title: Differential lymphocyte infiltration in small airways and lung parenchyma in COPD patients.
abstract: BACKGROUND
  In COPD, although histological lesions at both the small airways (wall thickening and tissue remodeling) and lung parenchyma (emphysematous destruction) are definitely different, the inflammatory cells involved in both processes are the same. Our study aims to determine if these histopathological phenotypes are related to two different lymphocyte profiles.
  
  
  METHODS
  Distribution and cell density of CD3(+), CD4(+), CD8(+) and B lymphocytes were compared in small airways and parenchymal interstitium of 9 non-smokers, 18 smokers without COPD, 16 smokers with moderate COPD and 16 patients with very severe COPD undergoing lung transplantation. Spatial distribution of lymphocytes in periemphysematous parenchyma was also assessed.
  
  
  RESULTS
  CD3(+) and B cell densities were significantly higher in small airways than parenchyma interstitium of very severe COPD patients. Furthermore, CD8(+) cells were increased in the epithelium of airways of moderate COPD patients compared to non-smokers. Although CD8(+) cell density was increased in parenchyma of COPD patients, CD8(+) and B cell densities were similar when comparing periemphysematous and non-emphysematous alveolar interstitium.
  
  
  CONCLUSIONS
  In COPD, it is true that the small airways' wall shows a clear inflammatory pattern, with a high mononuclear infiltration and tissue remodeling. However, parenchymal interstitium shows a milder CD8(+) infiltration which, moreover, is not spatially related to emphysematous destroyed areas.
authors.affiliation: Departament de Biologia Cel-lular, Universitat de Barcelona, Barcelona, Spain. jordiog82@gmail.com
authors.forename: Jordi
authors.initials: J
authors.lastname: Olloquequi
authors.forename: Jaume
authors.initials: J
authors.lastname: Ferrer
authors.forename: Juan F
authors.initials: JF
authors.lastname: Montes
authors.forename: Esther
authors.initials: E
authors.lastname: Rodríguez
authors.forename: M Angeles
authors.initials: MA
authors.lastname: Montero
authors.forename: José
authors.initials: J
authors.lastname: García-Valero
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology*; D005260:Female; D006801:Humans; D008168:Lung / Q000276:immunology / Q000473:pathology*; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000276:immunology / Q000473:pathology*; D012907:Smoking / Q000276:immunology / Q000473:pathology