H Pylori Found Linked to Strokes

A study by Italian researchers has found that certain strains of ulcer-causing Helicobacter pylori are much more prevalent in the blood of patients who have suffered an atherosclerotic stroke. The study was published in the July 8, 2002, rapid access issue of Circulation.

The cytotoxin-associated gene-A (CagA) makes strains of H pylori virulent and especially damaging to large arteries leading to the brain, causing inflammation and further restricting blood flow. The researchers compared different strains of H pylori in the bloodstream of 138 patients with large-vessel stroke (group A), 61 patients with cardioembolic stroke (group B), and 151 healthy volunteers. H pylori infection was about the same in group A and group B. The presence of CagA-positive strains was significantly higher in large-vessel stroke patients than in the cardioembolic stroke group (42.8% vs 19.7%) or the control group (17.9%). Only the CagA-positive strains were associated with ischemic stroke and that association applied only to patients with atherosclerotic stroke.

C-reactive protein (CRP) levels were also higher in both stroke groups, but patients with CagA-positive strains had the highest CRP levels, indicating a more severe inflammatory response. The researchers theorize that the virulent H pylori may increase system-wide infection, which can increase atherosclerosis and contribute to plaque instability. The study was led by Antonio Pietroiusti, M.D., professor of internal medicine at Tor Vergata University in Rome (Italy) and lead author.






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