ABSTRACT
CONCLUSION: Overexpression of receptor activator of nuclear factor-κB ligand (RANKL) and low expression of osteoprotegerin (OPG) are typical features in middle ear cholesteatoma patients. The altered RANKL/OPG protein ratio suggests that alterations in the RANKL-OPG pathway may be major factors in the pathogenesis of middle ear cholesteatoma. OBJECTIVE: Our meta-analysis explored the contribution of one important cytokine pathway, the RANKL and OPG pathway, in the development of middle ear cholesteatoma. METHODS: We screened Embase, the Cochrane Library, CISCOM, CINAHL, Google Scholar, China BioMedicine, China National Knowledge Infrastructure, PubMed, and Web of Science for relevant articles. RANKL expression and ratio of RANKL/OPG were analyzed using Comprehensive Meta-Analysis Version 2 software. RESULTS: The electronic literature search identified five studies that contained information on the correlation of RANKL and OPG expression with middle ear cholesteatoma. Increased RANKL expression positively correlated with middle ear cholesteatoma, while OPG expression showed an inverse association (p < 0.05). The ratio of RANKL/OPG in middle ear cholesteatoma cases was higher than in healthy controls, indicating that our observations are applicable to each individual case. Subgroup analysis based on country of study revealed that OPG levels decreased in China and Korea, and high RANKL expression was found in Poland, China, and Korea (all p < 0.05).
