Markers of endothelial cell activation and immune activation are increased in patients with severe leptospirosis and associated with disease severity

Summary Objectives Previous studies concluded that haemorrhage is one of the most accurate prognostic factors of mortality in leptospirosis. Therefore, endothelial cell activation was investigated in relation to disease severity in severe leptospirosis. Methods Prospective cohort study of severe leptospirosis patients. Plasma levels of sE-selectin and Von Willebrand factor (VWF) were determined. Consequently, an in vitro endothelial cell model was used to assess endothelial activation after exposure to virulent Leptospira . Finally, immune activation, as a potential contributing factor to endothelial cell activation, was determined by soluble IL2-receptor (sIL-2r) and soluble Fas-ligand (sFasL) levels. Results Plasma levels of sE-selectin and VWF strongly increased in patients compared to healthy controls. Furthermore, sE-selectin was significantly elevated (203 ng/ml vs. 157 ng/ml, p