title: Expression of IL-17 and its role in bone destruction in human middle ear cholesteatoma.
abstract: OBJECTIVE
  The present study was designed to elucidate the immunoreactivity and protein level of IL-17 in human cholesteatomas.
  
  
  METHODS
  The expression and localization of IL-17 and receptor activator of nuclear factor κB ligand (RANKL) were examined by immunohistochemistry in tissue specimens collected from 24 patients with cholesteatomas. The cellular sources of IL-17 were assessed by double staining with CD4. The level of IL-17 protein was determined using an enzyme-linked immunosorbent assay. The degree of bone destruction was compared with the IL-17 immunoreactivity.
  
  
  RESULTS
  IL-17 immunoreactivity was detected in the inflammatory cells in the granulation tissues and there were increased levels of IL-17 protein. The localization of IL-17 expression coincided with CD4-positive lymphocytes. IL-17 was correlated with the cells positive for RANKL. The degree of bone destruction was dependent on the number of infiltrated IL-17-positive cells. IL-17-driven pathology was observed in the congenital type as compared with the acquired type.
  
  
  CONCLUSIONS
  The present study suggests that IL-17 is related to the pathogenesis of the disease.
authors.affiliation: Department of Otorhinolaryngology, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Takuo
authors.initials: T
authors.lastname: Haruyama
authors.forename: Masayuki
authors.initials: M
authors.lastname: Furukawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kusunoki
authors.forename: Junko
authors.initials: J
authors.lastname: Onoda
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Ikeda
mesh_terms: D000328:Adult; D018424:Cholesteatoma, Middle Ear / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D004429:Ear Ossicles / Q000473:pathology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D020381:Interleukin-17 / Q000378:metabolism*; D008297:Male; D053245:RANK Ligand / Q000378:metabolism; D018709:Statistics, Nonparametric
chemical_list: D020381:Interleukin-17; D053245:RANK Ligand