P134 POLYMICROBIAL AIRWAY COLONISATION AND SYSTEMIC INFLAMMATION IN STABLE COPD

J. J. P. Goldring, G. C. Donaldson, J. K. Quint, R. Baghai-Ravary, A. R. C. Patel, J. A. Wedzicha. Academic Unit of Respiratory Medicine, University College London Medical School, London, UK

Introduction The presence of lower airway bacteria in stable state chronic obstructive pulmonary disease (COPD) is associated with a heightened inflammatory response.1 In most cases, only a single potentially pathogenic microbe (PPM) is isolated but about 20% of patients will have co-colonisation with two PPMs. We hypothesised that the magnitude of inflammation would differ according to the number of PPMs present.

Methods Patients with COPD who had been followed in our cohort for >1 year were sampled at 6-monthly baseline visits. Patients were symptomatically stable at these visits and had not had an exacerbation or antibiotic use in the preceding 6 weeks. Serum was taken for the acute phase response mediators interleukin 6 (IL6) and C-reactive protein (CRP) and spontaneously expectorated sputum was collected for standard microbiological culture. To ensure that the samples reflected the stable state, they were subsequently excluded from analysis if an exacerbation occurred within 2 weeks of the visit. Salivary sputum (>25 epithelial cells/low power field) was also excluded.

Results There were 196 patients with 479 sputum samples (47% 0 PPM, 42% 1 PPM, 11% 2 PPM). Their mean age was 68.0 years (SD 8.1); 61% were male; forced expiratory volume in 1 s 47.1 (18.3)% predicted and 49.8 (36.7) pack-years smoking history.

Conclusions CRP was significantly higher in dual versus single PPM airway colonisation in the stable state and this may be related to bacterial load (table 1). Dual pathogen colonisation may have a contributory role in the pathogenesis of systemic complications and declining lung function, both of which have been linked to elevated systemic inflammatory markers.

P135 ASSESSMENT OF OSTEOPOROSIS RISK IN PATIENTS WITH COPD: A COMMUNITY-BASED STUDY

Y. Shanshal, E. L. Wooff, M. …