Simvastatin suppresses airway IL-17 and upregulates IL-10 in patients with stable COPD

Abstract

BACKGROUND: Statins have immunomodulatory properties that may provide benefi cial eff ects in the treatment of COPD. We investigated whether a statin improves the IL-17/IL-10 imbalance in patients with COPD, as has previously been demonstrated in patients with asthma. METHODS: Th irty patients with stable COPD were recruited to a double-blind, randomized, controlled, crossover trial comparing the eff ect of simvastatin, 20 mg po daily, with that of a matched placebo on sputum infl ammatory markers and airway infl ammation. Each treatment was administered for 4 weeks separated by a 4-week washout period. Th e primary outcome was the presence of T-helper 17 cytokines and indoleamine 2,3-dioxygenase (IDO) in induced sputum. Secondary outcomes included sputum infl ammatory cells, FEV 1, and symptoms using the COPD Assessment Test (CAT). RESULTS: At 4 weeks, there was a significant reduction in sputum IL-17A, IL-22, IL-6, and CXCL8 concentrations (mean difference, 2 16.4 pg/mL, P 5.01; 2 48.6 pg/mL, P