The Contribution of Small Airway Obstruction to the Pathogenesis of Chronic Obstructive Pulmonary Disease.
The hypothesis that the small conducting airways were the major site of obstruction to airflow in normal lungs was introduced by Rohrer in 1915 and prevailed until Weibel introduced a quantitative method of studying lung anatomy in 1963. Green repeated Rohrer's calculations using Weibels new data in 1965 and found that the smaller conducting airways offered very little resistance to airflow. This conflict was resolved by seminal experiments conducted by Macklem and Mead in 1967, which confirmed that a small proportion of the total lower airways resistance is attributable to small airways <2 mm in diameter. Shortly thereafter, Hogg, Macklem, and Thurlbeck used this technique to show that small airways become the major site of obstruction in lungs affected by emphysema. These and other observations led Mead to write a seminal editorial in 1970 that postulated the small airways are a silent zone within normal lungs where disease can accumulate over many years without being noticed. This review provides a progress report since the 1970s on methods for detecting chronic obstructive pulmonary disease, the structural nature of small airways' disease, and the cellular and molecular mechanisms that are thought to underlie its pathogenesis.
Centre for Heart Lung Innovation, St Paul's Hospital, University of British Columbia (UBC), British Columbia, Canada; Department of Pathology and Laboratory Medicine, UBC, British Columbia, Canada; Respiratory Division, Department of Medicine, UBC, British Columbia, Canada; and Department of Anesthesiology, Pharmacology and Therapeutics, UBC, British Columbia, Canada.
James C
JC
Hogg
Centre for Heart Lung Innovation, St Paul's Hospital, University of British Columbia (UBC), British Columbia, Canada; Department of Pathology and Laboratory Medicine, UBC, British Columbia, Canada; Respiratory Division, Department of Medicine, UBC, British Columbia, Canada; and Department of Anesthesiology, Pharmacology and Therapeutics, UBC, British Columbia, Canada.
Peter D
PD
Paré
Centre for Heart Lung Innovation, St Paul's Hospital, University of British Columbia (UBC), British Columbia, Canada; Department of Pathology and Laboratory Medicine, UBC, British Columbia, Canada; Respiratory Division, Department of Medicine, UBC, British Columbia, Canada; and Department of Anesthesiology, Pharmacology and Therapeutics, UBC, British Columbia, Canada.
Tillie-Louise
TL
Hackett
D000402:Airway Obstruction / Q000150:complications*; D000818:Animals; D042241:Early Diagnosis; D006801:Humans; D008168:Lung / Q000473:pathology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000209:etiology*; D011656:Pulmonary Emphysema / Q000150:complications*; D014057:Tomography, X-Ray Computed / Q000379:methods