Hyaluronic acid in COPD exacerbations of different etiology

Abstract

Respiratory infections have been implicated as a risk factor for acute exacerbations of COPD (AECOPD). Hyaluronic acid (HA) is associated with COPD severity and outcome. We aimed to evaluate serum levels of HA at AECOPD of different etiology. Serum HA was measured by ELISA, in the PREVENT study, an investigator-initiated and driven, controlled trial, with 450 COPD patients, GOLD II-IV, followed for 3 years. From 2833 visits, we included AECOPD visits without infection in the last stable visit (n=102) and categorised them according to etiology; no new infection (n=22); viral infections (n=23); bacterial infections (n=37); viral and bacterial infections (n=20). Multiplex PCR was used to monitor viral infections in laryngopharyngeal swabs and microbiological analysis was performed in sputum samples. HA levels were significantly higher at AECOPD as compared to previous stable visits (p=0.007) and to follow-up visits (p=0.003). At AECOPD, highest levels of HA (ng/ml, median IQR) were observed in cases with no viral infections [144.1 (117.5-175.3)] and lowest levels in cases with bacterial infections [114.4 (101.8-135.4)]. At stable visits highest levels of HA were observed in cases with viral infection at ΑECOPD [128.02 (104.6-148.3)] and lowest levels of HA in cases with viral and bacterial infections at AECOPD [119.0 (101.4-138.5)]. Mixed linear regression models showed that HA levels were positively associated with MMRC score (p The results of our study indicate that serum levels of HA are associated to the etiology of respiratory infections at AECOPD.