Effect of IL-12 on Experimental Allergic Otitis Media with Effusion

Objective: To investigate the role of IL-12 in the pathogenesis of Otitis media with effusion (OME) in animal model induced by ovalbumin. Methods: Twenty-four Sprague-Dawley (SD) rats were randomly divided into three group as OME group, IL-12 group, and control group. The rats of OME group were sensitized to OVA via intraperitoneal injection once a week for two weeks and then challenged transtympanic. The rats of IL-12 group and control group were sensitized and challenged in the same way, but before challenge they were injected IL-12 and PBS transtympanic respectively. The histomorphologic changes of middle ear mucosa were observed with histochemical technique. The level of IL-4 and IL-5 was measured by immunohistochemistry. Results: Tympanal mucosa in OME group and control group rats thickened significantly. Meanwhile, inflammatory cells infiltrated obviously. Such histological findings were abated to absent in IL-12 group. The level of IL-4 and IL-5 in OME group and control group was higher significantly than in IL-12 group. Conclusion: The local application of IL-12 is effective in attenuating allergic inflammation of middle ear. It can be used as a novel treatment for allergic OME.