Late -breaking abstract: The Guangzhou COPD exacerbation study: Relationship of exacerbations "th viral infections and soluble biomarkers

In the Chinese city of Guangzhou a cohort of around 200 COPD patients (around n= 50 of GOLD stage 0,1,2 and 3/4) and around 50 age-matched controls were recruited to participate in an open observational study for 2 years (from 2010-2012) to evaluate the occurrence and frequency of exacerbations and their association with environmental factors such as air pollution, humidity and temperature and viral and bacterial infections. Environmental factors were obtained on a daily basis and patient symptoms were monitored daily using a Blackberry tool (EXACT-PRO). In the 2 year follow up period the patients had to attend the clinic at regular fixed intervals (visits 2 (0 months), 3 (12 months) and 4 (24 months)) for baseline measures as well as unscheduled extra visits due to an exacerbation. At all visits functional measurements were made and blood, sputum, nasal and throat specimens collected for microbiological and biomarker analyses. All sputum samples collected at visits 2, 3 and 4 and extra visits were analyzed for different biomarkers. Preliminary results indicate that: A) a large proportion of exacerbations are associated with detection of respiratory viruses, human rhinovirus being the most common B) at an exacerbation COPD patients showed significantly elevated sputum levels of a range of cytokines and chemokines including interleukin-1beta, interleukin 6, CXCL10, CXCL11 and interferon gamma (IFNg), compared to control levels C) CXCL10, CXCL11 in sputum and serum, and IFNg in sputum, were raised specifically during exacerbations associated with a detection of a respiratory virus. The same proteins were not increased when viruses were detected during stable disease.