Risk of Infectious Diseases in Patients with COPD

In this paper, we review data on the risk of infectious diseases in chronic obstructive pulmonary disease (COPD), including the efficacy of antibiotics for prevention and treatment of acute COPD exacerbations, with a focus on more recent studies. Studies indicate that immunological mechanisms in COPD are impaired, leading to increased susceptibility to infection. Exacerbations are often infectious in origin (viral and/or bacterial) although pathogens may also be present in the lungs of person with stable COPD. The detailed mechanisms of exacerbations remain under investigation. Despite great variations in design and operational definitions of outcome, studies consistently find that patients with COPD are at an increased risk of respiratory infections. Patients with COPD do not appear to be at an increased risk of infections outside the respiratory system, but only a small number of studies have addressed this. The role of antibiotics in the management of acute exacerbations of COPD is disputed. However, findings from recent studies suggest that antibiotics are effective, although primarily in patients admitted to the hospital, thus representing patients with more severe exacerbations. Still, the question of antibiotic efficacy for different clinically well-defined subgroups of COPD exacerbation as well as the choice of the most appropriate antibiotic for these subgroups is uncertain. Antibiotics may also be efficacious in exacerbation prevention. Recent studies on the efficacy of macrolides for the prevention of COPD exacerbations demonstrated promising results. Nevertheless, questions on the risk-benefit ratio of macrolides, efficacy in subgroups of COPD patients, and long-term effects remain unanswered.