Helicobacter Pylori Infection Causes Persistent Platelet Activation In Vivo Through Enhanced Lipid Peroxidation

Abstract
Objective— We aimed at investigating the relationship between Helicobacter pylori infection and in vivo lipid peroxidation and platelet activation, as reflected by urinary 8-iso-prostaglandin (PG)F and 11-dehydro-thromboxane (TX)B 2 , respectively, in otherwise healthy dyspeptic subjects. Methods and Results— We measured urinary 8-iso-PGF and 11-dehydro-TXB 2 excretion in 40 dyspeptic subjects with a positive 13 C-urea breath test and 38 dyspeptic individuals with a negative test. Moreover, we investigated the effects of H pylori eradication on prostanoid metabolite excretion in 23 H pylori –positive subjects. We also measured prostanoid metabolite excretion before and after selective cyclooxygenase-2 inhibition with rofecoxib in 4 H pylori– positive subjects. Urinary 8-iso-PGF and 11-dehydro-TXB 2 excretion was significantly higher in the H pylori– positive individuals than in controls. A significant direct correlation was found between the degree of positivity to the 13 C-urea breath test and urinary 8-iso-PGF excretion. The latter was linearly correlated with urinary 11-dehydro-TXB 2 . Successful eradication of H pylori infection led to a significant reduction in both 8-iso-PGF and 11-dehydro-TXB 2 . Furthermore, their levels were unaffected after treatment with rofecoxib. Conclusions— Our study provides evidence of enhanced in vivo lipid peroxidation and platelet activation in association with H pylori infection and suggests a novel mechanism by which an infectious agent could contribute to atherothrombosis.