The Effect of Cag A-Positive Helicobacter Pylori Infection on Vascular Risk Factors and the Development of Ischemic Stroke

Background: Chronic Helicobacter pylori infections are associated with higher risk of ischemic stroke. Cytotoxin-associated gene-A (CagA)-positive H pylori strains may enhance the atherosclerotic process by inducing persistent, low-grade inflammatory response in the arterial wall intima. The aim of this study is to investigate the role of CagA-positive H pylori infection as a risk factor in ischemic stroke and the relation of this infection to vascular risk factors including homocysteine. We also assessed the relation of CagA-positive H pylori infection to the mean internal carotid artery stenosis. Materials and Methods: Ninety patients with ischemic stroke and 60 control subjects were included in this study. Sera were examined for H pylori antibodies and for CagA IgG by ELISA. CagA gene was detected in histopathological samples by polymerase chain reaction (PCR). The levels of cholesterol, fibrinogen, homocysteine and carotid artery stenosis were also assessed. Results: H pylori infection was significantly higher in patients versus controls, 77.8% and 53.3% respectively (P = 0.002). CagA seropositivity was also significantly higher in patients versus controls (P = 0.001). Although CagA-positive H pylori infection was associated with higher risk of ischemic stroke than CagA-negative, no significant difference was detected. However, infection with CagA-positive H pylori was associated with significantly higher levels of cholesterol, fibrinogen, homocysteine and carotid artery stenosis. Conclusion: This study revealed that CagA-positive H pylori infection is a significant risk factor for ischemic stroke and carotid artery stenosis. The association of CagA-negative H pylori infection with ischemic stroke cannot be excluded.