SUMMARYThe urea breath test is a non-invasive, simple and safe test which provides excellent accuracy both for the initial diagnosis of Helicobacter pylori infection and for the confirmation of its eradication after treatment. Some studies have found no differences between urea breath test performed under non-fasting conditions. The simplicity, good tolerance and economy of the citric acid test meal probably make its systematic use advisable. The urea breath test protocol may be performed with relatively low doses (<100 mg) of urea: 75 mg or even 50 mg seem to be sufficient. With the most widely used protocol (with citric acid and 75 mg of urea), excellent accuracy is obtained when breath samples are collected as early as 10-15 min after urea ingestion. A unique and generally proposed cut-off level is not possible because it has to be adapted to different factors, such as the test meal, the dose and type of urea, or the pre-/post-treatment setting. Fortunately, because positive and negative urea breath test results tend to cluster outside of the range between 2 and 5&, a change in cut-off value within this range would be expected to have little effect on clinical accuracy of the test.

Summary Even with the currently most effective treatment regimens, about 10–20% of patients will fail to obtain eradication of Helicobacter pylori infection. Therefore, in designing a treatment strategy, we should not focus on the results of primary therapy alone, but also on the final (overall) eradication rate. The choice of second‐line treatment depends on which treatment was used initially, as re‐treatment with the same regimen is not recommended. Therefore, it is not necessary to perform culture after the first eradication failure. Assessment of the sensitivity of H. pylori to antibiotics only after failure of the second treatment is suggested in clinical practice. Different possibilities of empirical treatment have been suggested. After failure of proton pump inhibitor–amoxicillin–clarithromycin, quadruple therapy has generally been used. More recently, replacement of the proton pump inhibitor and the bismuth compound by ranitidine bismuth citrate has also achieved good results. After proton pump inhibitor–amoxicillin–nitroimidazole failure, re‐treatment with proton pump inhibitor–amoxicillin–clarithromycin has been proven to be effective. Finally, first‐line treatment should not combine clarithromycin and metronidazole in the same regimen, because of the problem of resistance to both antibiotics. Recently, rifabutin‐based rescue therapies have been shown to constitute an encouraging strategy for eradication failures, as they are effective against H. pylori strains resistant to antibiotics.

No abstract

Our aim was to review systematically the diagnostic accuracy of the Helicobacter pylori stool antigen test. Bibliographical searches were performed in several electronic databases and abstracts from congresses up to May 2003. Eighty-nine studies (10,858 patients) evaluated the stool antigen test in untreated patients. Mean sensitivity, specificity, positive predictive value and negative predictive value were 91%, 93%, 92% and 87%, respectively. Analysis of the eight studies (1399 patients) in which pretreatment evaluation of the monoclonal stool antigen test was performed showed better (p < .001) results (96%, 97%, 96% and 97%, respectively), with a clearer distinction between positive and negative results. Thirty-nine studies (3147 patients) evaluated the stool antigen test for the confirmation of H. pylori eradication 4-8 weeks after therapy, with accuracies of 86%, 92%, 76% and 93% for mean sensitivity, specificity, positive predictive value and negative predictive value, respectively. Results were similar when a gold standard based on at least two methods was used. Relatively low accuracy was reported in some posttreatment studies with the polyclonal stool antigen test. However, excellent results (p < .001) were achieved in all the six studies evaluating the monoclonal stool antigen test 4-8 weeks posttreatment. Results evaluating the stool antigen test < 4 weeks posttreatment are contradictory. Proton-pump inhibitors seem to affect the accuracy of the stool antigen test. Sensitivity and/or specificity in patients with gastrointestinal bleeding may be suboptimal. The stool antigen test performs well in children. Finally, the stool antigen test seems to be a cost-effective method.

Aim: To perform a meta‐analysis of studies comparing twice daily, one‐week triple therapy with a proton pump inhibitor, clarithromycin (C) and amoxycillin (A) (PCA) vs. those using proton pump inhibitor, clarithromycin and a nitroimidazole (N) (PCN) for H. pylori eradication. Review methods: Selection criteria: Comparative randomized trials of PCA vs. PCN were included. Data sources: PubMed database and abstracts from congresses until September 1999. Statistics: Meta‐analysis was performed combining the Odds Ratios (OR) of the individual studies in a global OR (Peto method) both on an intention‐to‐treat (ITT) and on a per protocol (PP) basis. Results: Twenty‐two studies fulfilled the inclusion criteria. Eighteen studies reported ITT and 20 PP analysis. Mean H. pylori eradication rates were 81% (95% CI: 79–83%) ITT, and 84% (82–86%) PP with PCA, and 81% (78–83%) ITT and 84% (82–86%) PP with PCN; the odds ratio for the effect of PCA vs. PCN was 1 (0.83–1.22) on an ITT, and 0.98 (0.8–1.2) on a PP basis. Subanalysis showed that mean H. pylori eradication efficacy with PC(250 b.d.)A was 81% (78–85%) ITT, vs. 86% (83–89%) with PC(250 b.d.)N. The odds ratio for this comparison was 0.68 (0.48–0.98). Finally, when comparing PC(500 b.d.)A against PC(250 b.d.)N ITT cure rates were 77% (74–80%), and 75% (72–78%) with an odds ratio of 1.18 (0.93–1.5). Conclusion: Overall, one‐week combination regimens of PCA and PCN present similar H. pylori eradication efficacy. Nevertheless, the PCN regimen obtains significantly better results when using low doses of C (250 mg b.d.).