Expression Of TLR4 And IL-12 In The Hypertrophic Adenoids And Their Significance In Secretory Otitis Media

Objective:To investigate the expression of toll-like receptor 4 (TLR4) in puerile hypertrophic adenoids and the expression of interleukin-12 (IL-12) in adenoids and middle ear effusion (MEE), to approach the role of immunologic abnormality of adenoid hypertrophy in the pathogenesy of otitis media with effusion (OME).Methods:The specimens from 30 cases of puerile hypertrophic adenoids who underwent adenoidectomy, including 15 cases with and without secretory otitis media respectively, were collected. Meanwhile, the samples of tympanic cavity effusion from 15 cases of OME with adenoid hypertrophy and 15 OME alone were gathered. The expression of TLR4 mRNA in the hypertrophic adenoids were detected by reverse transcription polymerase chain reaction (RT-PCR), and the IL-12 levels in the middle ear effusion and homogenate of adenoids were measured by enzyme-linked immunosorbent assay (ELISA). A comparative study on the expression of TLR4 and the level of IL-12 between groups were performed.Results:TLR4 mRNA expressed in all the specimens of hypertropic adenoids, although there were substantial differences between individuals. The expression of TLR4 mRNA in the hypertrophic adenoids with OME was significantly higher than that in hypertrophic alone (P<0.05), and the hypertrophic heavier, the expression level higher. In the children of adenoid hypertrophy with OME, The IL-12 levels in middle ear effusion were lower than that in the cases of OME alone (P<0.05), while in adenoid homogenates, the IL-12 levels higher than that in the patients of adenoid hypertrophy alone (P<0.05). There was a positive correlation between the expression of TLR4 and IL-12 levels in the adenoid samples from the cases of adenoid hypertrophy with OME (r=0.901, P<0.05).Conclusions:There were stronger expressions of TLR4 in the heavier adenoid hypertrophy and in combined with OME. In the middle ear effusion, IL-12 levels in OME combined with adenoid hypertrophy were lower than that in OME alone, but in the adenoid homogenates, higher than that in adenoid hypertrophy alone. There was a significant correlation between the expression of TLR4 mRNA and IL-12 in adecoid hypertrophy with OME. These results suggested that TLR4-mediated immunoreaction may play a role in the pathogenesy of OME induced by adenoid hypertrophy via regulating the contents of IL-12 of nasopharynx and tympanic cavity.