Association Between Plasma Glycocalyx Component Levels and Poor Prognosis in Influenza Type A (H1N1)

Background: Influenza A virus infection causes a series of diseases, but the factors associated with disease severity are not fully understood. Disruption of the endothelial glycocalyx contributes to acute lung injury in sepsis, but has not been well studied in H1N1 influenza. We aim to determine whether the plasma glycocalyx components levels are predictive of disease severity in H1N1 influenza.Methods: This prospective observational study included 53 patients with influenza A (H1N1), who were admitted to the Pulmonary and Critical Care Medicine and Intensive Care Unit, and 30 healthy controls between November 2017 and March 2019 in our hospital. Patients were grouped by severity and survival. We collected clinical data and blood samples at admission. Inflammatory factors (tumor necrosis factor-α, interleukin-6, interleukin-10) and endothelial glycocalyx components (syndecan-1, hyaluronan, heparan sulfate) were measured.Results: The plasma levels of syndecan-1, hyaluronan, and heparan sulfate were significantly higher in patients with severe influenza A (H1N1) than in mild cases. At a cutoff point >81.0 ng/mL, syndecan-1 had a 92.1% sensitivity and 86.7% specificity for diagnosing severe H1N1. Syndecan-1 and hyaluronan were positively correlated with disease severity, which was indicated by the APACHE II and SOFA scores and lactate levels, and negatively correlated with albumin levels. Non-survivors had higher syndecan-1 levels than did survivors, and syndecan-1 was strongly predictive of 28-day mortality (area under the curve, 0.855).Conclusions: An increased plasma syndecan-1 level was an independent risk factor for mortality and may be indicative of disease severity in patients with influenza A (H1N1).Trial registration: CHINA, ChiCTR2000040921. Retrospectively registered