Emphysema is associated with deficiency of which of the following: September 2011
**Core Concept**
Emphysema is a type of chronic obstructive pulmonary disease (COPD) characterized by the destruction of alveolar walls, leading to air trapping and impaired gas exchange. This condition is primarily caused by chronic inflammation and damage to the lung tissue, particularly in the alveoli.
**Why the Correct Answer is Right**
The correct answer is associated with the deficiency of an enzyme that protects the lung tissue from oxidative damage. **Alpha-1 antitrypsin (A1AT)** is a serine protease inhibitor produced in the liver that protects the lung tissue from the enzyme neutrophil elastase. In individuals with emphysema, a deficiency of A1AT leads to uncontrolled activity of neutrophil elastase, resulting in the destruction of lung tissue and the characteristic symptoms of emphysema.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because emphysema is not primarily caused by a deficiency of alpha-1 antichymotrypsin, another serine protease inhibitor. While it may have some role in protecting the lung tissue, it is not the primary enzyme involved in the pathogenesis of emphysema.
* **Option B:** This option is incorrect because emphysema is not primarily caused by a deficiency of alpha-1 antiprotease, which is another name for alpha-1 antitrypsin. The correct term is alpha-1 antitrypsin, not antiprotease.
* **Option C:** This option is incorrect because emphysema is not primarily caused by a deficiency of alpha-1 globulin, which is a type of protein in the blood. Alpha-1 globulin is not directly involved in the pathogenesis of emphysema.
**Clinical Pearl / High-Yield Fact**
A deficiency of alpha-1 antitrypsin can lead to a range of symptoms beyond emphysema, including liver disease and lung disease. It is essential to diagnose and treat A1AT deficiency early to prevent progression to severe lung disease.
**Correct Answer: A. Alpha-1 antitrypsin deficiency.**