Subepithelial inflammatory load and basement membrane thickening in refractory chronic rhinosinusitis with nasal polyposis: a histopathological study

Int Forum Allergy Rhinol. 2016 Mar;6(3):248-55. doi: 10.1002/alr.21661. Epub 2015 Nov 17.

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.

Conclusion: 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.

Keywords: basement membrane thickness; chronic rhinosinusitis; chronic rhinosinusitis with nasal polyposis; endoscopic sinus surgery; inflammatory load; mucosal eosinophilia; nasal polyposis.

MeSH terms

  • Adult
  • Basement Membrane / pathology*
  • Case-Control Studies
  • Chronic Disease
  • Eosinophils / immunology*
  • Female
  • Humans
  • Inflammation / immunology
  • Male
  • Middle Aged
  • Nasal Mucosa / immunology*
  • Nasal Mucosa / pathology
  • Nasal Polyps / diagnosis
  • Nasal Polyps / pathology*
  • Nasal Polyps / surgery
  • Postoperative Complications / pathology*
  • Reoperation
  • Retrospective Studies
  • Rhinitis / diagnosis
  • Rhinitis / pathology*
  • Rhinitis / surgery
  • Rhinoplasty
  • Sinusitis / diagnosis
  • Sinusitis / pathology*
  • Sinusitis / surgery