title: Perspectives on the etiology of chronic rhinosinusitis.
abstract: OBJECTIVE
  This article reviews recent insights surrounding the etiology and pathogenesis of chronic rhinosinusitis. In particular, we highlight the increasing recognition of host-mediated mechanisms in driving mucosal inflammation.
  
  
  RESULTS
  Published differences between epithelium from patients with chronic rhinosinusitis and normal controls can be classified into several broad categories. Alterations are reported in the various components of the epithelial innate immune system including epithelial-expressed pattern-recognition receptors (PRRs) and the levels of antimicrobial innate immune effector molecules. Other studies demonstrate differences in the proteins involved in maintaining epithelial barrier integrity. Finally, recent studies show in chronic rhinosinusitis that epithelial-derived cytokines, chemokines and inducible surface proteins are involved in recruiting and activating cells of the adaptive immune system.
  
  
  CONCLUSIONS
  The sinonasal epithelium provides a mechanical and innate immune barrier to a diverse array of environmental agents. This barrier also plays a key role in regulating the acquired mucosal immune response in the nose. Recent studies suggest that defects in this barrier may foster development of chronic sinonasal inflammation in response to environmental agents, and pathogenic or commensal organisms. The ability to dissect and analyze defects in the inflammatory response in rhinosinusitis may help identify novel targets for drug development.
authors: Department of Otolaryngology, Head and Neck Surgery, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA.
authors: Bruce K
authors: BK
authors: Tan
authors: Robert P
authors: RP
authors: Schleimer
authors: Robert C
authors: RC
authors: Kern
mesh_terms: D000528:Alternaria / Q000302:isolation & purification; D001402:B-Lymphocytes / Q000276:immunology; D002908:Chronic Disease; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology; D009079:Mucociliary Clearance / Q000276:immunology; D009181:Mycoses / Q000150:complications; D009297:Nasal Mucosa / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D044462:Receptors, Proteinase-Activated / Q000276:immunology; D012220:Rhinitis / Q000276:immunology / Q000382:microbiology* / Q000473:pathology; D013203:Staphylococcal Infections / Q000150:complications; D013211:Staphylococcus aureus / Q000302:isolation & purification
chemical_list: D044462:Receptors, Proteinase-Activated