Review Question - QID 100890

This patient most likely has centriacinar emphysema. Enlarged airspaces can be seen on CT, contributing to the diagnosis. IgA does not play a role in the development of emphysema.

Emphysema is characterized by dilated airspaces with increased compliance. Centriacinar (centrilobular) emphysema is caused by dilation of the bronchioles but not the alveoli and is most common because it is tightly associated with smoking. It tends to localize to upper lobes. By contrast, panacinar (panlobular) emphysema dilates alveoli as well, and occurs most often in the lower lobes where blood flow is greatest. It is also exacerbated by smoking.

Hunter and King review management of COPD (emphysema is one cause of obstruction in COPD, along with chronic bronchitis). Acute exacerbations leading to hospitalization should be treated with inhaled beta-2 agonists and anticholinergics, oxygen, systemic corticosteroids and antibiotics. Influenza and pneumococcal vaccines are indicated for prevention of exacerbation in this population.

Finlay et al. performed brochoalveolar lavage in patients with emphysema compared to age- and smoking-history matched controls and found that levels of matrix metalloproteinases (MMPs) were significantly greater in patients with emphysema. They suggest that presence of high MMPs might be more effective for diagnosis of emphysema than elastase.

Image A demonstrates a CT scan showing centriacinar emphysema. Widened air spaces are present throughout the lung. Illustration A is a gross pathology sample demonstrating centriacinar emphysema.

Incorrect Answers:
Answer 2- 5: All of the above items are normally implicated in the pathogenesis of emphysema through their functions in lung parenchymal breakdown or remodeling.