Markers of endothelial cell activation and injury in childhood haemolytic uraemic syndrome

Diarrhoea-associated haemolytic uraemic syndrome (D+ HUS) is usually caused by verotoxin-producing Escherichia coli. Histology shows endothelial swell ing with localised thrombus. Activation of coagulation and fibrinolysis als o occurs. These facts, combined with the knowledge that recovery usually fo llows within weeks, led us to hypothesise that verotoxin causes localised e ndothelial cell activation but not injury. Markers of endothelial cell acti vation and injury were measured serially in 30 children with acute D+ HUS, healthy children, and children receiving chronic dialysis. Interpretation o f markers was complicated by the renal dysfunction characteristic of D+ HUS . Nevertheless there was no evidence for endothelial cell injury, as solubl e tissue factor levels were not increased and soluble thrombomodulin levels were lower than dialysed controls (P < 0.001). In the acute phase, soluble vascular cell adhesion molecule levels were raised above normal (P < 0.001 ), but were lower than dialysed controls (P < 0.001), and soluble E-selecti n levels were not significantly increased compared with normal controls (P = 0.2). Hence, there was no evidence for endothelial cell damage or endothe lial cell activation by the time children reached hospital; but this study did not exclude the possibility that endothelial cell activation occurred p rior to hospital admission.