ABSTRACT
Chronic obstructive pulmonary disease (COPD) is a public health problem worldwide, being a major cause of chronic morbidity and mortality. The World Health Organization (WHO) estimates COPD is currently the fourth leading cause of death in the world, and further increases in its prevalence and mortality can be predicted in the coming decades (1). According to the most recent guidelines, COPD is defined as a disease state characterized by not fully reversible airflow limitation that is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases (1). A number of studies in the past demonstrated that a chronic inflammation is present throughout the airways, parenchyma, and pulmonary vasculature in patients with COPD and that this inflammatory response has an important role in the development of chronic airflow limitation (2-4). The recognition that inflammatory cells play a key role in the pathogenesis of COPD is now so widespread that, for the first time, it has led to the inclusion of the terms ‘‘abnormal inflammatory response’’ in the disease definition.
