Chronic Obstructive Pulmonary Disease (COPD) is an inflammatory lung disease that is characterized by a slowly progressive and irreversible deterioration in lung function due to chronic bronchitis or emphysema, resulting in an increased shortness of breath. It is the 12 most prevalent disease world wide and cigarette smoking is the main risk factor for developing the disease - over 90% of patients are cigarette smokers. Exacerbations of COPD can occur due to infection of the lungs with bacteria. Neutrophils are the most abundant cells of the immune system, constituting the primary line of defence against bacterial infection. A process called the respiratory burst generates reactive oxygen species (ROS) which are used along with proteases to kill bacteria. These products are toxic in high concentrations and may cause damage to surrounding lung tissue when released. Infected lungs have an increased number of neutrophils, which have been recruited into the lungs to kill the bacteria. Despite this, large numbers of bacteria are still present, and increased damage to the lungs is evident. Therefore, the neutrophils may not be working efficiently to kill the bacteria in the COPD lung.