PROSTACYCLIN PRODUCTION AND VITAMIN E IN THE HEMOLYTIC UREMIC SYNDROME

Abstract

Preliminary reports suggest that Hemolytic Uremic Syndrome (HUS) plasma is unable to stimulate endothelial cells to produce normal amounts of prostacyclin (PGI2), a substance known to inhibit platelet aggregation and thrombosis. Some children with HUS have been reported to have low levels of Vitamin E. Neonatal plasma reportedly is unable to stimulate normal PGI2 production. This can be corrected by the in vitro addition of Vitamin E. We, therefore, tested the hypothesis that HUS sera have an impaired ability to stimulate PGI2 production and that this abnormality is associated with Vitamin E deficiency. HUS (n=19) and normal children sera (n=22) were incubated with cultured endothelial cells, and PGI2 generation was determined by radioimmunoassay of its stable metabolite, 6-keto PGF1α. Vitamin E and total lipids were also measured in HUS (n=15) and normal sera (n=19). The following results (mean ± SD) were obtained: Sera from children with HUS residing in the Intermountain Region have a significantly (p<0.001) decreased ability to stimulate PGI2 production by cultured endothelial cells. However, the lack of significant difference in the Vitamin E and Vitamin E/Total Lipids ratios fails to support a role for Vitamin E in the pathogenesis of HUS.