Review Question - QID 100884

The patient is suffering from emphysema caused by his genetic disorder, a1-antitrypsin deficiency. This condition can be worsened by smoking-mediated increased release of elastase from macrophages and neutrophils.

a1-antitrypsin is crucial in inactivating elastase, a protease secreted by macrophages and neutrophils. Therefore, the absence of alpha1-antitrypsin leads to an imbalance between proteases and antiproteases, essentially leaving the actions of elastase unchecked. Elastase destroys alveolar walls, leading to several hallmarks of emphysema: increased compliance, decreased radial traction, and air-trapping.

Hunter et al. discuss how treatment of chronic obstructive pulmonary disease (COPD) should begin with smoking cessation. Pharmaceutical treatments of benefit in COPD include ß2 agonists, corticosteroids, and anticholinergics.

Stoller et al. note that a1-antitrypsin deficiency leads to the presentation of emphysema earlier in life. Because of the deficiency, the lung is not protected from destruction by elastase. The authors cite infusions of a1-antitrypsin as a form of therapy.

Illustration A depicts histological findings seen in emphysema. Note the destruction of alveolar walls that has led to the enlarged airways pictured. Illustration B depicts the role smoking plays in the pathogenesis of emphysema. Illustration C depicts a normal CXR. Illustration D depicts a CXR of a patient with a1-antitrypsin deficiency. Note the hyperinflated lungs compared to the normal CXR (Illustration D), the hyperlucent lungs, the flattened diaphragm, and the area devoid of lung markings in the right middle lobe of the lung possibly due to bullous formation.

Incorrect Answers:
Answer 1: Major basic protein is secreted by eosinophils.
Answer 2: Antibodies (secreted by B-cells) against type IV collagen is seen with Goodpasture syndrome.
Answer 3: Mucus is produced by mucous glands in the submucosa as well as by goblet cells.
Answer 4: Surfactant is produced by type II pneumocytes.