title: The expression of dendritic cell subsets in severe chronic rhinosinusitis with nasal polyps is altered.
abstract: BACKGROUND
  Chronic rhinosinusitis with nasal polyps (CRSwNP) is characterized as a Th2-driven disease. Activated dendritic cells (DCs) are the main T-cell activators; their role in the chronic inflammatory process of nasal polyposis is still unclear.
  
  
  METHODS
  The regulation of DC subsets was analyzed in nasal polyp tissue from CRSwNP patients and compared to inferior turbinate tissue from healthy subjects. Tissue localization and expression of both plasmacytoid and myeloid DCs were assayed by means of immunohistochemistry and flow cytometry. Plasmacytoid DCs were also assayed by PCR, and tissue homogenates were assayed for various inflammatory markers.
  
  
  RESULTS
  The number of plasmacytoid (pDCs) and myeloid (mDCs) dendritic cells was significantly increased in nasal polyp tissue when compared to non-inflamed nasal mucosa. The number of pDCs, but not mDCs, was down-regulated in more severe cases (nasal polyps with asthma) and varied with the cytokine milieu. The amount of pDCs was significantly decreased in IL5+IFNγ - nasal polyp tissue compared to tissues with high IFNγ levels (IL5+IFNγ+). Furthermore, levels of indoleamine 2,3-dioxygenase were increased in nasal polyp compared to inferior turbinate tissue and correlated negatively with the number of pDCs.
  
  
  CONCLUSIONS
  There is an altered balance of pDC and mDC numbers in nasal polyp tissue. pDCs seem to be more susceptible to an inflammatory cytokine milieu and may play a crucial role in disease severity.
authors.affiliation: Upper Airway Research Laboratory (URL), Department of Otorhinolaryngology, Ghent University Hospital, Ghent University, Belgium; Department of Otolaryngology-Head and Neck Surgery, Federal University of São Paulo, Brazil. Electronic address: pezatobau@ig.com.br.
authors.forename: Rogério
authors.initials: R
authors.lastname: Pezato
authors.affiliation: Upper Airway Research Laboratory (URL), Department of Otorhinolaryngology, Ghent University Hospital, Ghent University, Belgium.
authors.forename: Claudina A
authors.initials: CA
authors.lastname: Pérez-Novo
authors.affiliation: Upper Airway Research Laboratory (URL), Department of Otorhinolaryngology, Ghent University Hospital, Ghent University, Belgium.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Holtappels
authors.affiliation: Upper Airway Research Laboratory (URL), Department of Otorhinolaryngology, Ghent University Hospital, Ghent University, Belgium.
authors.forename: Natalie
authors.initials: N
authors.lastname: De Ruyck
authors.affiliation: Upper Airway Research Laboratory (URL), Department of Otorhinolaryngology, Ghent University Hospital, Ghent University, Belgium.
authors.forename: Koen
authors.initials: K
authors.lastname: Van Crombruggen
authors.affiliation: Department of Otorhinolaryngology, AZ ST Lucas Hospital, Ghent, Belgium.
authors.forename: Geert
authors.initials: G
authors.lastname: De Vos
authors.affiliation: Upper Airway Research Laboratory (URL), Department of Otorhinolaryngology, Ghent University Hospital, Ghent University, Belgium.
authors.forename: Claus
authors.initials: C
authors.lastname: Bachert
authors.affiliation: Upper Airway Research Laboratory (URL), Department of Otorhinolaryngology, Ghent University Hospital, Ghent University, Belgium.
authors.forename: Lara
authors.initials: L
authors.lastname: Derycke
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002908:Chronic Disease; D003713:Dendritic Cells / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009298:Nasal Polyps / Q000150:complications / Q000276:immunology*; D060888:Real-Time Polymerase Chain Reaction; D012220:Rhinitis / Q000150:complications / Q000276:immunology*; D012852:Sinusitis / Q000150:complications / Q000276:immunology*; D055815:Young Adult
keywords: Airway; Antigen-presenting cell; Dendritic cells; Nasal polyps; Sinusitis