Induced sputum levels of IL-33 and soluble ST2 in young asthmatic children

• Published in: The Journal of asthma 2013-10, Vol.50 (8), p.803-809
• Main Authors: Hamzaoui, Agnes, Berraies, Anissa, Kaabachi, Wajih, Haifa, Maalmi, Ammar, Jamel, Kamel, Hamzaoui
• Format: Article
• Language: English
• Subjects: Adolescent; Asthma - immunology; Child; Child, Preschool; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunopathogenesis; Inflammation - immunology; Interleukin-1 Receptor-Like 1 Protein; Interleukin-33; Interleukins - immunology; Male; pediatrics; phenotypes; Real-Time Polymerase Chain Reaction; Receptors, Cell Surface - immunology; RNA, Messenger - chemistry; RNA, Messenger - genetics; Sputum - immunology; Statistics, Nonparametric; Tumor Necrosis Factor-alpha - genetics; Tumor Necrosis Factor-alpha - immunology
• ISSN: 0277-0903; 1532-4303
• DOI: 10.3109/02770903.2013.816317

Abstract Objective: Interleukin-33 is an IL-1 family cytokine which signals via its T1/ST2 receptor, and acts as a key regulator of inflammation, notably the type-2 response implicated in asthma. This study aims to measure the expression of soluble ST2 (sST2) and IL-33 in asthmatic children, depending on disease activity. Methods: Thirty-seven children with well-defined asthma (20 moderate and 17 mild asthmatics) were studied. IL-33 and sST2 were measured by ELISA in serum and induced sputum (IS) samples, and compared with 22 age- and sex-matched healthy controls. Real-time quantitative PCR was used to determine IL-33 and TNF-α mRNA expression in IS. Results: sST2 and IL-33 levels in IS and serum were significantly higher in patients compared with healthy controls (p = 0.0001). The increase in sST2 and IL33 was significantly more important in moderate cases than in mild asthma. A significant correlation was observed between serum and IS IL-33 levels (r = 0.497; p = 0.0018). Higher levels of IL-33 mRNA were detected in IS from asthmatics than those observed in controls. A significant correlation was found between TNF-α and IL-33 mRNA expression in the asthmatic subjects (r = 0.772, p = 0.0001). Conclusions: Values of sST2 and IL-33 observed in IS were found to correlate with disease activity. Elevated IL-33 mRNA expression in IS and its correlation with TNF-α reflected the inflammatory process observed in the lung of young asthmatics.