title: Chronic rhinosinusitis and cystic fibrosis: the interaction between sinus bacteria and mucosal immunity.
abstract: BACKGROUND
  Chronic rhinosinusitis (CRS) is highly prevalent in cystic fibrosis (CF) patients, in whom a close correlation exists between the microbiology of the upper and lower respiratory tracts. We have reported intramucosal bacterial microcolonies in the sinus mucosa from idiopathic CRS patients and have made observations suggesting that these may result from mucosal immunotolerance secondary to altered macrophage function. In this study, we sought to determine whether intramucosal microcolonies exist in the mucosa of CF patients with CRS, and to investigate the associated mucosal immunology.
  
  
  METHODS
  Mucus swabs and tissue biopsies were taken from 9 patients with CF undergoing functional endoscopic sinus surgery (FESS) for CRS, 11 with idiopathic CRS undergoing FESS, and 9 with normal sinuses having transnasal pituitary surgery. Microbiology samples were taken for culture and intramucosal microcolonies were sought using Gram staining. Mucosal immune cells were identified using fluorescent immunohistochemistry.
  
  
  RESULTS
  Positive culture rates were similar between CRS patients and controls, but there were significantly more intramucosal microcolonies in the CRS groups (8/9 CF-CRS, 7/11 CRS), compared to controls (1/9). Furthermore, the biodensity of intramucosal microcolonies was significantly higher in CF-CRS than idiopathic CRS. Mirroring the microbiological observations, the number of CD163+ macrophages was significantly increased in CF-CRS compared to idiopathic CRS (p = 0.03).
  
  
  CONCLUSIONS
  Intramucosal bacteria exist within the sinus mucosa of patients with CF, and in significantly greater numbers than in idiopathic CRS patients. We speculate that intramucosal microcolonies may also exist in the lower respiratory tract mucosa in CF and play a role in disease recalcitrance.
authors.affiliation: Department of Surgery, The University of Auckland, Auckland, New Zealand.
authors.forename: Raymond J T
authors.initials: RJ
authors.lastname: Kim
authors.affiliation: Department of Surgery, The University of Auckland, Auckland, New Zealand.
authors.forename: Lydia
authors.initials: L
authors.lastname: Park
authors.affiliation: Department of Surgery, The University of Auckland, Auckland, New Zealand.|Maurice Wilkins Centre, The University of Auckland, Auckland, New Zealand.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Wood
authors.affiliation: Department of Surgery, The University of Auckland, Auckland, New Zealand.
authors.forename: Tary
authors.initials: T
authors.lastname: Yin
authors.affiliation: Department of Surgery, The University of Auckland, Auckland, New Zealand.
authors.forename: Ravi
authors.initials: R
authors.lastname: Jain
authors.affiliation: Department of Surgery, The University of Auckland, Auckland, New Zealand.|Maurice Wilkins Centre, The University of Auckland, Auckland, New Zealand.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Douglas
mesh_terms: D000328:Adult; D001402:B-Lymphocytes / Q000276:immunology; D001419:Bacteria / Q000302:isolation & purification; D001431:Bacteriological Techniques; D003550:Cystic Fibrosis / Q000382:microbiology* / Q000473:pathology; D006801:Humans; D018928:Immunity, Mucosal / Q000502:physiology*; D017404:In Situ Hybridization, Fluorescence; D008856:Microscopy, Fluorescence; D009297:Nasal Mucosa / Q000276:immunology / Q000382:microbiology; D010256:Paranasal Sinuses / Q000382:microbiology*; D012220:Rhinitis / Q000382:microbiology*; D012852:Sinusitis / Q000382:microbiology*; D013601:T-Lymphocytes / Q000276:immunology
keywords: CRS; M2; chronic inflammation; chronic rhinosinusitis; cystic fibrosis; host immunity; immunology; intramucosal bacteria; macrophage; microbiology