title: Lysozyme expression is increased in the sinus mucosa of patients with chronic rhinosinusitis.
abstract: BACKGROUND
  The presence of fungi and bacteria in the paranasal sinuses may contribute to ongoing inflammation. Lysozyme is an innate immune peptide with bactericidal and fungicidal activity. The expression of lysozyme in chronic rhinosinusitis (CRS) is poorly understood and deficiencies in lysozyme expression may contribute to the ongoing inflammation in CRS patients.
  
  
  OBJECTIVE
  Determine lysozyme expression in sinus mucosa of normal and CRS patients with (CRSwNP) and without (CRSsNP) nasal polyps.
  
  
  METHODS
  Sinus mucosa specimens (n = 82) were processed for standard histology, immunohistochemical localisation of lysozyme, immunofluorescent localisation of fungi, and qPCR analysis of lysozyme expression.
  
  
  RESULTS
  CRS specimens displayed high-levels of lysozyme immunoreactivity in many of the abundant serous cells. Moderate levels were detected in some epithelial cells and inflammatory cells. Low levels were detected in some subepithelial glands of control specimens. No difference in immunoreactivity was detected between CRSwNP and CRSsNP specimens. Fungal elements were not visualised in any sinus specimen. qPCR analysis demonstrated variable lysozyme expression between individuals.
  
  
  CONCLUSIONS
  Lysozyme protein expression is increased in patients with CRS, suggesting a defect in lysozyme expression is not responsible for the microbial colonisation often associated with CRS. The functional activity of lysozyme in CRS patients needs to be further investigated.
authors.affiliation: Flinders ENT Department of Surgery, Flinders Medical Centre and Flinders University, Adelaide, Australia.
authors.forename: C M
authors.initials: CM
authors.lastname: Woods
authors.forename: V S
authors.initials: VS
authors.lastname: Lee
authors.forename: D J
authors.initials: DJ
authors.lastname: Hussey
authors.forename: S
authors.initials: S
authors.lastname: Irandoust
authors.forename: E H
authors.initials: EH
authors.lastname: Ooi
authors.forename: L W
authors.initials: LW
authors.lastname: Tan
authors.forename: A S
authors.initials: AS
authors.lastname: Carney
mesh_terms: D023181:Antimicrobial Cationic Peptides / Q000378:metabolism; D002908:Chronic Disease; D006801:Humans; D007150:Immunohistochemistry; D009092:Mucous Membrane / Q000378:metabolism; D009113:Muramidase / Q000378:metabolism*; D010256:Paranasal Sinuses / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D012220:Rhinitis / Q000276:immunology / Q000378:metabolism*; D012852:Sinusitis / Q000276:immunology / Q000378:metabolism*
chemical_list: D023181:Antimicrobial Cationic Peptides; D009113:Muramidase