Efficacy of a therapeutic strategy for eradication of Helicobacter pylori infection

First-line therapies for H. pylori infection in Italy: a pooled-data analysis

Background: Curing H. pylori infection remains challenging, and the use of most effective first-line therapy represents a therapeutic cornerstone. To monitor the efficacy of first-line therapies in Italy, we designed a systematic review with pooled- data analysis of data published in the last 15 years. Methods: The search was focused on standard regimens and adult patients. Studies that included modified therapy regimens, pediatric patients, case series with less than 5 patients, and those in language other than English were excluded. Results: A total of 40 studies, with 74 therapeutic arms and 13,539 patients were evaluated. Among the 14-day triple therapies, the combination with proton pump inhibitor (PPI), clarithromycin and amoxicillin achieved the highest (77.9%) success rate, whilst the lowest success rate (62.7%) was observed following the 14-day PPI, clarithromycin and tinidazole regimen. The overall efficacy of triple therapies significantly decreased from 75.7% to 72.1% in the last decade. Sequential (88.3% on 3431 patients), concomitant (88.8% on 376 patients), and the bismuth-based quadruple therapy with three-in-one capsule, containing bismuth subcitrate potassium (140 mg), metronidazole (125 mg), tetracycline (125 mg) (90.4% on 999 patients) achieved similarly high eradication rates, but data on concomitant are still limited. The bismuth-based was associated with the higher (38.7%) incidence of side-effects. Conclusions: Data found that all triple therapies, irrespective of drug combination and therapy duration, should be abandoned in Italy due to their unacceptable low success rates. Monitoring the efficacy of standard first-line therapies in other countries could be clinically useful for both patients and clinicians.

Rescue Therapies for H. pylori Infection in Italy

Background/Aims: Curing Helicobacter pylori infection remains challenging for clinicians, as no proposed first-line therapy achieves bacterial eradication in all treated patients so that several patients need two or more consecutive treatments. Bacterial culture with antibiotics susceptibility testing is largely unachievable in Italy, and empiric second-line and rescue therapies are generally used. This study aimed to identify what eradication regimens perform better in Italy, following first-line therapy failure. Methods: We performed a literature search on PubMed for studies on standard therapy regimens used as second-line or rescue treatments performed in adult patients. Studies including modified drug combinations were not considered. Both intention-to-treat and per- protocol analyses were computed for each therapy subgroup. Results: Data from 35 studies with a total of 4830 patients were eventually considered. As a second-line therapy, Pylera® (90.6%) and a sequential regimen (89.8%) achieved eradication rates significantly higher than other therapies. For third-line therapy, a levofloxacin-based regimen and Pylera® achieved comparable eradication rates (88.2% vs. 84.7%; p = 0.2). Among therapies used as fourth (or more) attempts, Pylera® and a rifabutin-based therapy achieved 77.4% and 66.4% cure rates, respectively (p = 0.013). A therapy sequence based on the type of first-line therapy used was proposed. Conclusions: Data obtained through our review indicate that standard therapies for H. pylori eradication can be used when following an appropriate sequence, allowing clinicians to improve the cure rate without resorting to bacterial culture.

Molecular diagnosis of Helicobacter pylori infection in gastric biopsies: Evaluation of the Amplidiag® H. pylori + ClariR assay

BACKGROUND

Adapted treatments for Helicobacter pylori infection, guided by determining antimicrobial resistance, are associated with high eradication rates. We evaluated the performance of the Amplidiag^® H. pylori + ClariR PCR assay (Amplidiag^® ) for detecting H. pylori and its clarithromycin resistance from gastric biopsies taken during endoscopy in comparison to culture and our "in-house" PCR.

MATERIALS AND METHODS

A total of 127 gastric biopsies were analyzed (98 adults; 29 children). Culture, PCR Amplidiag^® , and in-house PCR were performed in parallel. The in-house PCR combined amplification and sequencing of a 267-bp fragment of the H. pylori 23S rRNA gene. Discrepancies were controlled by amplification of glmM gene.

RESULTS

For detection of H. pylori, Amplidiag^® and the in-house PCR were concordant in 118 of 127 of cases: 66 negative and 52 positive. Discrepancies were observed in nine cases, all with low bacterial load: Amplidiag^® did not detect seven biopsies positive on in-house PCR but detected two positive biopsies that were negative on in-house PCR. Among the 19 of 52 (36%) H. pylori cases resistant to clarithromycin, only four biopsies with mixed populations exhibited discordant results between the two PCR methods. The A2142T mutation was not detected by Amplidiag^® . With the in-house PCR and amplified glmM gene as the reference method, the sensitivity and specificity of Amplidiag^® was 88.5% (95% confidence interval 83-94.1) and 100%.

CONCLUSION

This study demonstrated the high sensitivity of the PCR-based Amplidiag^® H. pylori test, especially with low H. pylori load, and the probability of its clarithromycin resistance analysis. For clinical use, a well-designed trial with a large scale of samples may still be needed.

Fourteen-day high-dose esomeprazole, amoxicillin and metronidazole as third-line treatment for Helicobacter pylori infection

INTRODUCTION

The efficacy of currently recommended third-line therapies for Helicobacter pylori is suboptimal, even that of culture-guided treatments. Resistance to multiple antibiotics is the major factor related to treatment failure. The aim of this study was to evaluate the effectiveness and safety of a 14-day therapy using high-dose of amoxicillin, metronidazole and esomeprazole.

MATERIAL AND METHODS

Multicenter open-label study as a register in routine clinical practice in patients with two previous failures of eradication therapy. A triple therapy with esomeprazole 40 mg b.d., amoxicillin 1 g t.d.s and metronidazole 500 mg t.d.s for 2 weeks was administered as a third-line therapy after a first treatment including clarithromycin and a second treatment including a quinolone. Helicobacter pylori status was determined by either histology or ¹³ C-UBT both before and after treatment.

RESULTS

A total of 68 patients were included in this study. An interim analysis showed that only three out of eight patients who had received metronidazole in previous eradication regimens were cured (37%, 95% CI 8-75); as a result, after this interim analysis only metronidazole-naïve patients were included. The ITT eradication rate in metronidazole-naive patients was 64% (95% CI 51-76). Adverse events occurred in 58% of patients, all of them mild-to-moderate. Two patients (3%) did not complete >90% of the treatment because of side effects. No severe adverse events occurred.

CONCLUSION

Cure rates of this 14-day schedule using high-dose esomeprazole, amoxicillin and metronidazole as a third-line eradication regimen were suboptimal, especially in patients who had received metronidazole in previous failed eradication regimens.

Systematic review: third-line susceptibility-guided treatment for Helicobacter pylori infection

BACKGROUND

Susceptibility-guided therapies (SGTs) have been proposed as preferable to empirical rescue treatments after two treatment failures. The aim of this study was to perform a systematic review and meta-analysis evaluating the effectiveness and efficacy of SGT as third-line therapy.

METHODS

A systematic search was performed in multiple databases. Studies reporting cure rates of Helicobacter pylori with SGT in third-line therapy were selected. A qualitative analysis describing the current evidence and a pooled mean analysis summarizing the cure rates of SGT in third-line therapy was performed.

RESULTS

No randomized controlled trials or comparative studies were found. Four observational studies reported cure rates with SGT in third-line treatment, and three studies which mixed patients with second- and third-line treatment also reported cure rates with SGT. The majority of the studies included the patients when culture had been already obtained, and so the effectiveness of SGT and empirical therapy has never been compared. A pooled mean analysis including four observational studies (283 patients) showed intention-to-treat and per-protocol eradication rates with SGT of 72% (95% confidence interval 56-87%; I(2) : 92%) and 80% (95% confidence interval 71-90%; I(2) : 80%), respectively.

CONCLUSIONS

SGT may be an acceptable option as rescue treatment. However, cure rates are, at best, moderate and this approach has never been compared with a well-devised empirical therapy. The evidence in favor of SGT as rescue therapy is currently insufficient to recommend its use.

Real-Time PCR detection and quantitation of Helicobacter pylori clarithromycin-resistant strains in archival material and correlation with Sydney classification

BACKGROUND

Helicobacter pylori (H. pylori), infects gastric mucosa causing gastritis. Treatment failure is mainly due to certain genetic changes in the peptidyltransferase loop of 23S rRNA of the microorganism. The aim of the study was to evaluate genetic changes in gastric biopsies of H. pylori (+) patients that lead to clarithromycin resistance and to correlate them with histology data.

METHODS

A total of 150 H. pylori (+) gastric biopsies were studied, taken before and after eradication therapy from 75 dyspeptic patients divided in 2 groups: group A consisted of 25 H. pylori (+) triple-therapy resistant patients and group B consisted of 50 H. pylori (+) successfully treated patients. Histological classification of the H. pylori (+) gastritis was done according to the Sydney criteria. Genetic material was analyzed with the ClariRes™ RT-PCR bi-probe based assay for the determination of point mutations in the 23S rRNA gene and with a Quantitative-RT-PCR (Q-RT-PCR) method for the quantitation of H. pylori.

RESULTS

We showed that in 18/ 25 group A patients certain point mutations of 23S rRNA at sites A2142C, A2142G and A2143G had occurred. Nine of these 18 mutated cases (50%) were characterized as mixed infections. Mixed infections in 2/50 patients of group B were also observed. Using Q-RT-PCR, we found that gastric mucosal density of H. pylori correlates well with bacterial colonization. There was a statistically significant association (P<0.005) between the presence of the detected H. pylori genetic alterations and inflammation, activity and H. pylori density as histologically determined.

CONCLUSION

Certain point mutations in H. pylori genome that affect susceptibility to clarithromycin correlate with histological features of gastritis.