Immune recovery following bronchiolitis is linked to a drop in cytokine and LTC4 levels

• Published in: Pediatric research Vol. 87; no. 3; pp. 581 - 587
• Main Authors: Sastre, Beatriz, García-García, María Luz, Calvo, Cristina, Casas, Inmaculada, Rodrigo-Muñoz, José Manuel, Cañas, José Antonio, Mora, Inés, Del Pozo, Victoria
• Format: Journal Article
• Language: English
• Published: United States Nature Publishing Group 01.02.2020; Nature Publishing Group US
• Subjects: Adaptive Immunity; Biomarkers; Biomarkers - metabolism; Bronchiolitis - diagnosis; Bronchiolitis - immunology; Bronchiolitis - metabolism; Bronchiolitis - therapy; Clinical; Cytokines; Cytokines - genetics; Cytokines - metabolism; Down-Regulation; Female; Gene expression; Humans; Immunity, Innate; Infant; Leukotriene C4 - metabolism; Male; Nasopharynx - immunology; Prospective Studies; Proteins; Time Factors
• ISSN: 0031-3998; 1530-0447
• DOI: 10.1038/s41390-019-0606-2

Bronchiolitis is the main cause of hospitalization of children younger than 1 year; however, the immune mechanism of bronchiolitis is not completely understood. The aim of this study was to analyze the recovery of immune response after a bronchiolitis episode. Forty-nine infants hospitalized with bronchiolitis diagnosis were enrolled. Nasopharyngeal aspirates (NPAs) were processed. Twenty-seven pro-inflammatory biomarkers linked to innate immunity, inflammation, and epithelial damage, as well as nitrites and lipid mediators, were evaluated in the NPA supernatant by ELISA (enzyme-linked immunosorbent assay) and Luminex. Also, 11 genes were analyzed in NPA cells by quantitative PCR. A widespread statistically significant decline of multiple pro-inflammatory parameters and cytokines were detected in the recovery period after respiratory infection: interferon-α2 (IFNα2), IFNγ, interleukin-10 (IL-10), IL-1β, IL-8, IFN-γ-inducible protein-10, vascular endothelial growth factor, monocyte chemoattractant protein-1, macrophage inflammatory protein-1α (MIP-1α), and MIP-1β. Supporting these results, a decreased nuclear factor-κB gene expression was observed (P = 0.0116). A significant diminution of cysteinyl leukotriene C4 (LTC4) soluble levels (P = 0.0319) and cyclooxygenase-2 (COX-2) gene expression were observed in the recovery sample. In children classified by post-bronchiolitis wheezing, LTC4 remains elevated in the NPA supernatant. After bronchiolitis, cytokines and biomarkers linked to innate immune response in NPA decrease significantly in the recovery period accompanied by a drop in LTC4 levels; however, this reduction was lower in infants with post-bronchiolitis wheezing.