A 36-year-old nonsmoker presents with progressive dyspnea and decreased exercise tolerance over 2 years. Vital signs show BP 128/82, HR 102, RR 24, SpO2 92% on room air. CT chest reveals panacinar emphysema predominantly affecting lower lobes. Laboratory studies show elevated transaminases (AST 68 U/L, ALT 72 U/L) and serum alpha-1 antitrypsin level 57 mg/dL. He denies tobacco or occupational exposures. Which mechanism best explains these findings?
- A)Inactivation of surfactant by plasma proteins
- B)Deposition of ferruginous bodies in the interstitium
- C)Autoimmune destruction of bronchial smooth muscle
- D)Dynein arm defect in respiratory cilia
- E)Unopposed neutrophil elastase activity due to low alpha 1 antitrypsinGABARITO
Explicação
Alpha 1 antitrypsin deficiency removes an important antiprotease defense against neutrophil elastase. Unopposed elastase destroys alveolar walls, causing panacinar emphysema that classically predominates in the lung bases and can occur in younger nonsmokers. M... Ver explicação completa e trilha adaptativa →