Cellular Infiltrates in Asthma and in Chronic Obstructive Pulmonary Disease

Abstract

Introduction According to current definitions, chronic bronchitis is a disease with cough and expectorations for at least 3 months during 2 consecutive yr, and asthma is a disease with reversible airway obstruction. The definitions point out a smooth muscle-related disease in asthma and a mucousand bronchialgland-associated disease in chronic bronchitis. Very little is known of the morphologic aspects of the airways at the early stages of either disease.So far, both asthma and chronic bronchitis have been defined mainly by clinical observations and respiratory function measurements. However, these lead only to rough definitions of the diseases and leave open the pathophysiologic mechanisms. Classic dogma equates asthma with mucousplugging,bronchialsmooth musclehyperplasia, eosinophilia, and thickening of the epithelial basement membrane. However, these characteristics are those seen in autopsy of lungs obtained from asthmatics dying from status asthmaticus. They do not reflect the changes in the early phase of the disease nor do they relate to disease severity. Developments in bronchoscopic and electron microscopic techniques have been essential in obtaining better knowledge of airway morphology in living patients with asthma, chronic bronchitis, or emphysema.