratio were higher in the 2nd and 3rd quartiles. Prolonged hospital stay was observed in higher quartiles (p= 0,024). <bold>Conclusion:</bold> In essence, NLR upon admission correlates with the severity of asthma exacerbations, with higher probability of prolonged hospitalization.