Background: The non-selective phosphodiesterase inhibitor theophylline has bronchodilator/anti-inflammatory properties and is widely used in the treatment of airways diseases. We determined the effect of long-term theophylline treatment on airway inflammation in patients with chronic obstructive pulmonary disease (COPD).
Populations and methods: Seventeen stable COPD patients were enrolled in the 12-month study. Theophylline was administered at 400mg/day. We studied changes in symptoms, spirometry, sputum volume, and sputum inflammatory cytokines levels. We also examined the effects of theophylline on the release of inflammatory cytokines in vitro by measuring interleukin (IL)-8 and tumor necrosis factor (TNF)-alpha levels from lipopolysaccharide (LPS)-stimulated neutrophils and THP-1 cells.
Results: Forced vital capacity was increased and sputum IL-8 levels decreased after 4 weeks of theophylline treatment. After 6 months of theophylline treatment, forced expiratory volume in 1s was increased, and neutrophils counts and TNF-alpha levels in sputum were reduced. Levels of IL-8 and TNF-alpha released by LPS-stimulated THP-1 cells were reduced by treatment with theophylline at 10microg/ml. In contrast, IL-8 levels released by LPS-stimulated neutrophils were reduced by treatment with theophylline at 100microg/ml.
Conclusion: Our clinical study of small population showed that long-term treatment with theophylline seems to reduce airway inflammation in stable COPD patients.