Grant: Travel Awards - Institute Community Support

Patients with Chronic Obstructive Pulmonary Disease (COPD) are prone to developing acute exacerbations (AECOPD), defined as periods of severe shortness of breath. AECOPDs often lead to hospitalizations and the economic burden of these hospitalizations on the Canadian healthcare system is approximately $1 billion per year. AECOPD are mostly driven by lung infections and preventing these infections can reduce the frequency of these events. Immunoglobulins (Ig), also known as antibodies, are an important part of the immune system. The main class of immunoglobulins in the human body is IgG, making up 75% of all antibodies in the blood. We hypothesized that COPD patients with lower levels of IgG in their bodies cannot fight off infections properly, leading to increased risk of AECOPDs and COPD hospitalizations. To test this hypothesis, we measured blood IgG levels in 2,267 COPD subjects who were previously enrolled in four studies. We observed that low IgG levels are relatively common among COPD subjects, affecting approximately 1 in 4 patients. Importantly, we found that the risk of COPD hospitalizations was 41% higher in those with decreased IgG levels compared to those with normal IgG levels. Our data support that COPD subjects with lower IgG levels are at increased risk of hospitalizations. By examining blood IgG levels, which can be measured in a quick and cheap laboratory test, clinicians may be able to identify high-risk COPD patients for escalation of treatment and closer clinical monitoring. These measures may prevent AECOPDs and hospitalizations, thereby alleviating an enormous health burden to patients as well as considerable health care costs.