Anti-inflammatory Effects of Tiotropium in Patients with Stable COPD

Rationale: Acetylcholine is the primary parasympathetic neurotransmitter in the airways, and induces bronchoconstriction. Since the cholinergic tone appears to be the major reversible component of obstruction, muscarinic receptor antagonism and bronchodilation represent the primary goal of anticholinergic therapy in patients with chronic obstructive pulmonary disease (COPD). Long-acting anticholinergic therapy is central in GOLD stage B-D, because of improvements in lung function, quality of life, and especially reduction of exacerbations. The elicited reduction in exacerbations with the long-acting muscarinic antagonist (LAMA) tiotropium appears larger than that of the long-acting beta agonist (LABA) salmeterol even when the bronchodilation is similar. In asthma too, it has been shown that the addition of the tiotropium to inhaled corticosteroids (ICS)+LABA combination therapy reduces the number of severe exacerbations. These effects on exacerbation frequency suggest that tiotropium might exert anti-inflammatory effects in the airways next to bronchodilatory effects. There are multiple animal and in vivo studies to indeed suggest an anti-inflammatory effect of anticholinergics. Such an anti-inflammatory effect of anticholinergic intervention could be clinically relevant; however it has not been previously demonstrated in patients with COPD. The investigators hypothesize that tiotropium bromide reduces the ongoing inflammation in patients with COPD compared to placebo. The investigators expect a decrease of TNF-alpha mRNA in sputum after treatment with tiotropium bromide. Objective: This research proposal aims to assess the anti-inflammatory effects after 6 weeks treatment with tiotropium compared to placebo in patients with stable COPD. Study design: This will be a multicenter parallel design randomized controlled double-blinded study. Study population: A total of 50 COPD patients with stable disease status will be included and followed for two consecutive visits. Intervention: COPD patients will be randomized to the treatment group (tiotropium respimat 5 ug) or to the placebo group. Main study parameters/endpoints: A decrease of TNF-alpha mRNA in induced sputum will be the main parameter for assessing the anti-inflammatory effects of 6 week treatment with tiotropium in patients with stable COPD. Additionally, changes in sputum cell differentials and other cytokine parameters (protein, mRNA,LTB4), blood cell differentials, CRP, and cytokine parameters, health related quality of life (CCQ, CAT) will be assessed as well as changes in post-bronchdilator FEV1.