IS CHRONIC OBSTRUCTIVE PULMONARY DISEASE AN INFLAMMATORY DISORDER?

Chronic obstructive pulmonary disease (COPD) is a common and increasing condition worldwide and is mainly caused by cigarette smoke. It is defined as an irreversible obstructive airways disease that is preventable and treatable. The latter description implies assumptions that there are components of the pathophysiology and progression of the disease that are amenable to therapeutic intervention. The most attractive option is to determine whether COPD is an inflammatory disorder and which aspects of inflammation can be inhibited with current and potential drugs. This paper reviews the evidence for an inflammatory basis for COPD and the potential interventions. Once established, COPD is progressive and characterised by a neutrophilic inflammation of the airways, even after smoke exposure ceases. Further, there is upregulation of pro-inflammatory cytokines that are chemotactic for neutrophils and their activation. The ensuing destruction of the respiratory tract is mediated by activation of several proteolytic mechanisms that are able to overcome antiproteolytic defences. Investigation continues to explain the weak effects of corticosteroids in this condition, and the observation that there is inhibition of histone deacetylase is plausible. There appears to be a genetic predisposition for the development of severe COPD.