The diffusion capacity of the lung is decreased in all of the following conditions except:

DLCO is increased in Goodpasture's since the basement membrane is damaged, thereby increasing the chances of diffusion of CO across lesser number of anatomical layers. DLCO is decreased in pulmonary aery hypeension since the fibrosis in pulmonary vessels will reduce the diffusion of CO across the anatomical layers. DLCO is decreased in patients with: Interstitial lung disease Emphysema (COPD usually have normal DLCO) Bronchiolitis obliterans Lymphangioleiomyomatosis Pulmonary hypeension Thromboembolic disease DLCO is increased in patients with: Alveolar hemorrhage Congestive hea failure Asthma