Age-dependent changes in pattern recognition receptor and cytokine mRNA expression in children with otitis media with effusion

ObjectiveTo investigate age-dependent changes in expression of pattern recognition receptors (PRRs) and cytokines in pediatric OME.Materials and methodsNinety five pediatric patients with OME were divided into 4 age groups: 0–2, 2–4, 4–7, and over 7 years. The presence of bacteria, and the levels of expression of mRNAs encoding Toll-like receptor (TLRs), NOD like receptors (NLRs) and cytokines in middle ear fluid were assessed, as were their correlations with age, gender, presence of bacteria and accompanying disease.ResultsBacteria were detected in 32.6% of patients. The levels of expression of PRR and cytokine mRNAs tended to be lower in children aged 2–4 and 4–7 years. The levels of expression of TLR-2, TLR-9, NOD-1, NOD-2, IL-1, IL-6, and TNF-α mRNAs in effusion fluid were significantly lower in these two groups than in children aged 0–2 and over 7 years (p < 0.05 each). The levels of expression of TLR-4, TLR-5, TLR-9, and NOD-1 mRNAs were significantly lower in culture positive than in culture negative patients (p < 0.05 each). However, the expression levels of PRR and cytokine mRNAs were unrelated to gender and accompanying disease (p > 0.05 each).ConclusionsThe levels of expression of PRR and cytokine mRNAs differed by age in children with OME.