Helicobacter pylori infection, anti‐cagA antibodies and peptic ulcer: a case–control study in Italy

Abstract

Aim: To evaluate the association between infection with specific strains of Helicobacter pylori and peptic ulcer in patients referred for upper gastrointestinal endoscopy. Methods: One thousand, six hundred and twenty‐six consecutive dyspeptic patients, referred to one Endoscopy Unit in Bologna, Italy, were enrolled. For each participant, a blood sample was obtained for the measurement of distinct immunoglobulin G antibodies against H. pylori lysate and cytotoxin associated gene A (cagA). A case–control study included the whole series: patients diagnosed with duodenal (n=275) or gastric (n=71) ulcer were identified and independently compared with controls with non‐ulcer dyspepsia (n=1280). Results: H. pylori seroprevalence (at least one positive marker) was associated with increasing age, male sex and a diagnosis of peptic ulcer. This association was stronger with duodenal ulcer (multivariate odds ratio (OR), 5.2; 95% confidence interval (CI), 3.5–7.9) than with gastric ulcer (OR, 2.3; 95% CI, 1.2–4.4). Further analyses showed that H. pylori lysate+/cagA− subjects had a moderately increased risk of duodenal (OR, 3.2), but not gastric (OR, 1.1), ulcer. When cagA+ subjects were separately compared with seronegative patients, there was a six‐fold increased risk for duodenal ulcer and a three‐fold increased risk for gastric ulcer. Conclusions: A strong positive association between infection with a cagA+ H. pylori strain and the presence of peptic disease was found. The seroprevalence of anti‐cagA antibodies among patients with non‐ulcer dyspepsia is so high (41%) to preclude its use as a pre‐endoscopic screening test.

The Relationship Between Virulence Factors of Helicobacter pylori and Severity of Gastritis in Infected Patients

“…It has recently become possible to detect antibodies for cagA proteins with ELISA methods [8,26]. Along with isolation of H. pylori, demonstration of cagA positivity with noninvasive methods could be helpful in some patient groups.…”

“…A number of studies in Western countries have confirmed that infection with cagA-positive strains is associated with more severe gastritis and higher prevalence of peptic ulcer and gastric cancer [6,7]. However, studies in Far Eastern countries demonstrate equally high prevalence of cagA-positive strains in patients with peptic ulcer, gastric cancer, and nonulcer dyspepsia and in control subjects [8]. In Turkey, cagA positivity and the clinical outcome of H. pylori infection has been studied.…”

Impact ofLactobacillus reuteriSupplementation on Anti-Helicobacter pyloriLevofloxacin-Based Second-Line Therapy

“…Helicobacter pylori ( H. pylori ), a microaerophilic, gram negative bacterium that colonises the mucous layer of the gastric epithelium, is the causative agent of type B gastritis, peptic ulcer, gastric cancer [1–3], and extradigestive diseases [4]. At least one-third of the world's population is infected with H. pylori .…”

Clinical Usefulness of Virulence Factors of Helicobacter pylori as Predictors of the Outcomes of Infection. What is the Evidence?

“…In one case-control study (27) (Table II) the risk of DU and GU was higher in CagA positive subjects compared with seronegative subjects, but the odds ratio (OR) using both Cohort of health evaluation medical program markers (antibodies against H. pylori and anti-CagA antibodies) was similar. In another case-control study (28), serum CagA positive was higher in peptic ulcer patients than in controls, both groups being infected by H. pylori.…”