Helicobacter pylori: from art to a science

A Randomized Controlled Trial Shows that both 14-Day Hybrid and Bismuth Quadruple Therapies Cure Most Patients with Helicobacter pylori Infection in Populations with Moderate Antibiotic Resistance

Hybrid therapy is a novel two-step treatment achieving a high eradication rate for Helicobacter pylori infection. Currently, whether this new therapy achieves a higher eradication rate than bismuth quadruple therapy remains an unanswered question. The aim of this prospective, randomized comparative study was to investigate the efficacies of 14-day hybrid therapy and bismuth quadruple therapy in the treatment of H. pylori infection. From July 2013 to June 2015, eligible H. pylori-infected subjects were randomly assigned to receive either 14-day bismuth quadruple therapy (pantoprazole, bismuth subcitrate, tetracycline, and metronidazole for 14 days) or 14-day hybrid therapy (a 7-day dual therapy with pantoprazole plus amoxicillin, followed by a 7-day quadruple therapy with pantoprazole plus amoxicillin, clarithromycin, and metronidazole). H. pylori status was examined 6 weeks after the end of treatment. Three hundred thirty H. pylori-infected participants were randomized to receive 14-day bismuth quadruple therapy (n = 164) or 14-day hybrid therapy (n = 166). The eradication rates by intention-to-treat analysis were similar: 93.9% versus 92.8%, respectively (95% confidence interval [CI], -4.3% to 5.4%; P = 0.68). Per-protocol analysis yielded similar results (96.7% versus 94.9%, respectively; P = 0.44). However, bismuth quadruple therapy had a higher frequency of adverse events than hybrid therapy (55.5% versus 15.7%, respectively; 95% CI, 30.4% to 49.2%; P < 0.001). The two treatments exhibited comparable drug adherence (93.9% versus 97%, respectively). The resistance rates of antibiotics were: clarithromycin, 16.7% of patients; amoxicillin, 1.3%; metronidazole, 25%; and tetracycline, 0%. In the bismuth quadruple therapy group, the eradication rate of metronidazole-resistant strains was lower than that of metronidazole-susceptible strains (70.0% versus 96.4%, respectively; P = 0.04). In the hybrid therapy group, no significant impact of clarithromycin or metronidazole resistance on eradication rates was identified. Both 14-day hybrid and bismuth quadruple therapies cure most patients with H. pylori infection in populations with moderate antibiotic resistance. However, the 14-day hybrid therapy has fewer adverse effects than the bismuth quadruple therapy. (This study has been registered at ClinicalTrials.gov under identifier NCT02541864.).

A Randomized Controlled Study Comparing Reverse Hybrid Therapy and Standard Triple Therapy for Helicobacter pylori Infection

Reverse hybrid therapy is an 1-step 2-phase treatment for Helicobacter pylori (H. pylori) infection with less cost than standard triple therapy. We conducted a randomized, controlled study to compare the efficacies of standard triple therapy and reverse hybrid therapy in the treatment of H. pylori infection. From October 2012 to March 2015, consecutive H. pylori-infected subjects were randomly allocated to receive either a reverse hybrid therapy (pantoprazole plus amoxicillin for 12 days and clarithromycin plus metronidazole for the initial 7 days) or a standard triple therapy (pantoprazole plus amoxicillin and clarithromycin for 12 days). H. pylori status was assessed 6 weeks after treatment. Additionally, antibiotic resistances and host CYP2C19 genotypes were examined and analyzed. A total of 440 H. pylori-infected patients were randomly assigned to receive either a reverse hybrid (n = 220) or a standard triple therapy (n = 220). The reverse hybrid group had a higher eradication rate than standard triple group either by intention-to-treat (93.6% vs. 86.8%; P = 0.016) or per-protocol analysis (95.7% vs. 88.3%; P = 0.005). The 2 patient groups exhibited similar frequencies of overall adverse events (14.1% vs. 9.5%) and drug compliance (96.8% vs. 98.6%). Clarithromycin resistance was an independent risk factor predicting eradication failure in standard triple group (P < 0.001), but not in reverse hybrid group. CYP2C19 genotypes did not affect the eradication rates in both groups. Reverse hybrid therapy can be considered for first-line treatment of H. pylori infection since the new therapy achieves a higher eradication rate than standard triple therapy with similar tolerability and less pharmaceutical cost.

The effect of Helicobacter pylori eradication therapy on the development of gastroesophageal reflux disease

BACKGROUND

It is uncertain whether the Helicobacter pylori eradication therapy makes a role in the progression of gastroesophageal reflux disease (GERD).

METHODS

A meta-analysis was undertaken to investigate the effect of H pylori eradication therapy on the development of GERD.

RESULTS

Overall, 16 cohort studies were included. The authors demonstrated that H pylori eradication had no significant effect on the occurrence of GERD in these cohort studies (odds ratio = 0.87, 95% confidence interval = 0.66-1.14, I = 32.4%, P = 0.103).

CONCLUSIONS

In general, H pylori eradication has no significant effect on the development of GERD in the long term. However, eradication therapy should be taken once there is H pylori infection, because H pylori infection is acknowledged to be a major cause of acute and chronic gastritis and peptic ulcer diseases and has been established as a definite etiologic factor for gastric cancer.

Sequential therapy achieves a higher eradication rate than standard triple therapy in Taiwan

BACKGROUND AND AIMS

Most clinical trials concerning sequential therapy have been conducted in Italy. The efficacy of sequential therapy for Helicobacter pylori (H. pylori) eradication in Asia remains unclear. The aim of this study was to compare the efficacy of sequential therapy with standard triple therapy in Taiwan.

METHODS

From January 2005 to December 2009, 233 H. pylori-infected patients receiving either a 10-day sequential therapy (40 mg pantoprazole and 1 g amoxicillin, twice daily, for the initial 5 days, followed by 40 mg pantoprazole, 500 mg clarithromycin, and 500 mg metronidazole, twice daily, for the subsequent 5 days, n = 118) or a 7-day standard triple therapy (40 mg pantoprazole, 500 mg clarithromycin, and 1 g amoxicillin twice daily for 7 days, n = 115) were included in the retrospective study. All the patients underwent a follow-up endoscopy with a rapid urease test and histological examination or a urea breath test at 8 weeks after the end of anti-H. pylori therapy to assess H. pylori status.

RESULT

Intention-to-treat analysis demonstrated a significantly higher eradication rate for the sequential group than for the triple group (93% vs 80%, respectively, P = 0.003). Per-protocol analysis also showed similar results (93% vs 80%, P = 0.005). Both groups had similar frequencies of adverse events (29% vs 22%) and drug compliance (98% vs 97%).

CONCLUSION

Sequential therapy achieves a higher eradication rate than standard triple therapy in Taiwan. The novel treatment can be used as a first-line therapy for H. pylori infection for Taiwanese.

Helicobacter pylori infection: a randomized, controlled study comparing 2 rescue therapies after failure of standard triple therapies

Antibiotic resistance to amoxicillin in second-line eradication therapy for Helicobacter pylori infection is much less frequent than resistance to metronidazole. We conducted a randomized, controlled study to compare the efficacies of standard quadruple rescue therapy and a new therapy with amoxicillin replacing metronidazole for patients failing first-line eradication treatment. We randomly assigned 120 patients who failed H. pylori eradication using a proton pump inhibitor plus clarithromycin and amoxicillin to undergo a 1-week rescue therapy with esomeprazole, bismuth subcitrate, and tetracycline plus either metronidazole (EBTM group, n = 62) or amoxicillin (EBTA group, n = 58). We used follow-up endoscopy 8 weeks after the end of treatment to assess the treatment response. We also examined and analyzed antibiotic resistances and CYP2C19 genotypes. Intention-to-treat analysis demonstrated that the EBTA group had a significantly lower eradication rate than the EBTM group (62% vs. 81%, respectively, p = 0.02). Per-protocol analysis showed similar results (64% vs. 83%, p = 0.01). However, the EBTA group had less frequency of adverse events than the EBTM group (19% vs. 44%, p < 0.01). Both groups had good drug compliance (both 97%). Antibiotic susceptibility tests showed that the frequency of amoxicillin-resistant strains was much less than that of metronidazole-resistant strains (0% vs. 54%, respectively), and there were no significant differences between H. pylori eradication rates and antibiotic resistances. In conclusion, EBTA quadruple therapy demonstrated a lower eradication rate than standard EBTM therapy in second-line rescue treatment. The discrepancy between in vitro antibiotic susceptibility and in vivo eradication response is probably due to drug interactions between combined antibiotics or some unknown causes, and should not be neglected in H. pylori therapy.

Is there an increased risk of GERD after Helicobacter pylori eradication?: a meta-analysis

OBJECTIVES

Some studies suggest that eradication of Helicobacter pylori (Hp) might increase the risk of gastroesophageal reflux disease (GERD) in a portion of patients. We aimed to conduct a meta-analysis to investigate this.

METHODS

A comprehensive, English, multiple-source literature search was performed from 1983 to February 2007. Only randomized controlled trial (RCT) and cohort studies comparing the prevalence of GERD in patients free from GERD at baseline with Hp eradication vs. those with persistent Hp were included. Quality of RCTs and cohorts was assessed by Jadad and New Castle-Ottawa scores, respectively. Meta-analysis of pooled odds ratios (ORs) was performed using Review Manager 4.2.10.

RESULTS

Twelve (7 RCTs and 5 cohorts) of 271 articles were included. In six RCTs using erosive GERD as outcome, the OR for the frequency of GERD in Hp eradicated group vs. persistent Hp group was 1.11 (0.81-1.53, P=0.52). In five RCTs using symptomatic outcome, the OR for the frequency of GERD in Hp eradicated group vs. persistent Hp was 1.22 (0.89-1.69, P=0.22). In cohort studies, the OR for the frequency of GERD in Hp eradicated group vs. persistent Hp was 1.37 (0.89-2.12; P=0.15). Test of heterogeneity was not significant for any analyses. The results were consistent in subgroup and sensitivity analyses, including cohort studies vs. RCTs, high-quality studies vs. low-quality studies, and use of endoscopic vs. symptomatic outcomes except for the subgroup of patients with peptic ulcer disease (PUD) in cohort studies (OR: 2.04 (1.08-3.85); P=0.03).

CONCLUSIONS

There is no association between Hp eradication and development of new cases of GERD in the population of dyspeptic patients. However, in cohort studies, there seems to be a twofold higher risk of development of erosive GERD in patients with PUD. The effect in RCTs of patients with PUD did not show a significant difference.

Cytotoxicity, qualitative structure–activity relationship (QSAR), and anti-tumor activity of bismuth dithiocarbamate complexes

Bismuth dithiocarbamate complexes of general formula Bi(S(2)CNR(2))(3) demonstrate potent in vitro cytotoxicity against a panel of seven human cancer cell lines; a structure-activity relationship has been established. Potency exhibited by the R=Et (2) derivative, for example, is unrivalled by standard cancer drugs with the exception of paclitaxel. In vivo studies indicate a significant anti-tumor effect exerted by (2) against both OVCAR-3, an ovarian cancer cell line, and HT-29, a colon carcinoma cell line.

Anti-CagA and anti-VacA antibodies in Helicobacter pylori-infected patients with and without peptic ulcer disease in Serbia and Montenegro

BACKGROUND

The expression of two Helicobacter pylori proteins, CagA and VacA, is associated with more severe pathogenesis and clinical outcomes of the infection. However, this association varies among geographical regions and ethnic groups. We therefore evaluated CagA and VacA seroprevalence in H. pylori-positive dyspeptic patients in Serbia and Montenegro.

METHODS

In 173 consecutive dyspeptic patients referred to endoscopy (67M, mean age 49 +/- 15, 76 smokers), immunoblot assay was used to detect serum antibodies against CagA and VacA. Presence of H. pylori infection was assessed using a rapid urease test (RUT), routine histology and serology (anti-IgG ELISA). Duodenal ulcer (DU) was diagnosed in 28, gastric ulcer (GU) in 3 and non-ulcer dyspepsia (NUD) in the remaining 142 patients.

RESULTS

129 (74.6%) patients were H. pylori-positive, 27 (96.4%) with DU, 3 (100%) with GU and 99 (69.7%) with NUD (P < 0.01); 121 (93.8%) patients carried anti-CagA antibodies and there was no difference between the DU and NUD groups. VacA antibodies were detected in sera of 50 (38.75%) and were more prevalent in patients with DU compared to the NUD group (P < 0.05).

CONCLUSIONS

In Serbia and Montenegro there is high seroprevalence of CagA-positive H. pylori strains in dyspeptic patients with and without peptic ulcer, while VacA-positive strains are more closely related to peptic ulcer disease.

Somatostatin and D cells in patients with gastritis in the course of Helicobacter pylori eradication: a six-month, follow-up study

BACKGROUND/AIMS

As well as causing chronic gastritis, Helicobacter pylori predisposes patients to peptic ulcer disease and gastric cancer, and induces gastric functional disorders. The aim of our study was to investigate the effects of H. pylori eradication therapy on the morphological and functional recovery of gastric antral and corpus D cells in patients with chronic gastritis during 6 months of follow-up.

PATIENTS AND METHODS

Forty consecutive, dyspeptic patients referred for endoscopy (31 with H. pylori infection and nine controls; mean age 49 years; 17 men, 23 women) entered the study. All patients had histological signs of gastritis but no signs of peptic ulcer or gastric cancer. Antrum (n=8) and corpus (n=6) biopsy specimens were collected for routine histology, radioimmunoassay tissue somatostatin levels, immunohistochemistry and electron microscopy, prior to and 6 months after therapy. Basal plasma somatostatin levels were determined prior to eradication, plus 6 weeks and 6 months after therapy. Eradication therapy consisted of amoxicillin, metronidazole and omeprazole.

RESULTS

Basal somatostatin plasma values in antral and corpus tissue were lower in infected patients than in the H. pylori-negative controls at the beginning of the study. A significant increase occurred after successful eradication therapy, together with an increase in the number of D cells in both regions. Changes in the D-cell ultrastructure in antral and corpus mucosa after eradication therapy suggest an increase in somatostatin synthesis and secretion.

CONCLUSIONS

The structural and functional restoration of D cells following eradication therapy indicates possible recovery of the diseased mucosa.

Antimony and bismuth compounds in oncology

The main group elements antimony and bismuth are used clinically, primarily for the treatment of Leishmaniasis (antimony) and ulcers (bismuth). Despite their medicinal efficacy, the exploration of the anti-cancer potential of antimony and bismuth compounds is not as well developed as for other metal-containing species. The results of cytotoxicity and anti-tumour screening for antimony(III), antimony(V) and bismuth(III) compounds are summarised in this review. While this is a relatively undeveloped field of research endeavour, promising anti-tumour activity has been reported, in particular for bismuth compounds.

One-week quadruple therapy is an effective salvage regimen for Helicobacter pylori infection in patients after failure of standard triple therapy

Standard triple therapy remains an important option for eradicating Helicobacter pylori (Hp) in developing countries because of its relatively low cost. However, salvage therapies after failure of this regimen remain undefined. The authors therefore investigate the efficacy of 1-week quadruple therapy as a second-line treatment of Hp infection after failure of standard triple therapy. Seventy-eight patients who failed Hp eradication using a 2-week bismuth-based triple therapy were enrolled and received a course of 1-week quadruple therapy (lansoprazole, 30 mg twice daily; bismuth subcitrate, 120 mg four times daily; clarithromycin, 500 mg twice daily; and amoxicillin, 1,000 mg twice daily) as a salvage regimen. The Hp status was reassessed 7 weeks after cessation of therapy. Among the 78 patients, Hp eradication was achieved in 65 (83%, 95% confidence interval = 75-91%) by intention-to-treat analysis. Only five (6%) patients had side effects, and all (100%) showed good drug compliance. Multivariate analysis disclosed that coffee drinking was an independent factor for treatment failure (odds ratio = 5.3, 95% confidence interval = 1.2-23.6, p = 0.028). The authors therefore conclude that their 1-week quadruple therapy is an effective salvage regimen for Hp infection after failure of standard triple therapy in the population examined. The benefits of this regimen include the high eradication rate, the short duration of treatment, fewer side effects, and good drug compliance. Coffee consumption possibly is an important factor in failure of the rescue regimen. The mechanisms underlying the association between coffee drinking and eradication failure require further research.

Eradication of Helicobacter pylori prevents ulcer development in patients with ulcer-like functional dyspepsia

BACKGROUND

Although the eradication of Helicobacter pylori infection benefits patients with gastric or duodenal ulcers, the value of eradicating the infection in the patients with functional dyspepsia (FD) remains controversial.

AIMS

To determine whether eradicating H. pylori can prevent the subsequent development of ulcers or relieve the symptoms of functional dyspepsia patients.

METHODS

In a double-blind, placebo-controlled trial, 161 patients infected with H. pylori who had functional dyspepsia were randomly assigned to 7 days of treatment with a lansoprazole-based triple therapy or placebo and then followed for 1 year. The main outcome measures were the development of peptic ulcers and the resolution of symptoms.

RESULTS

H. pylori was eradicated in 63 out of 81 patients (78%) in the treatment group and none of the 80 patients (0%) in the placebo group. During the follow-up period, two patients in the treatment group and six patients in the placebo group developed peptic ulcers at repeat endoscopy (2.5% vs. 7.5%; 95% CI: -12 to 2). The reduction in ulcer rates was statistically significant in the 'ulcer-like' sub-group (0% vs. 16.7%; 95% CI: -32 to -2), but not in the 'dysmotility-like' and 'unclassifiable' sub-groups. Regarding symptom response, the resolution rates of symptoms were similar between the treatment and placebo groups (58.0% vs. 55.0%, 95% CI: -12 to 18). Additionally, no significant differences existed in the symptom responses between the treatment and control arms in each of the dyspepsia sub-groups.

CONCLUSIONS

Eradicating H. pylori can prevent the subsequent development of peptic ulcers in the patients with 'ulcer-like' functional dyspepsia. However, this approach does not significantly reduce the symptoms of functional dyspepsia patients.

Pharmacokinetic considerations in the eradication of Helicobacter pylori

As Helicobacter pylori plays an important role in the aetiopathogenesis of peptic ulcer, therapeutic strategies aimed at maintaining long term remission have shifted from the control of intragastric pH to targeting H. pylori. According to recent international guidelines the clinical goals--rapid ulcer healing and prevention of relapse--can be best accomplished by combination therapy consisting of an antisecretory drug (proton pump inhibitor or ranitidine) and 2 antimicrobial agents (preferable amoxicillin, clarithromycin or metronidazole). When applying such multidrug regimens, possible synergy between the agents suggests that pharmacokinetic considerations might help to improve H. pylori eradication rates, which should be above 85 to 90% on an intention-to-treat basis. The present review summarises the pharmacokinetic properties and interaction potential of all drugs presently used in the various H. pylori eradication regimens, with emphasis on particular patient populations such as the elderly and those with renal impairment. The drugs considered are omeprazole, lansoprazole, pantoprazole, rabeprazole, ranitidine and ranitidine bismutrex, bismuth salts, amoxicillin, clarithromycin, azithromycin, roxithromycin, metronidazole, tinidazole and tetracycline. When addressing the clinically important questions of the efficacy, safety and costs of the recommended regimens, the impact of drug disposition on H. pylori eradication should not be neglected.