Airway and systemic inflammation are features of chronic obstructive pulmonary disease (COPD) and there is growing interest in clarifying the inflammatory processes. Strenuous exercise induces an intensified systemic inflammatory response in patients with COPD, but no study has investigated the airway inflammatory and anti-inflammatory responses to exercise.

Twenty steroid-naïve, ex-smokers, with diagnosed COPD (FEV(1)=66±12%) underwent baseline collection of venous blood and induced sputum followed by an incremental exercise test to symptom limitation 48-hours later. Additional venous blood samples were collected following exercise at 0, 2 and 24-hours, while induced sputum was collected 2 and 24-hours after exercise. Sputum and blood samples were analyzed for differential cell count, CD4(+) and CD8(+) T-lymphocytes (serum only), interleukin (IL)-6, IL-8, IL-10, CCL5, and high sensitivity C-reactive protein (serum only).

There was an increase in the number of sputum eosinophils (cells/gram, p=0.012) and a reduction in sputum IL-6 (p=0.01) 24-hours post exercise. Sputum IL-8 and CCL5 were also persistently decreased after exercise (p=0.0098 and p=0.0012, respectively) but sputum IL-10 did not change. There was a decrease in serum eosinophils 2-hours after exercise (p=0.0014) and a reduction in serum CCL5 immediately following and 2-hours post exercise (p<0.0001). Both serum eosinophils and CCL5 returned to baseline-levels within 24-hours.

An acute bout of exercise resulted in a significant increase in the number of sputum eosinophils which may be mediated by serum CCL5. However, there was also a reduction in sputum pro-inflammatory cytokines, suggesting some anti-inflammatory effect of exercise in the lungs of steroid-naïve patients with COPD.