Clinical characteristics and differential cytokine expression in hospitalized Taiwanese children with respiratory syncytial virus and rhinovirus bronchiolitis

Background: Viral bronchiolitis presents a heterogeneous spectrum. In this study, we investigated the clinical characteristics and the cytokines/chemokines profiles among res-piratory syncytial virus (RSV), rhinovirus (RV), and their dual infection in Taiwanese children with viral bronchiolitis.Method: This study was conducted between October 2014 and June 2017. Viral etiology was identified using a Luminex respiratory virus panel and blood cytokines were evaluated using a MILLIPLEX MAP Human Cytokine/Chemokine Panel. Cytokine/Chemokine expressions were compared by clinical severity, steroid treatment, and viral entities.Results: A total of 184 patients were evaluated; at least one respiratory virus was identified in 163 (88.6%) patients. RSV and RV were the two leading viral etiologies, with 25.5% and 17.3%, respectively. RV bronchiolitis has a comparable severity to RSV but is more common in children of an older age with a history of recurrent wheezing and blood eosinophilia. Decreased tumor necrosis factor-alpha (TNF-a) and interferon gamma (INF-g) levels were correlated with clin-ical severity. Patients infected with RV exhibited higher levels of Interleukin (IL)-22, IL-23, IL-25, IL-31, and IL-33 (p < 0.05), whereas those with RSV had higher levels of TNF-a, INF-g, and IL-10 (p < 0.05). Systemic steroid treatment was associated with higher expressions of IL-4, IL-8, IL-13, and MIP-1a levels (p < 0.05). Cluster analysis revealed a high correlation of IL -33 and IL-31(R2 Z 0.9731, p < 0.0001).Conclusion: Different viral infections elicited the characteristic clinical presentation and im-mune profiles in bronchiolitis. Our findings also highlight the role of the IL-33/IL-31 axis in the immunopathogenesis of bronchiolitis. Copyright 2022, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study investigated the clinical characteristics and cytokines/chemokines profiles among respiratory syncytial virus (RSV), rhinovirus (RV), and their dual infection in Taiwanese children with viral bronchiolitis. The findings revealed that RV bronchiolitis had comparable severity to RSV but was more common in older children with a history of recurrent wheezing and blood eosinophilia. Different viral infections elicited characteristic clinical presentations and immune profiles in bronchiolitis. The study also highlighted the role of the IL-33/IL-31 axis in the immunopathogenesis of bronchiolitis.