Published December 23, 2014
A study by researchers at the University at Buffalo with the U.S. Department of Veterans Affairs shows that patients with chronic, obstructive pulmonary disease (COPD), experience more respiratory symptoms when their lungs are ‘colonized’ by bacteria, even in the absence of an acute exacerbation.
The paper was published as an article in press in the Annals of the American Thoracic Society.
Jingjing Yin, PhD, is currently an assistant professor at department of biostatistics in the Jiann-Ping Hsu College of Public Health at Georgia Southern University worked on the study with University at Buffalo researchers. Yin earned her doctorate degree from the University at Buffalo’s School of Public Health and Health Professions with a concentration in biostatistics.
COPD, which is most commonly caused by smoking and includes chronic bronchitis and emphysema, compromises the lungs’ innate defense against bacteria, allowing bacteria to persist.
In previous work, these UB researchers illustrated that having bacteria in the lungs in COPD is associated with increased inflammation. This study takes the next step by proving that such bacterial colonization is sufficient to trigger clinically significant increases in shortness of breath, cough and sputum in COPD patients.
Several unique features of this study helped the investigators make this important observation: It is the first longitudinal study of symptoms in COPD during bacterial colonization with a well-validated tool for assessing symptoms; it also controlled for variables, such as local air pollution levels and weather-related factors, such as humidity, which can affect daily symptoms in these patients.
Findings demonstrate that it’s time for a paradigm shift in how patients with stable COPD are treated. The lungs are constantly being exposed to microbes ‘with every breath you take’ as well as from aspiration of small amounts of secretions from the throat, especially during sleep. If the persistence of these bacteria contributes to increased symptoms and inflammation in the lungs in stable COPD, we should regard this as a chronic infection, not innocuous colonization. For that reason, more must be done to reduce chronic infections in COPD.
“Research support from the Buffalo Veterans Affairs (VA) and participation of patients was absolutely critical. We can model inflammation and other effects of smoking using animals but documenting respiratory symptoms can only be done with human subjects,” stated researcher Sanjay Sethi, PhD. “We could not have done this study without the generous participation of our patients.”
Co-authors on the study include: Sanjay Sethi, senior author, UB professor of medicine and division chief of pulmonary, critical care and sleep medicine, director of the COPD Study Clinic and staff physician at the Veterans Affairs Western New York Healthcare System (Buffalo VA); Timothy F Murphy, PhD, SUNY Distinguished Professor and senior associate dean; Himanshu Desai, PhD, previously a UB fellow in pulmonary and critical care medicine; Aarti Aggarwal, PhD, previously a UB fellow in infectious disease; Karen Eschberger, RN, of the Buffalo VA; G. Iyer Parameswaran, PhD, UB research assistant professor of medicine and infectious diseases physician at the Buffalo VA; Catherine Wrona and Lori Grove, UB research technicians and Brydon Grant, PhD, UB professor of medicine and now pulmonologist at the Fayetteville VA Medical Center. The study was funded by the U.S. Department of Veterans Affairs.