Effect of pulmonary rehabilitation (PR) on inflammation status in patients with COPD

hysical activity and exercise training have been proven to be an essential component of PR for COPD. However, the effects of exercise on systemic inflammation in COPD are controversial, and physical activity as a part of PR has not been clearly shown to modify inflammation. Objective: to assess changes of different inflammatory markers in response to both an incremental (CET) and constant load (CLET) exercise test, and to a period of training as part of PR. Methods: 32 patients with severe COPD were evaluated 6 weeks before (T0), at the beginning (T1) and at the end (T2) of PR. The evaluation included: dyspnea, health-related quality of life by Saint George's Respiratory Questionnaire (SGRQ), six minute walking test (6MWT), CET and CLET. Moreover, a pattern of 27 different cytokines and chemokines were also evaluated in the serum samples by Multiplex analysis and, in 10 patients, also in sputum samples. Results: PR significantly improved dyspnea (MRC p<0.01, TDI +3.4±3), SGRQ (p<0.05), 6MWT (p< 0.01), leg endurance time (p<0.001 ). No significant difference was observed in the serum level of cytokines or chemokines either after CET or CLET, or after the period of PR. After PR, a significant increase in IL-6, IL-13, EOTAXIN, FGF, G-CSF, IP-10, RANTES and MIP-1 b (P<0.05 for all) was observed in the sputum samples. Conclusion: No significant serum inflammatory response associated with exercise or after training could be observed. The significant increase of certain cytokines and chemokines in the sputum, suggests that training could induce a local production of pro-inflammatory mediators which does not translate into systemic increase. The relevance of this observation needs to be further clarified.