A 48-year-old man has gradually increasing dyspnea and a 4-kg weight loss over the past 2 years. He has smoked two packs of cigarettes per day for 20 years, but not for the past year. Physical examination shows an increase in the an- teroposterior diameter of the chest. Auscultation of the chest shows decreased breath sounds. A chest radiograph shows bilateral hyperlucent lungs; the lucency is especially marked in the upper lobes. Pulmonary function tests show that FEV is markedly decreased, but FVC is normal, and the FEV1/FVC ratio is decreased. Which of the following is most likely to con- tribute to the pathogenesis of his disease? A B C D E Release of elastase from neutrophils