Ηeparan sulphate in infectious and non-infectious exacerbations of COPD.

BACKGROUND AND OBJECTIVE: Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are associated with worsening health outcomes and effective treatment of each episode is essential. In this study, we aimed to investigate if plasma levels of heparan sulphate (HS) are associated with the aetiology of AECOPD. METHODS: COPD patients (N = 1189), GOLD grade II-IV, from a discovery cohort (N = 638) and from a validation cohort (N = 551), were included in the study. HS and heparanase (HSPE-1) were measured longitudinally in plasma at stable state, at AECOPD and at 4 weeks follow-up. RESULTS: Plasma HS was higher in patients with COPD as compared with non-COPD controls and was significantly increased at AECOPD as compared to stable state (p < 0.001) in the discovery and in the validation cohorts. Four distinct exacerbation groups were classified based on aetiology (no-infection/bacterial-infection/viral-infection/bacterial and viral coinfection) in the validation cohort. The fold-increase of HS from stable state to AECOPD was associated with the aetiology of exacerbation and was higher in cases with bacterial and viral coinfections. HSPE-1 was also significantly increased at AECOPD, however, there was no association of HSPE-1 levels with the aetiology of these events. The probability of having an infection at AECOPD was raised as HS levels increased from stable state to AECOPD. This probability was higher for bacterial infections than viral infections. CONCLUSION: The results of our study indicate that circulating levels of HS are increased at AECOPD and this increase may be associated with the aetiology of these events.