title: Reproducibility of nasal lavage in the context of the inhalation challenge investigation of occupational rhinitis.
abstract: BACKGROUND
  The nasal lavage (NAL) method is increasingly used to assess changes in upper airways inflammation in the investigation of occupational rhinitis (OR). A good reproducibility of the method is fundamental to accurately assess changes in markers of inflammation in nasal secretions before and after inhalation challenges. The main objective of this study was to assess the short-term reproducibility of cells and cellular markers of inflammation in NAL in the setting of specific inhalation challenge (SIC) investigating OR. An ancillary objective was to assess the reproducibility of NAL in the context of two different SIC methodologies.
  
  
  METHODS
  Twenty-five subjects attended the laboratory for 2 separate days of NAL performed within the same week. On the first visit subjects underwent NAL before a SIC sham session and on the second visit before a SIC with the active agent. These prechallenge NAL measurements obtained on both days were used to analyze the reproducibility of the NAL method.
  
  
  RESULTS
  The reproducibility for cell differential counts was satisfactory for neutrophils (intraclass correlation coefficient [ICC] = 0.68), for eosinophils (ICC = 0.95), for macrophages (ICC = 0.77), and for epithelial cells (ICC = 0.73). The reproducibility of total cell counting was poor (ICC = 0.12). The reproducibility of ECP concentrations was satisfactory (ICC = 0.67). Eosinophil counts were reproducible in the context of two different challenge methodologies.
  
  
  CONCLUSIONS
  The NAL method was shown to be sufficiently reproducible to be considered useful for the monitoring of upper airways inflammation during the investigation of OR by SIC.
authors.affiliation: Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Montreal, Quebec, Canada. roberto.castano@mail.mcgill.ca
authors.forename: Roberto
authors.initials: R
authors.lastname: Castano
authors.forename: Gilles
authors.initials: G
authors.lastname: Thériault
authors.forename: Karim
authors.initials: K
authors.lastname: Maghni
authors.forename: Heberto
authors.initials: H
authors.lastname: Ghezzo
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Malo
authors.forename: Denyse
authors.initials: D
authors.lastname: Gautrin
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational / Q000009:adverse effects*; D002452:Cell Count; D047150:Eosinophil Cationic Protein / Q000378:metabolism; D004804:Eosinophils / Q000473:pathology; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D006801:Humans; D001239:Inhalation; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity; D017817:Nasal Lavage Fluid / Q000737:chemistry / Q000166:cytology; D009784:Occupational Diseases / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D016273:Occupational Exposure / Q000009:adverse effects; D015203:Reproducibility of Results; D012220:Rhinitis / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D007507:Therapeutic Irrigation / Q000379:methods*
chemical_list: D000395:Air Pollutants, Occupational; D047150:Eosinophil Cationic Protein