title: Central airways remodeling in COPD patients.
abstract: BACKGROUND
  The contribution to airflow obstruction by the remodeling of the peripheral airways in chronic obstructive pulmonary disease (COPD) patients has been well documented, but less is known about the role played by the large airways. Few studies have investigated the presence of histopathological changes due to remodeling in the large airways of COPD patients.
  
  
  OBJECTIVE
  The aim of this study was to verify the presence of airway remodeling in the central airways of COPD patients, quantifying the airway smooth muscle (ASM) area and the extracellular matrix (ECM) protein deposition, both in the subepithelial region and in the ASM, and to verify the possible contribution to airflow obstruction by the above mentioned histopathological changes.
  
  
  METHODS
  Biopsies of segmental bronchi spurs were performed in COPD patients and control smoker subjects and immunostained for collagen type I, versican, decorin, biglycan, and alpha-smooth muscle actin. ECM protein deposition was measured at both subepithelial, and ASM layers.
  
  
  RESULTS
  The staining for collagen I and versican was greater in the subepithelial layer of COPD patients than in control subjects. An inverse correlation was found between collagen I in the subepithelial layer and both forced expiratory volume in 1 second and ratio between forced expiratory volume in 1 second and forced vital capacity. A statistically significant increase of the ASM area was observed in the central airways of COPD patients versus controls.
  
  
  CONCLUSIONS
  These findings indicate that airway remodeling also affects the large airways in COPD patients who have greater deposition of ECM proteins in the subepithelial layer and a larger smooth muscle area than control smoker subjects. These changes may contribute to chronic airflow obstruction in COPD patients.
authors.affiliation: Unit of Respiratory Medicine, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Pini
authors.affiliation: Department of Respiratory Medicine, Spedali Civili di Brescia, Brescia, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Pinelli
authors.affiliation: Unit of Respiratory Medicine, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
authors.forename: Denise
authors.initials: D
authors.lastname: Modina
authors.affiliation: Department Bronchoscopy, Spedali Civili di Brescia, Brescia, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Bezzi
authors.affiliation: Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Tiberio
authors.affiliation: Unit of Respiratory Medicine, Department of Clinical and Experimental Sciences, University of Brescia, Brescia, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Tantucci
mesh_terms: D000199:Actins / Q000032:analysis; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D056151:Airway Remodeling; D001706:Biopsy; D001980:Bronchi / Q000737:chemistry / Q000473:pathology* / Q000503:physiopathology; D016022:Case-Control Studies; D024042:Collagen Type I / Q000032:analysis; D005109:Extracellular Matrix / Q000737:chemistry / Q000473:pathology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000737:chemistry / Q000473:pathology*; D011509:Proteoglycans / Q000032:analysis; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D014797:Vital Capacity
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D024042:Collagen Type I; D011509:Proteoglycans
keywords: COPD; airway smooth muscle; central airways; proteoglycans; remodeling