A 34-year-old non-smoker man has progressive exertional dyspnea. His father died of emphysema at age 45 and also had chronic liver disease. Spirometry shows obstruction with reduced DLCO. HRCT shows basal-predominant panacinar emphysema. Which investigation confirms the diagnosis?

• A Exhaled nitric oxide measurement
• B Bronchoalveolar lavage fluid analysis
• C Serum angiotensin converting enzyme level
• D Serum alpha-1 antitrypsin level with phenotyping ✓

Explanation

Basal panacinar emphysema in a young non-smoker with family history of early emphysema and liver disease is classic for homozygous PiZZ alpha-1 antitrypsin deficiency. Diagnosis requires a low serum AAT level followed by phenotyping or genotyping to confirm the ZZ genotype. DLCO is reduced because of alveolar capillary bed destruction, and FEV1/FVC falls only after significant loss of parenchyma.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.