title: Differential distribution of inflammatory cells in large and small airways in smokers.
abstract: BACKGROUND
  Smoking induces structural changes in the airways, and is considered a major factor in the development of airflow obstruction in chronic obstructive pulmonary disease. However, differences in inflammatory cell distribution between large airways (LA) and small airways (SA) have not been systematically explored in smokers.
  
  
  OBJECTIVE
  The content of cells infiltrating the airway wall differs between LA and SA.
  
  
  OBJECTIVE
  To compare the content of neutrophils, macrophages, lymphocytes and mast cells infiltrating LA and SA in smokers who underwent surgery for lung cancer.
  
  
  METHODS
  Lung tissue from 15 smokers was analysed. Inflammatory cells in the lamina propria were identified by immunohistochemical analysis, quantified by digital image analysis and expressed as number of cells per surface area.
  
  
  RESULTS
  The number of neutrophils infiltrating the lamina propria of SA (median 225.3 cells/mm(2)) was higher than that in the lamina propria of LA (median 60.2 cells/mm(2); p<0.001). Similar results were observed for mast cells: 313.3 and 133.7 cells/mm(2) in the SA and LA, respectively (p<0.001). In contrast, the number of CD4 cells was higher in LA compared with SA (median 217.8 vs 80.5 cells/mm(2); p = 0.042).
  
  
  CONCLUSIONS
  These findings indicate a non-uniform distribution of neutrophils and mast cells throughout the bronchial tree, and suggest that these cells may be involved in the development of smoking-related peripheral lung injury.
authors.affiliation: Department of Pulmonology, Leiden University Medical Centre (LUMC), Leiden, The Netherlands.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Battaglia
authors.forename: Thais
authors.initials: T
authors.lastname: Mauad
authors.forename: Annemarie M
authors.initials: AM
authors.lastname: van Schadewijk
authors.forename: Antonia M
authors.initials: AM
authors.lastname: Vignola
authors.forename: Klaus F
authors.initials: KF
authors.lastname: Rabe
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Bellia
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Sterk
authors.forename: Pieter S
authors.initials: PS
authors.lastname: Hiemstra
mesh_terms: D002452:Cell Count; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008168:Lung / Q000276:immunology / Q000473:pathology*; D008175:Lung Neoplasms / Q000276:immunology / Q000473:pathology*; D008214:Lymphocytes / Q000276:immunology*; D008264:Macrophages / Q000276:immunology; D008297:Male; D008407:Mast Cells / Q000276:immunology*; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology; D010586:Phagocytes / Q000276:immunology*; D020545:Respiratory Mucosa / Q000276:immunology / Q000473:pathology; D012907:Smoking / Q000276:immunology / Q000473:pathology*