Is the inflammatory response of the lungs in COPD abnormal?

The current defi nition of COPD includes the statement that “the airfl ow limitation is usually progressive and associated with an abnormal infl ammatory response of the lungs to noxious particles or gases, primarily caused by cigarette smoking.” 1 The term “abnormal infl ammatory response” was fi rst introduced in the defi nition of COPD in the 2001 GOLD (Global Initiative for Chronic Obstructive Lung Disease) article, 2 and since then the same phrase has been used in the defi nition of the disease. Even in a recent article in CHEST (February 2011) by van den Berge and colleagues 3 on small airways disease, the same term was used in the COPD defi nition. This letter aims to challenge the word “abnormal” and to propose its omission from the defi nition of the disease in the future. New evidence related to COPD pathogenesis has emerged to support the thought that the lungs respond against cigarette smoke in a rather normal or common way of self-defending. 4 6