title: Patterns of retention of particulate matter in lung tissues of patients with COPD: potential role in disease progression.
abstract: BACKGROUND
  Particulate matter (PM) is present in lung tissues of smokers and urban dwellers. This study was designed to quantify the burden of PM in different lung tissues of subjects with COPD and determine its relationship to disease severity.
  
  
  METHODS
  Surgical lung tissue samples from nonsmokers (control subjects) were compared with those from smokers with normal spirometry and subjects in the four other categories of the GOLD (Global Initiative for Obstructive Lung Disease) classification of COPD severity using quantitative histologic techniques.
  
  
  RESULTS
  PM was present in the lung parenchyma, blood vessel walls, airways, lymphoid follicles, and alveolar macrophages. The total burden of PM (volume fraction [Vv]) in all tissues of the lung was higher in smokers than nonsmokers (P < .001) and also in smokers with airflow obstruction compared with the smokers with normal spirometry (P < .01). There was an incremental increase in total PM burden with increased COPD severity that peaked in GOLD II and then trended downward in GOLD III and IV COPD. This same pattern of PM retention was also observed in alveolar walls. The total burden of PM in lung tissues correlated with a decline in FEV(1)/FVC as well as pack-years smoking. mRNA expression of fibrinogen (γ chain) correlated with total lung burden of PM and burden of PM in lung parenchyma (r(2) = 0.22, P < .001).
  
  
  CONCLUSIONS
  We conclude that retained PM is widely distributed in lung tissues of subjects with COPD and that cigarette smoke exposure and airflow obstruction are associated with retention of PM in lung tissues. We attribute the downward trend in PM burden in severe COPD to either less deposition and retention or selective removal of PM containing tissues by emphysematous destruction.
authors.affiliation: UBC James Hogg Research Centre, Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Sean H
authors.initials: SH
authors.lastname: Ling
authors.affiliation: UBC James Hogg Research Centre, Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.
authors.forename: John E
authors.initials: JE
authors.lastname: McDonough
authors.affiliation: UBC James Hogg Research Centre, Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.
authors.forename: John V
authors.initials: JV
authors.lastname: Gosselink
authors.affiliation: UBC James Hogg Research Centre, Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.
authors.forename: W Mark
authors.initials: WM
authors.lastname: Elliott
authors.affiliation: UBC James Hogg Research Centre, Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.
authors.forename: Shizu
authors.initials: S
authors.lastname: Hayashi
authors.affiliation: UBC James Hogg Research Centre, Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.
authors.forename: James C
authors.initials: JC
authors.lastname: Hogg
authors.affiliation: UBC James Hogg Research Centre, Heart and Lung Institute, St. Paul's Hospital, University of British Columbia, Vancouver, BC, Canada. Electronic address: stephan.vaneeden@hli.ubc.ca.
authors.forename: Stephan F
authors.initials: SF
authors.lastname: van Eeden
mesh_terms: D000368:Aged; D001707:Biopsy, Needle; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008168:Lung / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000032:analysis*; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000473:pathology* / Q000503:physiopathology*; D012016:Reference Values; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D046509:Tissue Culture Techniques
chemical_list: D052638:Particulate Matter