International Journal of COPD (Feb 2021)
The Impact of Muscarinic Receptor Antagonists on Airway Inflammation: A Systematic Review
Abstract
Luigino Calzetta,1 Angelo Coppola,2 Beatrice Ludovica Ritondo,3 Matteo Matino,3 Alfredo Chetta,1 Paola Rogliani2,3 1Department of Medicine and Surgery, Respiratory Disease and Lung Function Unit, University of Parma, Parma, Italy; 2Division of Respiratory Medicine, University Hospital “Policlinico Tor Vergata”, Rome, Italy; 3Unit of Respiratory Medicine, Department of Experimental Medicine, University of Rome “Tor Vergata”, Rome, ItalyCorrespondence: Paola Rogliani Department of Experimental MedicineUniversity of Rome “Tor Vergata”, Via Montpellier 1, Rome 00133, ItalyTel +39 06 2090 4656Email [email protected]: Long-acting muscarinic receptor antagonists (LAMAs) are the cornerstone for the treatment of chronic obstructive pulmonary disease (COPD); furthermore, tiotropium is approved as add-on therapy in severe asthmatic patients. Accumulating evidence suggests that LAMAs may modulate airway contractility and airway hyperresponsiveness not only by blocking muscarinic acetylcholine receptors (mAchRs) expressed on airway smooth muscle but also via anti-inflammatory mechanisms by blocking mAchRs expressed on inflammatory cells, submucosal glands, and epithelial cells. The aim of this systematic review, performed according to the PRISMA-P guidelines, was to provide a synthesis of the literature on the anti-inflammatory impact of muscarinic receptor antagonists in the airways. Most of the current evidence originates from studies on tiotropium, that demonstrated a reduction in synthesis and release of cytokines and chemokines, as well as the number of total and differential inflammatory cells, induced by different pro-inflammatory stimuli. Conversely, few data are currently available for aclidinium and glycopyrronium, whereas no studies on the potential anti-inflammatory effect of umeclidinium have been reported. Overall, a large body of evidence supports the beneficial impact of tiotropium against airway inflammation. Further well-designed randomized controlled trials are needed to better elucidate the anti-inflammatory mechanisms leading to the protective effect of LAMAs against exacerbations via identifying suitable biomarkers.Keywords: muscarinic receptor antagonist, LAMA, tiotropium, inflammation, systematic review
