Abstract
Abnormal diffusing capacity is common in HIV-infected individuals including never smokers. Etiologies for diffusing capacity impairment in HIV are not understood, particularly in those without a history of cigarette smoking.
A cross-sectional analysis of 158 HIV-infected individuals without acute respiratory symptoms or infection to determine associations between a DLCO % predicted and participant demographics, pulmonary spirometric measures (FEV1 and FEV1/FVC), radiographic emphysema (fraction of lung voxels <−950 Hounsfield units), pulmonary vascular/cardiovascular disease (echocardiographic tricuspid regurgitant jet velocity [TRV], N-terminal pro-brain natriuretic peptide), and airway inflammation (induced sputum cell counts), stratified by history of smoking.
Mean DLCO was 65.9% predicted, and 55 (34.8%) participants had a significantly reduced DLCO(<60% predicted). Lower DLCO % predicted in ever smokers was associated with lower post-bronchodilator FEV1 % predicted (p<0.001) and greater radiographic emphysema (p=0.001). In never smokers, mean (standard deviation) DLCO was 72.7% (13.4%) predicted, and DLCO correlated with post-bronchodilator FEV1 (p=0.02), sputum neutrophils (p=0.03), and sputum lymphocytes (p=0.009), but not radiographic emphysema.
Airway obstruction, emphysema, and inflammation influence DLCO in HIV. Never smokers may have a unique phenotype of diffusing capacity impairment. The interaction of multiple factors may account for the pervasive nature of diffusing capacity impairment in HIV infection.
- ERS