Association between cerebral ischemia and cytotoxin-associated gene-A-bearing strains of Helicobacter pylori.

BACKGROUND AND PURPOSE: Studies on Helicobacter pylori infection and risk of ischemic stroke yielded variable results. Infection with more virulent H. pylori strains, such as cytotoxin-associated gene-A (CagA)-bearing strains, may be of particular relevance for ischemic diseases. We investigated whether H. pylori and CagA seropositivity are independent risk factors for cerebral ischemia or its etiologic subtypes.

METHODS: We determined IgG antibodies against H. pylori and CagA protein (enzyme immunoassays) in 190 patients with acute cerebral ischemia and in 229 age- and sex-matched control subjects selected randomly from the general population.

RESULTS: CagA seropositivity was more common in patients (114/190; 60.0%) than in control subjects (99/229; 43.2%; odds ratio, 1.97; 95% CI, 1.33 to 2.91; P<0.001). This result remained significant after adjustment for age, sex, vascular risk factors and diseases, and childhood and adult social status (odds ratio, 1.84; 95% CI, 1.13 to 3.00; P=0.015). Subgroup analyses yielded similar results in all etiologic stroke subtypes. In contrast, H. pylori seropositivity in general was not associated with increased risk of stroke or its etiologic subtypes.

CONCLUSIONS: Our results support the hypothesis of an association between infection with CagA-positive H. pylori strains and acute cerebral ischemia.