title: Small airway remodeling in idiopathic interstitial pneumonias: a pathological study.
abstract: BACKGROUND
  Few studies have addressed small airway (SA) histopathological changes and their possible role in the remodeling process in idiopathic interstitial pneumonias.
  
  
  OBJECTIVE
  To study morphological, morphometrical and immunohistochemical features of SA in idiopathic pulmonary fibrosis (usual interstitial pneumonia, UIP) and nonspecific interstitial pneumonia (NSIP).
  
  
  METHODS
  We analyzed SA pathology in lung biopsies from 29 patients with UIP and 8 with NSIP. Biopsies were compared with lung tissue from 13 patients with constrictive bronchiolitis (CB) as positive controls and 10 normal autopsied control lungs. We semi-quantitatively analyzed SA structure, inflammation, architectural features and the bronchiolar epithelial immunohistochemical expression of TGF-beta, MMP-2, 7, 9, and their tissue inhibitors (TIMP-1, 2).
  
  
  RESULTS
  Compared to controls, patients with UIP, NSIP and CB presented increased bronchiolar inflammation, peribronchiolar inflammation and fibrosis and decreased luminal areas. UIP patients had thicker walls due to an increase in most airway compartments. NSIP patients presented increased epithelial areas, whereas patients with CB had larger inner wall areas. All of the groups studied presented increased bronchiolar expression of MMP-7 and MMP-9, compared to the controls.
  
  
  CONCLUSIONS
  We conclude that SAs are pathologically altered and may take part in the lung-remodeling process in idiopathic interstitial pneumonias.
authors.affiliation: Pathology Department, Hospital das Clinicas, University of Sao Paulo Medical School, São Paulo, Brazil.
authors.forename: George Castro
authors.initials: GC
authors.lastname: Figueira de Mello
authors.forename: Carlos Roberto
authors.initials: CR
authors.lastname: Ribeiro Carvalho
authors.forename: Ronaldo
authors.initials: R
authors.lastname: Adib Kairalla
authors.forename: Paulo Hilário
authors.initials: PH
authors.lastname: Nascimento Saldiva
authors.forename: Sandra
authors.initials: S
authors.lastname: Fernezlian
authors.forename: Luiz Fernando
authors.initials: LF
authors.lastname: Ferraz Silva
authors.forename: Marisa
authors.initials: M
authors.lastname: Dolhnikoff
authors.forename: Thais
authors.initials: T
authors.lastname: Mauad
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D055745:Bronchioles / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D054988:Idiopathic Interstitial Pneumonias / Q000378:metabolism / Q000473:pathology*; D007150:Immunohistochemistry; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism*; D008875:Middle Aged; D019714:Tissue Inhibitor of Metalloproteinases / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000378:metabolism*
chemical_list: D019714:Tissue Inhibitor of Metalloproteinases; D016212:Transforming Growth Factor beta; D020782:Matrix Metalloproteinases