Inflammation in COPD: pathogenesis, local and systemic effects

COPD is a disease characterized by inflammation both in its stable phase and during exacerbations. Inflammation is present in the respiratory compartment, the inflammatory cells and different mediators of inflammation being present. Studies have shown that some mediators of inflammation have a high level at systemic level also, inducing a certain grade of systemic inflammation, mainly responsible for the systemic manifestation of the disease. It seems that the both local and the systemic inflammation are amplified during exacerbations. The purpose of this paper is to review the respiratory inflammatory reaction, to identify the main actors involved in the stable phase of the disease and during exacerbations, the systemic inflammation accompanying the local inflammation, and to find the possible interrelations between the systemic and local inflammation, on one hand, and the respiratory and extra-respiratory manifestations of COPD on the other hand. The understanding of the pathogenic mechanisms, which stay at the base of inflammation and of the possible interrelations shown, represents a theoretical interest and also a practical one, concerning the targets of different therapeutic agents which could be used in the management and in the control of the disease.