A 35-year-old man comes to the office due to worsening shortness of breath. The patient is an avid hiker; he began to have shortness of breath 18 months ago on challenging hikes, but it now occurs even while he is walking. He has also had mild wheezing and sputum production recently. The patient takes an antihistamine as needed without much improvement. He has no other medical problems. The patient has smoked half a pack of cigarettes daily for the past 5 years. His father died from lung and liver disease at a young age. Spirometry shows decreased forced expiratory volume in 1 second (FEV1), decreased forced vital capacity (FVC), and a decreased FEV1/FVC ratio. This patient's lower lung lobes are most likely to demonstrate which of the following findings?

Question

A 35-year-old man comes to the office due to worsening shortness of breath.  The patient is an avid hiker; he began to have shortness of breath 18 months ago on challenging hikes, but it now occurs even while he is walking.  He has also had mild wheezing and sputum production recently.  The patient takes an antihistamine as needed without much improvement.  He has no other medical problems.  The patient has smoked half a pack of cigarettes daily for the past 5 years.  His father died from lung and liver disease at a young age.  Spirometry shows decreased forced expiratory volume in 1 second (FEV1), decreased forced vital capacity (FVC), and a decreased FEV1/FVC ratio.  This patient's lower lung lobes are most likely to demonstrate which of the following findings?

Quizplus · Accepted Answer

11ec160b_3a03_5187_9249_a7ddb9e81b57_MD0001_00 This patient with chronic progressive dyspnea has spirometry findings (reduced forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] ratio) that are consistent with obstructive lung disease. His young age and family history of lung and liver disease suggest emphysema due to alpha-1 antitrypsin deficiency. The diagnosis is further suggested by his minimal smoking history; chronic obstructive pulmonary disease due to tobacco exposure alone is most commonly seen in those with a >30-pack-year smoking history. Alpha-1 antitrypsin is the major inhibitor of neutrophil elastase, and deficiency leads to unchecked elastase-mediated tissue damage in the lungs. Because alpha-1 antitrypsin is deficient throughout the acinus, the entirety of the acinus is affected, resulting in panacinar emphysema. The lower lung lobes are predominantly affected, likely due to relatively greater perfusion compared to the upper lung lobes, allowing for an increased rate of neutrophil infiltration. (Choice A) Centriacinar emphysema is characteristic of tobacco-related emphysema, as only the portion of the acinus most exposed to smoke particles is affected. Tobacco-related centriacinar emphysema predominantly affects the upper lung lobes, possibly due to a higher ventilation-perfusion ratio in those regions. (Choice B) Colonization of the lung with pathogenic bacteria most commonly occurs in patients with cystic fibrosis and is not a common feature of alpha-1 antitrypsin deficiency. (Choice C) Compensatory hyperinflation refers to the expansion of normal lung parenchyma that occurs when adjacent lung segments or lobes collapse or are surgically removed. (Choice E) Subpleural blebs can develop in severe emphysema but typically occur in the apices, rather than the bases, of the lung. Their rupture is a cause of spontaneous pneumothorax. Educational objective: Alpha-1 antitrypsin is the major serum inhibitor of neutrophil elastase. Alpha-1 antitrypsin deficiency typically causes early-onset panacinar emphysema, predominantly affecting the lower lung lobes. __________ References: Alpha-1 antitrypsin deficiency: a commonly overlooked cause of lung disease. (http://www.ncbi.nlm.nih.gov/pubmed/22761482) Alpha-1 antitrypsin deficiency. (http://www.ncbi.nlm.nih.gov/pubmed/20303723)

A 35-Year-Old Man Comes to the Office Due to Worsening