title: Cellular composition of induced sputum in healthy adults.
abstract: OBJECTIVE
  To establish reference values for cellularity in induced sputum samples collected from healthy adults.
  
  
  METHODS
  Induced sputum samples were obtained from 88 healthy adult never-smokers (39 males). The mean age was 36 years (range, 18-68 years). The participants had been residing in the city of Florianópolis, Brazil (a medium-sized non-industrial city) for at least two years. After the samples had been processed, we obtained total and differential cell counts.
  
  
  RESULTS
  The mean total cell count was 4.8 ± 4.2 × 10(6) cells/g. There was a predominance of macrophages (mean, 77.5 ± 14.7%) and neutrophils (mean, 23.4 ± 14.3%). Eosinophils were virtually absent (mean, 0.1 ± 0.3%). Lymphocytes and bronchial epithelial cells were scarce. Neither age nor atopy had any effect on the total or differential cell counts.
  
  
  CONCLUSIONS
  In the induced sputum of this healthy adult population, macrophages and neutrophils predominated. However, the proportion of neutrophils was lower than that reported in previous studies, which suggests that reference values might vary depending on geographic location.
authors.affiliation: Federal University of Santa Catarina, Florianópolis, Brazil.
authors.forename: Tiago Neves
authors.initials: TN
authors.lastname: Veras
authors.forename: Emilio
authors.initials: E
authors.lastname: Pizzichini
authors.forename: Leila John Marques
authors.initials: LJ
authors.lastname: Steidle
authors.forename: Cristiane Cinara
authors.initials: CC
authors.lastname: Rocha
authors.forename: Pablo
authors.initials: P
authors.lastname: Moritz
authors.forename: Márcia Margarete Menezes
authors.initials: MM
authors.lastname: Pizzichini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008264:Macrophages / Q000166:cytology; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000166:cytology; D012016:Reference Values; D012907:Smoking; D013183:Sputum / Q000166:cytology*; D014505:Urban Population; D055815:Young Adult