The Role Of OPG And RANKL On Tympanosclerosis

Background: Tympano/myringosclerosis is a sequelae following a long time of chronic otitis media. It is the retrogression of middle ear connective tissue in the healing process. Characterized by a hyalinization and calcification of the intermediate and(or) submucosa connective tissue layer. Its etiology is unknown. Due to the similarities of the pathological changes under optical microscope between myringosclerosis and the formation new bone, Several investigations have demonstrated that the end-stage of myringosclerosis is the formation of new bone. OPG/RANKL system is one of the pathways deciding to bone remodeling direction, and it is associated to the progress of myringosclerosis. Purpose: The study objective was to assess the relationship between osteoprotegerin(OPG)/receptor activator nuclear kappa B ligand(RANKL) system and myringosclerosis.And to assess the relationship between their expression levels and the mechanism of sclerosis. Furthermore,to explore if the change of OPG/RANKL contribute to promote myringosclerosis progress.Methods: Patients with myringosclerosis(n=25) treated surgically were included in the study,and collect the Calcified plaque. Meanwhile normal tissue(n=9)and granulation tissue in the tympanic cavity(n=13) were included. Immunohistochemistry and HE were used to detect the expression of RANKL and OPG. Results : OPG and RANKL were expressed in all myringosclerosis,normal subcutaneous and granulation tissues. Positive expression were mainly seen in endothelial cells, epithelial cells and inflammatory cells of the sclerosis tissues, and inflammatory cells, fat cells, endothelial cells of the controlled group. The OPG protein level in the sclerosis group was higher than in the others. The RANKL protein level were the same. The ratio of OPG/RANKL in the sclerosis group(1.10±0.29) was higher than in the control group(0.90±0.31). Conclusions: The OPG protein level in the sclerosis group was higher than in other groups, and the RANKL are the same. OPG did not elevate progressively, and inflammatory granulation is not the middle process of myringosclerosis.Increasing OPG level and the ratio of OPG/RANKL may advance inflammation reaction, which finally involved in the etiology of myringosclerosis.