Association of helicobacter pylori dupA with the failure of primary eradication

To determine whether the presence of dupA Helicobacter pylori (H. pylori) influences the cure rate of primary eradication therapy.

Several virulence factors of H. pylori have been reported to affect the efficacy of the eradication rate. However, no study has investigated whether the presence of dupA affects eradication failure.

The presence of dupA was evaluated in 142 H. pylori strains isolated from 142 patients with gastrointestinal diseases. Of these patients, 104 received primary eradication therapy for 1 week. The risk factors for eradication failure were determined using univariate and multivariate analyses.

Among 142 strains, 44 (31.0%) were dupA positive. There was no association between dupA status and gastroduodenal diseases (P>0.05). The clarithromycin (CLR) resistance rate was generally lower in the dupA-positive than in the dupA-negative group (20.4% vs. 35.7%, P=0.06). However, dupA prevalence was higher in the eradication failure group than in the success group (36.3% vs. 21.9%). Among the CLR-resistant H. pylori infected group, the successful eradication rate was significantly lower in patients infected with dupA-positive H. pylori than dupA-negative H. pylori (P=0.04). In multivariate analysis adjusted for age, sex, and type of disease, not only CLR resistance but also dupA presence was independent risk factors for eradication failure (adjusted odds ratio=3.71; 95% confidence interval,1.07-12.83).

Although CLR resistant was more reliable predictor, the presence of dupA may also be an independent risk factor for eradication failure.