Decreased pattern-recognition receptor-mediated cytokine mRNA expression in obese children with otitis media with effusion

Objectives. To assess innate and humoral immune responses in middle ear effusion of obese pediatric patients with otitis media with effusion (OME). Methods. We evaluated 219 children with OME, of whom 21 were obese and 198 were non-obese. We compared the expression in middle ear effusion of mRNAs encoding toll-like receptors (TLR) 2, 4, 5, and 9; nucleotide-binding oligomerization domains (NOD) 1 and 2; retinoic acid-inducible gene (RIG)-I; interleukins (IL)-6, -10, and -12; interferon (IFN)-γ; and tumor necrosis factor (TNF)-α mRNAs. We also compared the expression of immunoglobulins IgG, IgA, and IgM and the bacterial detection rate in the two groups. Results. TLR2-mediated expression of IL-6 mRNA, TLR4-mediated expression of IL-6 and IL-10 mRNA, TLR5-mediated expression of IL-6, IL-10, and TNF-α mRNA, TLR9-mediated expression of IL-6 mRNA, and NOD2-mediated expression of IL-6, IL-12, and TNF-α mRNA were significantly lower in obese than in non-obese children (P<0.05). However, concentrations of IgG, IgA, and IgM in middle ear effusion were lower in obese than in non-obese children, but none of these differences was significant (P>0.05). Conclusion. Mean body mass index was higher and pattern-recognition receptor-mediated cytokine mRNA expression was lower in obese than in non-obese children with OME.