TY - JOUR T1 - Role of activated complement in COPD exacerbation recovery JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P3606 AU - Alex Mackay AU - John-Paul Westwood AU - Gavin Donaldson AU - Richa Singh AU - Samuel Machin AU - Marie Scully AU - Jadwiga Wedzicha Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P3606.abstract N2 - INTRODUCTIONActivated complement components C3a and C5a are potent inflammatory mediators, and may be responsible for excess inflammation in COPD. We hypothesised that changes in C3a and C5a at exacerbation relate to recovery time.METHODSPaired sera and sputa were prospectively collected from 24 COPD patients when stable and at exacerbation. C3a and C5a levels were measured using Cytometric Bead Array.RESULTSAt exacerbation, median serum C3a was significantly lower than baseline, 113.9 (IQR 56.8-144.7) vs 153.7 ng/ml (102.3-206.1), p<0.001. Median serum C5a levels were also significantly lower at exacerbation than baseline, 12.3 (5.4-34.5) vs 14.8ng/ml (8.3-32.4), p=0.028. Conversely, sputum levels of both C3a and C5a were higher at exacerbation than at baseline: median C3a 15.4 (1.5-30.8) vs 9.1ng/ml (0.5-50.7), p=0.043; median C5a 1.2 (0-7.5) vs 0.3ng/ml (0-2.4), p<0.001.A significant association was seen between change in sputum C5a level from baseline to exacerbation, and recovery time: a greater increase in sputum C5a was associated with a longer clinical recovery (r=0.533, p=0.015).The difference in sputum C3a from baseline to exacerbation was also significantly correlated with recovery (r=0.449, p=0.047).CONCLUSIONSChanges in complement activation at exacerbation relate to recovery length. Excess complement activation may be harmful. Future studies should examine complement inhibition as a potential new therapy for COPD exacerbations. ER -