Helicobacter pylori strains and histologically-related lesions affect the outcome of triple eradication therapy: a study from southern Italy

A prospective study on Helicobacter pylori rapid urease test false negativity: is it time for its use in restricted situations?

BACKGROUND

Rapid urease test (RUT) is a diagnostic tool for Helicobacter pylori (H. pylori) diagnosis, based on the ability of the bacterium to produce urease. Despite it is considered simple, fast, and cheap, some conditions may cause false negativity. Therefore, the aim of this study was to compare RUT with currently recommended tests for H. pylori diagnosis.

METHODS

We enrolled consecutive patients who underwent upper endoscopy with histology, RUT, and urea breath test (UBT). Delta over baseline (DOB) >4% was considered positive for UBT. Diagnosis of infection was achieved when at least two tests were positive. The rate of false positivity of RUT was computed, and DOB value in RUT+ versus RUT- was compared by Mann-Whitney Test.

RESULTS

One hundred and sixteen consecutive patients with H. pylori infection were recruited. The male/female ratio was 35/81 and the mean age 45.2±13.1. Twenty-five patients (21.5%) were RUT-, despite being positive at both histology and UBT. On the other hand, in only two patients UBT and histology had discordant results. A full concordance of the three tests was observed in 89 patients (76.7%). DOB, additionally, was significantly higher in RUT+ patients (39.2±24.2%) than RUT- ones (26.3±18.5%; P=0.005).

CONCLUSIONS

RUT shows false negativity rate higher than 20%. Moreover, the RUT-negative patients showed a lower DOB at UBT, which is an indirect indicator of intragastric bacterial load. Therefore, it is presumable that H. pylori low amount may be a concurrent cause of false negativity. This study suggests that RUT-based H. pylori detection should be restricted to some specific conditions.

The Puzzle of Coccoid Forms of Helicobacter pylori: Beyond Basic Science

Helicobacter pylori (H. pylori) may enter a non-replicative, non-culturable, low metabolically active state, the so-called coccoid form, to survive in extreme environmental conditions. Since coccoid forms are not susceptible to antibiotics, they could represent a cause of therapy failure even in the absence of antibiotic resistance, i.e., relapse within one year. Furthermore, coccoid forms may colonize and infect the gastric mucosa in animal models and induce specific antibodies in animals and humans. Their detection is hard, since they are not culturable. Techniques, such as electron microscopy, polymerase chain reaction, loop-mediated isothermal amplification, flow cytometry and metagenomics, are promising even if current evidence is limited. Among the options for the treatment, some strategies have been suggested, such as a very high proton pump inhibitor dose, high-dose dual therapy, N-acetycysteine, linolenic acid and vonoprazan. These clinical, diagnostic and therapeutic uncertainties will represent fascinating challenges in the future.

Evolutionarily-Related Helicobacter pylori Genotypes and Gastric Intraepithelial Neoplasia in a High-Risk Area of Northern Italy

Helicobacter pylori (Hp) is the major recognized risk factor for non-cardia gastric cancer (GC), but only a fraction of infected subjects develop GC, thus GC risk might reflect other genetic/environmental cofactors and/or differences in virulence among infectious Hp strains. Focusing on a high GC risk area of Northern Italy (Cremona, Lombardy) and using archived paraffin-embedded biopsies, we investigated the associations between the Hp vacA and cagA genotype variants and gastric intraepithelial neoplasia (GIN, 33 cases) versus non-neoplastic gastroduodenal lesions (NNGDLs, 37 cases). The glmM gene and the cagA and vacA (s and m) genotypes were determined by polymerase chain reaction (PCR) and sequencing. Hp was confirmed in 37/37 (100%) NNGDLs and detected in 9/33 GINs (27%), consistently with the well-known Hp loss in GC. CagA was detected in 4/9 Hp-positive GINs and in 29/37 NNGDLs. The vacA s1a and m1 subtypes were more common in GINs than in NNGDLs (6/7 vs. 12/34, p=0.014, for s1a; 7/7 vs. 18/34, p=0.020 for m1), with significant vacA s genotype-specific variance. The GIN-associated vacA s1a sequences clustered together, suggesting that aggressive Hp strains from a unique founder contribute to GC in the high-risk area studied.

The antibiotic resistance of Helicobacter pylori to five antibiotics and influencing factors in an area of China with a high risk of gastric cancer

Background

H. pylori exhibits antibiotic resistance with regional differences. In this paper, we explored antibiotic resistance of H. pylori to five antibiotics in an area with a high risk of gastric cancer.

Results

H. pylori resistance rates to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline were 78.0, 56.0, 31.0, 9.0, and 15.0%, respectively. Double, triple, quadruple, and quintuple resistance rates were 23, 20, 6, and 4%, respectively. The clarithromycin and multidrug resistance rates were significantly higher in males than females (clarithromycin: 44.4% vs 15.2%, respectively, P = 0.002; multidrug: 75.5% vs 37.2%, respectively; P < 0.001). During the three periods of 1998–1999, 2002–2004 and 2016–2017, the resistance rates to levofloxacin and amoxicillin were increasing (OR: 2.089, 95%CI: 1.142–3.821, P = 0.017; and OR: 5.035, 95%CI: 1.327–19.105, P = 0.018, respectively). The antibiotic resistance rates were unassociated with the host disease state. Metronidazole resistance was lower in the vacAs1m1/m2 group than the vacAs1m1m2 group (65% vs 85.7%, respectively; P = 0.026). As for levofloxacin resistance, it was higher with cagA⁺ than cagA⁻ (60.9% vs 23.1%, respectively; P = 0.020) but lower with slyD⁺ than slyD⁻ (41.4% vs 68.5%, respectively; P = 0.009). Clarithromycin had a lower resistance rate with iceA⁺⁺ than iceA⁻⁺ (19.7% vs 52.4%, respectively; P = 0.017). For amoxicillin, the iceA⁺⁺ group had a lower resistance rate than the iceA⁻⁻ group (1.6% vs 27.8%, respectively; P = 0.009).

Conclusions

The total resistance rates of H. pylori to metronidazole, levofloxacin, clarithromycin, amoxicillin, and tetracycline were high in Zhuanghe. The resistanc rates to levofloxacin and amoxicillin increased over time. Clarithromycin resistance was associated with male and iceA. The resistance of metronidazole was related to vacA. Levofloxacin resistance was concerned with cagA and slyD and amoxicillin resistance was concerned with iceA. While, the antibiotic resistance of H. pylori had nothing to do with the status of gastric disease.

The interplay between mutations in cagA, 23S rRNA, gyrA and drug resistance in Helicobacter pylori

In this study, we evaluated the mutations of Helicobacter pylori associated with resistance to clarithromycin and levofloxacin. Furthermore, based on the proposed interaction between antimicrobial resistance and pathogenicity, we correlated the mutation profiles of the strains with the presence of the pathogenicity gene cagA. We analyzed 80 gastric biopsy specimens from H. pylori-infected patients for point mutations in the 23S rRNA gene region and in the gyrA gene, which are related to clarithromycin and levofloxacin resistance, respectively, and investigated the presence of the cagA gene in these strains. We observed that in the assayed biopsies, 8.7% (7/80) had mutations in the 23S rRNA gene region at positions 2143 and 2142, while 22.5% (18/80) had mutations in gyrA at codons 87 and 91. Moreover, absence of the CagA-EPIYA pathogenicity factor was observed in 68% (17/25) of resistant samples. The knowledge of the local profile of antimicrobial resistance and the complex interplay involving resistance and pathogenicity can contribute to an appropriate clinical approach.

The effect of virulence genotypes of Helicobacter pylori on eradication therapy in children

BACKGROUND/AIM

It is important to eradicate Helicobacter pylori at an early stage in patients during childhood to potentially prevent the development of H. pylori-related diseases. Studies have demonstrated that the virulence genotype of H. pylori influences the efficacy of eradication therapy. The efficacy of triple therapy has decreased significantly, which has seriously affected the clinical outcome of children with H. pylori infection. In this study we aimed to investigate the influence of virulence genotypes of H. pylori on triple eradication therapy in children.

PATIENTS AND METHODS

H. pylori strains were isolated from the gastric antrum mucosa in children with upper gastrointestinal symptoms. Polymerase chain reaction (PCR) was conducted to determine the H. pylori cagA, vacA, and iceA genotypes. All patients with H. pylori infection were administered 14-day triple therapy. After drug withdrawal for at least 4 weeks, the ¹³C-urea breath test (¹³C-UBT) was used to observe the therapeutic effect of H. pylori eradication. The eradication rates were evaluated by intention-to-treat (ITT) and per-protocol (PP) analyses.

RESULTS

A total of 107 patients were enrolled in this study. Nine patients were lost to follow-up, and 98 patients were administered eradication therapy. Based on ITT and PP analyses, the H. pylori eradication rate was 64.5% (69/107) and 70.4% (69/98), respectively. Among the successful eradication groups, the cagA-positive, vacA s1a, vacA s1c, vacA m1, vacA m2, iceA 1, and iceA 2 genes were identified in 72.8%, 68.1%, 76.9%, 60.0%, 74.6%, 71.8%, and 75.0% of strains, respectively. Of the unsuccessful eradication groups, the cagA-positive, vacA s1a, vacA s1c, vacA m1, vacA m2, iceA 1, and iceA 2 genes were identified in 27.2%, 31.9%, 23.1%, 40.0%, 25.4%, 28.2%, and 25.0% of strains, respectively. No statistically significant differences were noted in the detection rate of the H. pylori genotypes between the H. pylori successful and unsuccessful eradication groups (P > 0.05).

CONCLUSIONS

The cagA, vacA, and iceA genotypes of H. pylori are not associated with the efficacy of omeprazole-based triple therapy on the eradication of H. pylori infection in children.

The association between vacA or cagA status and eradication outcome of Helicobacter pylori infection: A meta-analysis

Background

H. pylori virulence factors, especially vacA and cagA are important in gastroduodenal disease pathogenesis and affect cure rates. This meta-analysis aimed to clarify the association between vacA or cagA status and eradication outcome of H. pylori infection.

Methods

A literature search was performed using electronic databases to identify studies. Twenty-six prospective studies were determined eligible. Meta-analytical techniques were conducted to calculate eradication rates and pooled relative ratios (RR).

Results

The eradication rate was greater approximately 10% in vacA s1 compared with vacA s2 infected patients, and the pooled RR was 1.164 (95%CI: 1.040–1.303, P = 0.008). A significant association existed between vacA s1 and higher eradication rates in Europe (RR: 1.203, 95%CI: 1.003–1.442, P = 0.046) and Asia (RR: 1.187, 95%CI: 1.028–1.371, P = 0.020), in triple therapy patients (RR: 1.175, 95%CI: 1.012–1.365, P = 0.035). Eradication rates were similar for vacA m1 and m2 genotypes (RR: 0.981, 95%CI: 0.891–1.080, P = 0.690), whereas they were higher by approximately 8% in cagA-positive compared with cagA-negative infected patients, with a pooled RR of 1.094 (95%CI: 1.025–1.168, P = 0.007). A significant association existed between cagA-positive and increased eradication rates in Europe (RR: 1.138, 95%CI: 1.000–1.295, P = 0.049) and Asia (RR: 1.118, 95%CI: 1.051–1.190, P<0.001), in using PCR (RR: 1.232, 95%CI: 1.142–1.329, P<0.001) and protein chips (RR: 1.200, 95%CI: 1.060–1.359, P = 0.004), in triple therapy patients (RR: 1.090, 95%CI: 1.006–1.181, P = 0.034).

Conclusions

Evidence indicates that infection with vacA s1, cagA-positive strains, but not vacA s2, cagA-negative, is more conducive to H. pylori eradication.

Effect of treatment failure on the CagA EPIYA motif in Helicobacter pylori strains from Colombian subjects

AIM

To evaluate effect of treatment failure on cagA and vacA genotypes in Helicobacter pylori (H. pylori) isolates from Colombia.

METHODS

One hundred and seventy-six participants infected with H. pylori from Colombia were treated during 14 d with the triple-standard therapy. Six weeks later, eradication was evaluated by ¹³C-Urea breath test. Patients with treatment failure were subjected to endoscopy control; biopsies obtained were used for histopathology and culture. DNA from H. pylori isolates was amplified using primers specific for cagA and vacA genes. The phylogenetic relationships among isolates obtained before and after treatment were established by conglomerate analysis based on random amplified polymorphic DNA (RAPD) fingerprinting.

RESULTS

Treatment effectiveness was at 74.6%. Of the participants with treatment failure, 25 accepted subjected to a second endoscopy. Prevalence of post-treatment infection was 64% (16/25) and 40% (10/25) by histology and culture, respectively. Upon comparing the cagA and vacA genotypes found before and after therapy, multiple cagA genotypes (cagA-positive and cagA-negative) were found before treatment; in contrast, cagA-negative genotypes decreased after treatment. vacA s1m1 genotype was highly prevalent in patients before and after therapy. The 3’cagA region was successfully amplified in 95.5% (21/22) of the isolates obtained before and in 81.8% (18/22) of the isolates obtained after treatment. In the isolates obtained from patients with treatment failure, it was found that 72.7% (16/22) presented alterations in the number of EPIYA motifs, compared to isolates found before treatment.

CONCLUSION

Unsuccessful treatment limits colonization by low-virulence strains resulting in partial and selective eradication in mixed infections, and acts on the cagA-positive strains inducing genetic rearrangements in cagA variable region that produces a loss or gain of EPIYA repetitions.

Is There Any Difference in the Eradication Rate of Helicobacter pylori Infection According to the Endoscopic Stage of Peptic Ulcer Disease?

BACKGROUND

The eradication rate of Helicobacter pylori (H. pylori) infection might be affected by the degree of inflammation of gastric mucosa represented by the endoscopic stage of peptic ulcer disease (PUD). The aims of this study were to evaluate the eradication rates of H. pylori infection according to the endoscopic stage of PUD and to document whether early eradication in the active stage could yield a higher eradication rate in patients with peptic ulcer bleeding (PUB).

MATERIALS AND METHODS

A total of 1,177 patients with PUD (380 gastric ulcer, 710 duodenal ulcer, and 87 combined ulcer) who received proton-pump inhibitor (PPI)-based triple therapy were included, and the eradication rates were compared by ulcer stage. Univariate and multivariate analyses were conducted to identify factors influencing eradication rate. In PUB, the eradication rates between the early eradication group (≤7 days) and the late eradication group (>7 days) were compared.

RESULTS

The eradication rates according to endoscopic stage were significantly different in gastric ulcer (active vs healing vs scarring; 84.8% vs 82.7% vs 70.6%, p = .014, respectively), but there were no significant differences in duodenal ulcer (active vs healing vs scarring; 87.6% vs 80.9%% vs 80.9% p = .169, respectively). In multivariate analyses, active ulcer as well as age younger than 50 was a significantly independent predictor of successful eradication (Odds ratio; 2.799, 95% CI; 1.659-4.723, p = .0001). The eradication rate of the early eradication group was significantly higher than the late eradication group in PUB (89.2% vs 71.9%, 95% CI; 1.265-8.269, p = .011).

CONCLUSIONS

There was a significant difference in the eradication rate according to the endoscopic stage of gastric ulcer. Active ulcer was an independent predictor of successful eradication. Furthermore, early H. pylori eradication should be considered in patients with PUB to yield a higher eradication rate.

Association of helicobacter pylori dupA with the failure of primary eradication

GOALS

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

BACKGROUND

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.

STUDY

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.

RESULTS

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).

CONCLUSIONS

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

Helicobacter pylori iceA, clinical outcomes, and correlation with cagA: a meta-analysis

Background

Although the iceA (induced by contact with epithelium) allelic types of Helicobacter pylori have been reported to be associated with peptic ulcer, the importance of iceA on clinical outcomes based on subsequent studies is controversial. The aim of this study was to estimate the magnitude of the risk for clinical outcomes associated with iceA.

Methods

A literature search was performed using the PubMed and EMBASE databases for articles published through April 2011. Published case-control studies examining the relationship between iceA and clinical outcomes (gastritis, peptic ulcer, including gastric ulcer and duodenal ulcer, and gastric cancer) were included.

Results

Fifty studies with a total of 5,357 patients were identified in the search. Infection with iceA1-positive H. pylori increased the overall risk for peptic ulcer by 1.26-fold (95% confidence interval [CI], 1.09–1.45). However, the test for heterogeneity was significant among these studies. Sensitivity analysis showed that the presence of iceA1 was significantly associated with peptic ulcer (odds ratio [OR] = 1.25, 95% CI = 1.08–1.44). The presence of iceA2 was inversely associated with peptic ulcer (OR = 0.76, 95% CI = 0.65–0.89). The presence of iceA was not associated with gastric cancer. Most studies examined the cagA status; however, only 15 studies examined the correlation and only 2 showed a positive correlation between the presence of cagA and iceA1.

Conclusion

Our meta-analysis confirmed the importance of the presence of iceA for peptic ulcer, although the significance was marginal.

Virulence factor genotypes of Helicobacter pylori affect cure rates of eradication therapy

The cure rates of Helicobacter pylori infection by using a combination of a proton pump inhibitor (PPI) and antimicrobial agents are mainly influenced by bacterial susceptibility to antimicrobial agents and the magnitude of acid inhibition during the treatment. Currently used empirical triple therapies do not reliably produce a > or =80% cure rate on an intention-to-treat basis. Therefore, tailored regimens based on relevant microbiological findings and pharmacogenomics are recommended for attaining an acceptable > or =95% cure rate. Recently, virulence factors of H. pylori, such as cagA and vacA, are reported to be major factors determining the cure rates. Individuals infected with strains with cagA-negative and vacA s2 genotypes have significantly increased risk of eradication failure of H. pylori infection. These virulence factors enhance gastric mucosal inflammation and are associated with the development of peptic ulcer and gastric cancer. H. pylori virulence factors induce proinflammatory cytokines, such as interleukin (IL)-1, IL-8, and tumor necrosis factor (TNF)- which influence mucosal inflammation and/or gastric acid secretion. When physicians select an H. pylori eradication regimen with an acceptable cure rate, they might need to consider H. pylori virulence factors, especially cagA and vacA.

Systematic review and meta-analysis: importance of CagA status for successful eradication of Helicobacter pylori infection

BACKGROUND

Some, but not all studies have provided evidence that the CagA status of Helicobacter pylori strains is a predictive factor for the outcome of eradication therapy.

AIM

To clarify the association between CagA status and eradication outcome.

METHODS

We included studies reporting the numbers of successful and failed cases in H. pylori-eradication therapy according to the CagA status. Fourteen studies (1529 patients) were included of 325 articles identified in the search. The pooled risk ratio for H. pylori-eradication failure in CagA-negative relative to CagA-positive strains and the pooled risk difference in eradication success between the two groups were used as summary statistics. Meta-regression was used for examining the source of heterogeneity.

RESULTS

The summary risk ratio for eradication failure in CagA-negative relative to CagA-positive was 2.0 (95% CI: 1.6-2.4, P < 0.001), corresponding with the summary risk difference for eradication success between the groups of 11% (95% CI: 3-19%, P = 0.011). Meta-regression analysis demonstrated that usage of polymerase chain reaction examination for CagA status and a high proportion of non-ulcer dyspepsia patients were factors for heterogeneity among studies.

CONCLUSIONS

Our meta-analysis confirmed the importance of the presence of CagA as a predictor for successful eradication of H. pylori.

Third-line rescue therapy for Helicobacter pylori infection

H pylori gastric infection is one of the most prevalent infectious diseases worldwide. The discovery that most upper gastrointestinal diseases are related to H pylori infection and therefore can be treated with antibiotics is an important medical advance. Currently, a first-line triple therapy based on proton pump inhibitor (PPI) or ranitidine bismuth citrate (RBC) plus two antibiotics (clarithromycin and amo-xicillin or nitroimidazole) is recommended by all consensus conferences and guidelines. Even with the correct use of this drug combination, infection can not be eradicated in up to 23% of patients. Therefore, several second line therapies have been recommended. A 7 d quadruple therapy based on PPI, bismuth, tetracycline and metronidazole is the more frequently accepted. However, with second-line therapy, bacterial eradication may fail in up to 40% of cases. When H pylori eradication is strictly indicated the choice of further treatment is controversial. Currently, a standard third-line therapy is lacking and various protocols have been proposed. Even after two consecutive failures, the most recent literature data have demonstrated that H pylori eradication can be achieved in almost all patients, even when antibiotic susceptibility is not tested. Different possibilities of empirical treatment exist and the available third-line strategies are herein reviewed.

Molecular biology methods for the characterization of Helicobacter pylori infections and their diagnosis

Helicobacter pylori infects approximately half of the human population; however, the outcome of infection is affected by many factors, including strain and host genotype characteristics and bacterial density within the stomach. Many molecular methods have been developed to provide information with respect to these characteristics. Methods that provide results within 24 h of endoscopy may be used to develop individualized treatment that is more effective, results in fewer side effects, cuts costs,decreases the number of treatment failures and results in the development of fewer antibiotic-resistant H. pylori strains.

Rifabutin- and furazolidone-based Helicobacter pylori eradication therapies after failure of standard first- and second-line eradication attempts in dyspepsia patients

BACKGROUND

Optimal management approach is not well defined for subjects who fail initial first- and second-line Helicobacter pylori eradication attempts and are dealt on a case-by-case basis by the specialists.

AIM

To evaluate the efficacy and safety of standard and 'rescue' eradication therapies at primary and secondary care levels.

METHODS

H. pylori infected dyspepsia patients referred to our C13 urea breath testing laboratory between January 1999 to February 2002 were included. Eradication failure at secondary care level was treated using strategies including antibiotic sensitivity testing and the use of rifabutin- and furazolidone-based therapies.

RESULTS

3280 patients received standard first-line eradication therapy, which was successful in 2530 (77%) patients. Second-line therapy (bismuth-based 'quadruple') or triple therapy (altering constituent antibiotics) was successful in 56% of 270 treated patients. Subsequent eradication attempts using rifabutin-based (n = 34) and furazolidone-based (n = 10) regimens were successful in 38% and 60% patients respectively. H. pylori eradication rates were significantly different for guidelines compliant (94.8%) and non-compliant (82%) groups (P = 0.0001). H. pylori eradication rates for non-ulcer dyspepsia (40%) and peptic ulcer disease (36%) were not significantly different.

CONCLUSIONS

Available H. pylori eradication therapies remain very effective and compliance to guidelines achieves high success rates. Furazolidone-based 'rescue' regimen achieved high eradication rates after failure of the standard first-line, second-line and rifabutin-based therapies.

The prolongation of triple therapy for Helicobacter pylori does not allow reaching therapeutic outcome of sequential scheme: a prospective, randomised study

BACKGROUND AND AIM

One-week triple therapy for Helicobacter pylori revealed, during these last few years, a decrease in the eradication rate, so that the prolongation of its duration has been proposed. A sequential scheme recently showed very satisfactory results. We performed a prospective randomised study with the aim of either evaluating whether the triple therapy prolongation may improve its effectiveness and comparing its outcome with that of sequential regimen.

PATIENTS AND METHODS

Three hundred and forty-two H. pylori positive patients completed the study. They were randomised to receive one of the following treatments: (i) a 7-day triple therapy comprising of rabeprazole (20 mg, b.i.d.) plus clarithromycin (500 mg, b.i.d.) and amoxycillin (1 g, b.i.d.); (ii) a 10-day triple therapy comprising the same scheme; (iii) a 10-day sequential regimen comprising of rabeprazole (20 mg, b.i.d.) plus amoxycillin (1 g, b.i.d.) for 5 days followed by rabeprazole (20 mg, b.i.d.) plus clarithromycin (500 mg, b.i.d.) and tinidazole (500 mg, b.i.d.) for the next 5 days. Therapeutic results were expressed using both intention-to-treat and per protocol analyses with 95% confidence intervals. A model of multivariate logistic regression analysis was performed using therapeutic outcome as a dependent variable and including endoscopic finding, smoking habit, age and sex as candidates for the model.

RESULTS

Sequential regimen showed a significant gain in the eradication rate as compared to the 7-day (P < 0.0001) and the 10-day (P < 0.01) triple therapies, respectively. Overall eradication was lower in smokers than in non-smokers, but the difference remained significant only in the 7-day triple therapy (P < 0.01). Additionally, the overall eradication was higher in peptic ulcer than dyspepsia (P < 0.01), even if this difference was significant only for both triple therapies.

CONCLUSIONS

Seven-day triple therapy achieves disappointing eradication rates in dyspeptics and smokers. Prolonging triple therapy to 10 days does not significantly improve the eradication rate. The novel 10-day sequential regimen is more effective and equally tolerated than the 10-day triple therapy.

Effectiveness and pharmaceutical cost of sequential treatment for Helicobacter pylori in patients with non-ulcer dyspepsia

BACKGROUND

A novel 10-day sequential treatment regimen recently achieved a significantly higher eradication rate than standard 7-day therapy in both peptic ulcer disease and non-ulcer dyspepsia. Its higher performance has recently been confirmed using a halved clarithromycin dose in peptic ulcer disease.

AIMS

To evaluate whether an acceptable eradication rate could also be obtained by halving the clarithromycin dose in dyspeptic patients and to assess the role of possible factors affecting the outcome of therapy.

METHODS

In a prospective, open-label study, 162 patients with non-ulcer dyspepsia and Helicobacter pylori infection, assessed by rapid urease test and histology, were enrolled. Patients were randomized to receive either 10-day sequential therapy, comprising rabeprazole 20 mg b.d. plus amoxicillin 1 g b.d. for the first 5 days, followed by rabeprazole 20 mg b.d., clarithromycin 250 mg b.d. and tinidazole 500 mg b.d. for the remaining 5 days (low-dose therapy), or a similar schedule with clarithromycin 500 mg b.d. (high-dose therapy). Four to six weeks after therapy, H. pylori eradication was assessed by endoscopy/histology.

RESULTS

A similar H. pylori eradication rate was observed following low- and high-dose regimens for both per protocol (94% vs. 95%; P = N.S.) and intention-to-treat (93% vs. 94%; P = N.S.) analyses. No major side-effects were reported. Halving the clarithromycin dose leads to a per patient saving in pharmaceutical costs of 24.6 euros. None of the variables examined affected the effectiveness of eradication of the sequential regimen.

CONCLUSION

A reduction of the clarithromycin dose does not affect H. pylori eradication with the sequential regimen in non-ulcer dyspepsia and affords lower costs.

Sequential treatment for Helicobacter pylori does not share the risk factors of triple therapy failure

BACKGROUND

Predicting factors for the outcome of conventional Helicobacter pylori triple therapy have been identified. Of these, the presence of the CagA gene is a strong predictor of successful treatment. Our preliminary data show that this factor becomes irrelevant when sequential therapy is used.

AIM

To identify predicting factors for the outcome of H. pylori eradication using two therapeutic schemes (triple and sequential) of equal duration (10 days).

METHODS

Ninety-six patients with H. pylori infection were randomly assigned to receive one of the following therapeutic schemes: group A: rabeprazole (20 mg b.d.) plus amoxicillin (1 g b.d.) for 5 days, followed by rabeprazole (20 mg b.d.) plus tinidazole (500 mg b.d.) and clarithromycin (500 mg b.d.) for a further 5 days; group B: rabeprazole (20 mg b.d.) plus amoxicillin (1 g b.d.) and clarithromycin (500 mg b.d.) for 10 days. Age, sex, smoking, endoscopic and histological findings, and CagA and VacA status were considered as candidates for a model of multivariate analysis which used therapeutic outcome as the dependent variable. CagA and VacA status were assessed by polymerase chain reaction on DNA isolated from gastric antral specimens.

RESULTS

The sequential scheme was significantly more effective than prolonged triple therapy (P < 0.05). Smoking (P < 0.001) and the absence of the CagA gene (P < 0.05) were significantly associated with the failure of triple therapy, but the effectiveness of sequential treatment was not predicted by these factors.

CONCLUSION

Our data suggest that sequential therapy is not affected by bacterial and host factors which have, until now, predicted the outcome of conventional eradication treatments.

Randomized study of different 'second-line' therapies for Helicobacter pylori infection after failure of the standard 'Maastricht triple therapy'

BACKGROUND

Triple therapy with proton pump inhibitor, clarithromycin and amoxicillin and, in the event of eradication failure, quadruple therapy with proton pump inhibitor, bismuth, tetracycline and metronidazole have been proposed in Maastricht as the optimal sequential treatment of Helicobacter pylori infection.

AIM

To compare two second-line regimens with quadruple therapy.

METHODS

One hundred and eighty patients with a previous failed course of standard therapy were randomly given one of the following 7-day treatments: ranitidine bismuth citrate 400 mg b.d. plus amoxicillin 1 g b.d. and tinidazole 500 mg b.d. (RBCAT), pantoprazole 40 mg b.d. plus amoxicillin 1 g b.d. and levofloxacin 500 mg/day (PAL) and pantoprazole 40 mg b.d., bismuth citrate 240 mg b.d., tetracycline 500 mg q.d.s. and metronidazole 500 mg b.d. (PBTM). The eradication rate was assessed by 13C-urea breath test. Side-effects and compliance were evaluated by a standardized questionnaire and by counting returned medication.

RESULTS

The RBCAT, PAL and PBTM groups achieved mean intention-to-treat eradication rates of 85%, 63% and 83%, respectively (P<0.05 for PAL vs. either RBCAT or PBTM). Compliance was optimal in all patients, although side-effects were more commonly observed in the PBTM group than in the other two patient groups (P<0.0001).

CONCLUSIONS

Both RBCAT and PBTM can be used as second-line therapies. Conversely, PAL did not achieve satisfactory eradication rates.

Treatment of Helicobacter pylori infection

Review of the recently published data on Helicobacter pylori management highlights various interesting aspects. Current H. pylori eradication guidelines generally suggest a noninvasive 'test and treat' strategy for all dyspeptic patients with certain age limits depending on the local gastric neoplasia risk. According to the 'Maastricht 2-2000 Consensus Report' treatment should be thought of as a 'package' considering first- and second-line eradication therapies together. Various centres have published their results using novel antimicrobial formulations and 'rescue' and 'sequential' therapies. Review suggests that care at the specialist level remains a challenge and guidelines are deficient particularly as regards the selection and duration of eradication therapies. Results indicate that differences for CYP2C19 genotype and the selection of proton pump inhibitors have no significant role in determining eradication rates whereas antibiotic resistance and socio-economic factors play a variable role according to different geographical areas. Compliance remains an important factor in determining clinical outcome at the primary and secondary levels worldwide.