Grant: Travel Awards - Institute Community Support

There are currently no blood tests available for diagnosing acute exacerbations of chronic obstructive pulmonary disease (AECOPD), and the need for having such tests is urgent. Systemic inflammation and mild cardiac dysfunction are often associated with AECOPD. We determined the relationship of AECOPD with selected biomarkers of systemic inflammation and cardiac injury. In 220 patients who were hospitalized for AECOPD as principal diagnosis, we measured plasma C-reactive protein (CRP), pulmonary and activation-regulated chemokine (PARC), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), D-dimer, and troponin I using enzyme-linked immunosorbent assays or RAMP quantitative immunochromatographic assays (Response Biomedical Corp). These biomarkers were assayed at baseline (day 1 of hospitalization), day 3, discharge (approximately a week after admission), day 30, and day 90. Twelve COPD patients, who were stable, served as controls. We have found CRP levels were highest on day 1 (30.1mg/L) and progressively decreased over time (11.5mg/L at time of discharge, 7.1mg/L at day 30, and 7.4mg/L at day 90, p<.0001 for trend) and were significantly higher than the levels for patients with stable COPD (4.2mg/L; p<0.05). NT-proBNP was also highest at day 1 (367.0ng/L) and significantly decreased over time (123.5ng/L at day 30 and 129.5ng/L at day 90; p<0.001) and was significantly greater than in the control group (79.0ng/L; p<0.01). D-dimer, PARC and troponin I, on the other hand, showed no temporal changes during hospitalization and were no different between those patients with AECOPD and those with stable COPD. Among clinically available systemic inflammatory and cardiac biomarkers, only CRP and NT-proBNP levels are significantly elevated during AECOPD and decreased with recovery. Changes in NT-proBNP may suggest transient decompensation of left and/or right ventricles. Together, these proteins are promising biomarkers for diagnosing and tracking AECOPD.