Influence of Matrix Metalloproteinases content on eardrum atrophy in Otitis Media with Effusion in children

Objectives Otitis media with effusion (OME) is a common pathology in children. Effusions contain Metalloproteinases (MMPs), which can lead to atrophy of the tympanic membrane (TM) due to destructive effect on the lamina propria. Not all cases of OME are complicated with atrophy, maybe explained by an inter-individual variation of MMP concentration in effusions. The purpose of this study was to determine the correlation between concentration of MMPs and existence of TM atrophy in children. Participants - Main outcome measures The effusion from thirty middle ears were collected during insertion of VT in children aged 15 months to 10 years, including 11 eardrums with tympanic atrophy and 19 without tympanic atrophy. ELISA tests were used to measure concentrations of MMP-2, MMP-7, MMP-9 and TIMP-2 in the effusions. Correlations between MMP levels and atrophy of eardrum was investigated, as well as correlation with age, gender, number of previous ventilation tube insertion, and viscosity of the glue. Results The mean concentration of MMP-2 was higher in the atrophic group than in effusions without TM atrophy (0.6 ng/mg versus 0.5 ng/mg total protein respectively), while the TIMP-2 concentration was lower in this group. The level of MMP-2 decreased with the age. Finally, a significantly higher concentration of MMP-9 and TIMP-2 was found in high-viscosity effusions. Conclusion This study suggests that MMP-2 activity could play an important role in destruction of the eardrum during OME in infancy. MMP-2 level assessment could be interesting for determining children with risk of lamina propria destruction.