title: Histopathological and clinical analysis of chronic rhinosinusitis by subtype.
abstract: BACKGROUND
  Chronic rhinosinusitis (CRS) encompasses diverse phenotypic expression. Clinical and histological differences suggest 4 CRS subtypes: eosinophilic CRS with and without nasal polyps (eCRSwNP, eCRSsNP, respectively) and non-eosinophilic CRS with and without nasal polyps (neCRSwNP, neCRSsNP, respectively). The mucosal basement membrane (BM) and cilia are believed to play roles in CRS pathogenesis by impacting mucociliary clearance and immune barriers. This study aimed to identify clinical, surgical, and histopathological subtype differences to further elucidate disease mechanisms.
  
  
  METHODS
  Ethmoid tissue from 33 adult CRS patients and 7 controls was obtained during endoscopic sinus or other sinonasal surgery (controls) and analyzed by light and transmission electron microscopy for BM thickness and presence of cilia. CRS patients were categorized into the 4 subtypes, and 22-item Sinonasal Outcome Test (SNOT-22) score, endoscopy, computed tomography (CT), and surgical data were compared and analyzed for association with histopathology measures.
  
  
  RESULTS
  CRS subtypes could be distinguished by CT score and surgical data, with eCRSwNP patients exhibiting greatest disease severity. Whereas eosinophilia was associated with absence of cilia, nasal polyposis showed no association with surgical or histopathological measures. No significant difference in BM thickness was found between controls and CRS subtypes, but distinctions were found regarding cilia, which were less common in eosinophilic subgroups compared to controls and neCRSsNP patients.
  
  
  CONCLUSIONS
  CRS subtypes exhibit some differentiating histopathological and surgical features. The absence of cilia appears to have an important role in the eosinophilic subgroups. Further histologic evaluation is warranted to evaluate for possible subtype-specific treatment targets or prognostic markers.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Saint Louis University School of Medicine, St. Louis, MO.
authors.forename: Mary S
authors.initials: MS
authors.lastname: Czerny
authors.forename: Arya
authors.initials: A
authors.lastname: Namin
authors.forename: Michael Anne
authors.initials: MA
authors.lastname: Gratton
authors.forename: Jastin L
authors.initials: JL
authors.lastname: Antisdel
mesh_terms: D000328:Adult; D000368:Aged; D001485:Basement Membrane / Q000473:pathology; D002908:Chronic Disease; D002923:Cilia / Q000473:pathology; D003937:Diagnosis, Differential; D018450:Disease Progression; D004724:Endoscopy; D004804:Eosinophils / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009298:Nasal Polyps / Q000145:classification / Q000175:diagnosis*; D010256:Paranasal Sinuses / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D012220:Rhinitis / Q000145:classification / Q000175:diagnosis*; D012852:Sinusitis / Q000145:classification / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed
keywords: basement membrane; histology; nasal mucosa; nasal polyposis; nasal polyps; pathology; sinonasal polyposis; sinusitis