title: Subepithelial inflammatory load and basement membrane thickening in refractory chronic rhinosinusitis with nasal polyposis: a histopathological study.
abstract: BACKGROUND
  A subgroup of chronic rhinosinusitis with nasal polyps (CRSwNP) patients is refractory to optimal surgical therapy and requires multiple revision sinus operations. Studies have shown that mucosal eosinophilia correlates with disease severity. We hypothesized that a high-grade tissue inflammatory load is associated with these refractory patients.
  
  
  METHODS
  A single-surgeon, retrospective case-control study comparing 20 CRSwNP patients requiring a second surgery during follow-up (refractory group) vs a matched cohort of 20 CRSwNP patients without needing further revision surgery (control group). Hematoxylin and eosin (H&E)-stained tissue harvested intraoperatively (×2 for the refractory group) were recalled for histopathological examination of subepithelial inflammation and basement membrane (BM) thickness.
  
  
  RESULTS
  The refractory group had a significantly higher average eosinophil count (49 vs 18), relative eosinophilia (55% vs 32%) as well as total inflammatory cell count (86 vs 49) than the control group (p < 0.05). However within the refractory group, the eosinophil-lymphocyte ratio was reduced from their first to their second (revision) surgeries whereas the total averaged inflammatory cell count remained unchanged. No significant difference in BM thickness was found between the groups.
  
  
  CONCLUSIONS
  These findings suggest that a higher inflammatory and eosinophilic load is associated with refractory disease and thus may be useful in predicting need for future revision surgery in CRSwNP.
authors.affiliation: Department of Surgery-Otorhinolaryngology, Head & Neck Surgery, University of Adelaide, Adelaide, Australia.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Bassiouni
authors.affiliation: Department of Surgery-Otorhinolaryngology, Head & Neck Surgery, University of Adelaide, Adelaide, Australia.
authors.forename: Judy
authors.initials: J
authors.lastname: Ou
authors.affiliation: Department of Surgery-Otorhinolaryngology, Head & Neck Surgery, University of Adelaide, Adelaide, Australia.
authors.forename: Sukanya
authors.initials: S
authors.lastname: Rajiv
authors.affiliation: Department of Surgery-Otorhinolaryngology, Head & Neck Surgery, University of Adelaide, Adelaide, Australia.
authors.forename: Daniel
authors.initials: D
authors.lastname: Cantero
authors.affiliation: Department of Surgery-Otorhinolaryngology, Head & Neck Surgery, University of Adelaide, Adelaide, Australia.
authors.forename: Sarah
authors.initials: S
authors.lastname: Vreugde
authors.affiliation: Department of Surgery-Otorhinolaryngology, Head & Neck Surgery, University of Adelaide, Adelaide, Australia.
authors.forename: Peter-John
authors.initials: PJ
authors.lastname: Wormald
mesh_terms: D000328:Adult; D001485:Basement Membrane / Q000473:pathology*; D016022:Case-Control Studies; D002908:Chronic Disease; D004804:Eosinophils / Q000276:immunology*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009297:Nasal Mucosa / Q000276:immunology* / Q000473:pathology; D009298:Nasal Polyps / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D011183:Postoperative Complications / Q000473:pathology*; D012086:Reoperation; D012189:Retrospective Studies; D012220:Rhinitis / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D012225:Rhinoplasty; D012852:Sinusitis / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery
keywords: basement membrane thickness; chronic rhinosinusitis; chronic rhinosinusitis with nasal polyposis; endoscopic sinus surgery; inflammatory load; mucosal eosinophilia; nasal polyposis