The relationship between chronic H. pylori infection, CagA seropositivity and stroke: meta-analysis

AIMS: There is contrasting evidence on the relevance of chronic infection by Helicobacter pylori (H. pylori) as a risk factor for stroke. We performed a meta-analysis of case-control studies to assess association of H. pylori infection and more virulent H. pylori strains, bearing the cytotoxin-associated gene-A (CagA) antigen, with different types of stroke. METHODS: Outcome measures were: H. pylori and CagA seroprevalence in (1) patients with stroke versus controls, and (2) patients with stroke due to large vessel stroke versus patients with other types of stroke and controls. RESULTS: Seven cross-sectional, case-control studies were included. Odds ratio for individual case-control studies and pooled OR for the association between H. pylori seropositivity and stroke was 1.49 (95% CI 1.24-1.81), for the association between stroke and anti-CagA positivity was 2.23 (95% CI 1.49-3.36). Patients with large vessel stroke had higher odds for H. pylori infection than patients with other types of stroke (odds ratio 1.65; 95% CI 1.12-2.45), and than controls (odds ratio 1.61; 95% CI 1.13-2.32). CONCLUSIONS: Association between H. pylori positivity, anti-CagA positivity and stroke is modest and seems higher with stroke due to large vessel disease. This meta-analysis suggests that the role of CagA positive H. pylori strains in different stroke etiologic subclasses should be the target of future prospective investigation

Cryoglobulinemia in hepatitis C virus chronic active hepatitis: Effects of interferon-alpha therapy

We investigated the prevalence of mixed cryoglobulinemia (MC) in 100 cases of chronic hepatitis C virus (HCV) infection and the effect of a 6-month treatment with interferon-alpha (IFN-alpha). Cryoglobulins were detected on admission in 36 of 100 patients and appeared during observation in a further 18 cases. Cryocrit ranged from 0.5% to 20%. Patients with MC were older and had a higher incidence of cirrhosis than those without MC. Immunologic characterization of the cryoprecipitate showed the presence of type II in 84% of cases and type III in 16%. The patients received IFN-alpha (6 MU three times per week) for 6 months. Fifty-seven were responders (i.e., reached normal aminotransferase levels), 26 of these relapsed within 2 months after IFN withdrawal, and 30 did not relapse. After IFN-alpha treatment, cryoglobulinemia disappeared in 11 of the 21 evaluable responders, but in none of the 15 nonresponder patients (p lt 0.003). The clearance of MC was associated in all cases with clearance of HCV RNA. The delayed appearance of cryoglobulinemia in responders seems to be associated with a higher probability of relapse