Decreased prevalence of Helicobacter pylori infection in gastroesophageal reflux disease

Epidemiology of upper gastrointestinal bleeding and Helicobacter pylori infection: review of 3,488 Thai patients

Background

The current epidemiology of upper gastrointestinal bleeding (UGIB) in Thailand is poorly understood and the reported prevalence of Helicobacter pylori infection is outdated.

Objectives

To investigate the etiologies of UGIB and prevalence of H. pylori infection in Thailand, including its association with UGIB.

Methods

We retrieved information regarding patients attending the endoscopic unit of King Chulalongkorn Memorial Hospital from June 2007 to January 2013. A database search using keywords “upper gastrointestinal bleeding” and “iron deficiency” was used. From 4,454 diagnoses, after exclusion criteria, 3,488 patients (2,042 male (58.5%) and 1,446 female (41.5%); mean age 63.3 ± 15.94 years, range 13–103 years) were included.

Results

The three most common causes of UGIB were peptic ulcer (38.2%), nonulcer-mucosal lesions (23.4%), and esophageal-related causes (20.4%). The 5 year-incidence of H. pylori was 25%–30%. The overall prevalence was 27%. The prevalence of H. pylori infection was found to decrease with age from 43.8% at <40 years to 21.7% at >79 years old. H. pylori infection was significantly associated with duodenal and gastroduodenal ulcers. Cirrhosis and nonulcer-mucosal lesions were significantly unrelated to H. pylori infection. Patients with concurrent cirrhosis with peptic ulcer were found to be negative for H. pylori infection.

Conclusion

Peptic ulcer is the leading cause of UGIB in Thailand. However, its incidence is declining. Patients who presented to hospital with UGIB were older, compared with those a decade ago. H. pylori infection plays an important role in UGIB and its incidence was stable during the past 5 years.

Association of Helicobacter pylori infection with esophageal adenocarcinoma and squamous cell carcinoma: a meta-analysis

To evaluate the relationship of Helicobacter pylori and cytotoxin-associated gene A (CagA) positive strains with esophageal neoplasm, including esophageal adenocarcinoma (EAC) and esophageal squamous cell carcinoma (ESCC), the authors conducted a meta-analysis using a predefined protocol. PubMed, Web of Science, China biology medical literature database, Wanfang, and China National Knowledge Infrastructure were searched for relevant articles from the first available year to April 8, 2013. The fixed or random effect pooled measure was selected based on heterogeneity among studies, which was evaluated using Q test and the I(2) of Higgins and Thompson. Metaregression was used to explore the sources of between-study heterogeneity. Publication bias was analyzed by Begg's funnel plot and Egger's regression test. The association was assessed by odds ratio (OR) with 95% confidence interval (CI). A total of 28 eligible studies were included in the meta-analysis. There was a significant inverse association between H. pylori infection (pooled OR, 0.57; 95% CI, 0.44-0.73) and EAC; CagA-positive H. pylori strains were less likely to be associated with EAC compared with CagA-negative strains (pooled OR, 0.64; 95% CI, 0.52-0.79). However, there was no statistically significant association between H. pylori/CagA-positive H. pylori strains infection and ESCC, and the pooled ORs were 1.16 (95% CI, 0.83-1.60) and 0.97 (95% CI, 0.79-1.19). But significant associations between CagA-positive H. pylori strains infection and ESCC risk were found in the stratified analysis of the study location (Asian and non-Asian), and the summary ORs were 0.74 (95% CI, 0.57-0.97) and 1.41 (95% CI, 1.02-1.94). H. pylori infection and CagA-positive strains are associated with decreased risk of EAC in the overall population. No significant association was found between H. pylori infection/CagA-positive strains and ESCC. But CagA-positive strains might have a positive association with ESCC in non-Asian population and an inverse association in Asian population.

Meta-analysis: eradication of Helicobacter pylori infection is associated with the development of endoscopic gastroesophageal reflux disease

OBJECTIVE

The role of Helicobacter pylori infection in the pathogenesis of gastroesophageal reflux disease (GORD) is controversial. We aimed to confirm the negative association between H. pylori infection and endoscopic GORD and further determine whether eradication of the infection is associated with the development of endoscopic GORD.

MATERIALS AND METHODS

Case-control studies comparing the prevalence of H. pylori infection between patients with and those without GORD, type A cohort studies comparing the incidence of GORD between patients with and those without anti-H. pylori eradication therapy, and type B cohort studies comparing the incidence of GORD between H. pylori-positive patients with and those without successful eradication were included. Moreover, the effects of H. pylori eradication on the development of GORD in randomized-controlled trials were also analyzed.

RESULTS

Overall, 43 studies were analyzed. Case-control studies showed a lower prevalence of H. pylori infection in patients with GORD [odds ratio 0.64, 95% confidence interval (CI) 0.49-0.83]. Type A cohort studies showed an increased incidence of GORD in patients whose H. pylori infection was successfully eradicated [risk ratio (RR) 2.50, 95% CI 1.46-4.26]. Type B cohort studies showed that patients whose H. pylori had been eradicated had a higher risk of GORD (RR 1.70, 95% CI 1.30-2.23). Moreover, randomized-controlled trials showed that H. pylori eradication leads to a higher risk of GORD (RR 1.99, 95% CI 1.23-3.22); subanalyses showed that the risk existed especially in Asian studies (RR 4.53, 95% CI 1.66-12.36).

CONCLUSION

H. pylori infection shows a negative association with the development of endoscopic GORD. Eradication of the infection may be a risk factor for de-novo endoscopic GORD, especially in Asian populations.

Berberine protects against esophageal mucosal damage in reflux esophagitis by suppressing proinflammatory cytokines

This study was performed to investigate the effects of berberine (BB) in a rat model of gastroesophageal reflux disease (GERD), induced by pylorus and forestomach ligation. We evaluated cytotoxicity and proinflammatory biomarkers (nitric oxide, interleukin (IL)-1β and prostaglandin E2) in RAW 264.7 cells in vitro and anti-inflammatory effects in vivo. A total of 54 Sprague Dawley rats were divided into six groups: intact control rats; reflux esophagitis (RE) control rats; RE rats treated with 20 mg/kg omeprazole and RE rats treated with BB at doses of 20, 40 and 60 mg/kg, respectively. All rats were fasted. RE was induced by pylorus and forestomach ligation one hour subsequent to the oral treatment. Six hours subsequent to the surgery, the rats were sacrificed, blood was collected from the abdominal vein and the esophagus and stomach were dissected. The gastric volume and the pH of the gastric juice were evaluated, prior to the esophagus being cut longitudinally and an inner mucosal area being imaged, to analyze mucosal damage indices. Proinflammatory biomarkers in the serum, including tumor necrosis factor (TNF)-α, IL-1β, IL-6 and monocyte chemoattractant protein (MCP)-1 were analyzed using an enzyme-linked immunosorbent assay (ELISA) kit, while the mRNA expression of TNF-α, IL-1β, IL-6 and plasminogen activator inhibitor (PAI)-1 was analyzed using a quantitative polymerase chain reaction (qPCR). Esophagic tissue damage in the BB groups was dose-dependently decreased compared with that in the RE control group. This result was consistent with significant reductions in the levels of proinflammatory biomarkers in the serum and in the expression of proinflammatory mRNA, specifically, TNF-α, IL-1β, IL-6 and PAI-1. The results suggest that the anti-inflammatory and protective effects of BB may attenuate the severity of RE and prevent esophageal mucosal damage, in addition to validating the use of BB as a pharmacological treatment for esophageal reflux disease.

Columnar-lined esophagus in Chinese patients with proximal gastric carcinomas

OBJECTIVE

To investigate the clinicopathological features of columnar-lined esophagus (CLE) in Chinese patients.

METHODS

Among 182 consecutive resections of proximal gastric cancer with residual esophageal tissue, 114 were eligible for the study. The maximal lengths of CLE and superficial esophageal glands (SEG) and the presence or absence of chronic inflammation (CI), lymphoid follicles (LF), Helicobacter pylori (H. pylori) infection, intestinal metaplasia (IM), pancreatic metaplasia (PM) and dysplasia were analyzed and compared with those in the adjacent proximal gastric mucosa.

RESULTS

SEG were present in 110 cases with a mean length of 5.4 mm (range 1-16 mm, 90% equal to or under 10 mm and 10% between 11-16 mm). These glands were associated with CI (95%), LF (85%), H. pylori infection (42%), IM (25%), PM (36%) and dysplasia (10%). CLE was found in 65% of the cases and was associated with SEG (mean length of 4.0 mm, range 1-13 mm, 97% within 10 mm and 3% between 11-13 mm). The frequencies of CI (97%), LF (86%), H. pylori infection (65%) and PM (46%) in CLE were similar to those in the proximal stomach (CI 90%, LF 54%, H. pylori infection 58%, PM 39%). In contrast, the frequencies of IM (37%) and dysplasia (15%) in CLE were significantly lower than those in the proximal stomach (66% and 31%, respectively; P < 0.01).

CONCLUSIONS

CLE in Chinese patients was within 10 mm in length in 97% of cases, and with SEG and H. pylori infection-related changes similar to those in the proximal stomach.

Arginine and polyamines in Helicobacter pylori-induced immune dysregulation and gastric carcinogenesis

L-arginine (L-Arg) is metabolized by nitric oxide synthase and arginase enzymes. The gastric pathogen Helicobacter pylori causes peptic ulcer disease and gastric cancer. We have shown that alterations in L-Arg availability and metabolism into polyamines contribute significantly to the dysregulation of the host immune response to this infection. Nitric oxide (NO) derived from inducible NO synthase (iNOS) can kill H. pylori. There are multiple mechanisms leading to failure of this process, including competition for L-Arg substrate by H. pylori arginase, and induction of host macrophage arginase II (Arg2) and ornithine decarboxylase (ODC). Generation of spermine by ODC inhibits iNOS translation and NO-mediated H. pylori killing. Expression of ODC is dependent on formation of a unique AP-1 complex, leading to upregulation of c-Myc as a transcriptional enhancer. Macrophage apoptosis is mediated by oxidation of spermine via the enzyme spermine oxidase (SMO) that generates hydrogen peroxide (H(2)O(2)), and thus oxidative stress-induced mitochondrial membrane polarization. Our studies have demonstrated that apoptosis occurs through a pERK → pc-Fos/c-Jun → c-Myc → ODC → SMO pathway. In gastric epithelial cells, activation of oxidative stress by H. pylori is dependent on SMO induction and results in both apoptosis and DNA damage, such that inhibition or knockdown of SMO markedly attenuates these events. In summary, L-Arg metabolism by the arginase-ODC pathway and the activation of SMO leads to H. pylori-induced DNA damage and immune dysregulation through polyamine-mediated oxidative stress and impairment of antimicrobial NO synthesis. Our studies indicate novel targets for therapeutic intervention in H. pylori-associated diseases, including gastritis, ulcer disease, and gastric cancer.

[Clinical analysis of recurrence rate and symptom improvement in gastro-esophageal reflux disease patients]

BACKGROUND/AIMS

Gastro-esophageal reflux disease (GERD) is a chronic condition, with 50-80% of patients experiencing recurrence within one year following completion of initial treatment. The present study aimed to estimate recurrence rate and treatment response in GERD patients treated with proton pump inhibitor.

METHODS

A total of 207 symptomatic GERD patients, which were confirmed by endoscopy from July 2008 till January 2009, were enrolled. They were divided into non-erosive reflux disease (NERD) group and erosive reflux disease (ERD) group by endoscopic findings. Patients were treated with lansoprazole 15 mg (NERD group) or 30 mg (ERD group) once daily for 8 weeks. The presence of symptoms was assessed in each patient at baseline and post-treatment using a questionnaire. Subsequent symptomatic recurrence on the cessation of therapy in each improved patients was checked by telephone survey or outpatient interview.

RESULTS

Ninety-four patients and 113 patients were first diagnosed with NERD and ERD, respectively. The mean post-treatment follow-up period was 24.4+/-8.5 weeks. Recurrence rate was 40.0% (NERD, 43.8%; ERD, 37.1% (p=0.224)). Recurrence time was 10.1+/-5.8 weeks (NERD 9.6 weeks; ERD, 10.6 weeks (p=0.444)). Regarding the symptom improvement after 8 week therapy with lansoprazole, 89.4% (NERD, 85.1%; ERD, 92.9% (p=0.056)) of total patients were symptomatically improved.

CONCLUSIONS

Forty percentage of GERD patients recurred within 6 months following the completion of 8 week therapy with lansoprazole. Recurrence rate, recurrence time, and rate of symptom improvement were not significantly different between NERD group treated with half dose and ERD group treated with full dose lansoprazole.

Polyamines Impair Immunity to Helicobacter pylori by Inhibiting L-Arginine Uptake Required for Nitric Oxide Production

BACKGROUND & AIMS

Helicobacter pylori-induced immune responses fail to eradicate the bacterium. Nitric oxide (NO) can kill H pylori. However, translation of inducible NO synthase (iNOS) and NO generation by H pylori-stimulated macrophages is inhibited by the polyamine spermine derived from ornithine decarboxylase (ODC), and is dependent on availability of the iNOS substrate L-arginine (L-Arg). We determined if spermine inhibits iNOS-mediated immunity by reducing L-Arg uptake into macrophages.

METHODS

Levels of the inducible cationic amino acid transporter (CAT)2, ODC, and iNOS were measured in macrophages and H pylori gastritis tissues. L-Arg uptake, iNOS expression, and NO levels were assessed in cells with small interfering RNA knockdown of CAT2 or ODC, and in gastric macrophages. The ODC inhibitor, α-difluoromethylornithine, was administered to H pylori-infected mice for 4 months after inoculation.

RESULTS

H pylori induced CAT2 and uptake of L-Arg in RAW 264.7 or primary macrophages. Addition of spermine or knockdown of CAT2 inhibited L-Arg uptake, NO production, and iNOS protein levels, whereas knockdown of ODC had the opposite effect. CAT2 and ODC were increased in mouse and human H pylori gastritis tissues and localized to macrophages. Gastric macrophages from H pylori-infected mice showed increased ODC expression, and attenuated iNOS and NO levels upon ex vivo H pylori stimulation versus cells from uninfected mice. α-Difluoromethylornithine treatment of infected mice restored L-Arg uptake, iNOS protein expression, and NO production in gastric macrophages, and significantly reduced both H pylori colonization levels and gastritis severity.

CONCLUSIONS

Up-regulation of ODC in gastric macrophages impairs host defense against H pylori by suppressing iNOS-derived NO production.

Do eosinophil numbers differentiate eosinophilic esophagitis from gastroesophageal reflux disease?

CONTEXT

Although the healthy esophageal mucosa contains no eosinophils, eosinophilic infiltration is observed in 2 major clinicopathologic settings: gastroesophageal reflux disease (GERD) and eosinophilic esophagitis (EE). The prevalence of EE is increasing in many countries, and this increase seems only partly to be due to a better awareness of the pathology, following the relatively recent description of EE. Gastroesophageal reflux disease and EE represent 2 entities that do not respond to the same treatment modalities and, thus, need to be distinguished. However, diagnostic criteria of EE have been defined arbitrarily, and the more recent articles tend to prove that the overlap with GERD is probably greater than initially believed, leading the authors to advise strict exclusion of GERD before considering the diagnosis of EE.

OBJECTIVES

To provide pathologists with the currently proposed histologic criteria of GERD and EE, to stress the need to combine these criteria with clinical data and endoscopic findings, and to outline the remaining controversies.

DATA SOURCES

This review is based on selected articles identified by a PubMed (US National Library of Medicine, Bethesda, Maryland) search of the literature in English for GERD and EE, a recent review by the American Gastroenterological Association (Bethesda), the Proceedings of the First International Gastrointestinal Eosinophil Research Symposium, and the authors' experience.

CONCLUSION

Proper identification of the etiology of eosinophilic infiltration of the esophagus allows accurate medical or surgical treatment and follow-up. Eosinophilic esophagitis and GERD diagnoses require integration of the histologic findings with the clinical and endoscopic data.

Comparing the acid-suppressive effects of three brands of generic lansoprazole with the original: pharmacokinetic bioequivalence tests do not necessarily guarantee pharmacodynamic equivalence

Generic drugs contain the same active ingredient as an original drug and have their bioequivalence proved by pharmacokinetic tests. However, few studies have been reported on whether these bioequivalence studies infer pharmacodynamic equivalence. In this study, in eight healthy Helicobacter pylori-negative CYP2C19 extensive metabolizers, we compared the acid-suppressive effects of repeated administration of 15 mg of three brands of generic lansoprazole, Taiproton, Tapizol, and Lansoral, with those of the original lansoprazole, Takepron. Median intragastric pH value for 24-h and % pH > 4 for daytime (08:00-20:00 h) and night-time were significantly higher with any lansoprazole formulation, compared with the control (P < 0.05, Wilcoxon signed-rank test). However, during the daytime, % pH > 4 with Tapizol was significantly lower than the original (P < 0.05). Compared with the original, no significantly larger, but no small range of inter-subject variations were observed in these two parameters for each of the three brands of generic lansoprazole (Bartlett test). Pharmacokinetic bioequivalence tests do not necessarily guarantee pharmacodynamic equivalence.

Prevalence of complicated gastroesophageal reflux disease and Barrett's esophagus among racial groups in a multi-center consortium

AIMS

The Clinical Outcomes Research Initiative database was used to evaluate ethnic trends in complicated reflux disease and suspected Barrett's esophagus among various racial groups.

METHODS

Endoscopic findings for procedures performed January 2000-December 2005 for any indication and for reflux-related indications were reviewed by racial group.

RESULTS

Of 280,075 procedures examined, Hispanics were the most likely to have esophagitis (Hispanic 19.6%, white 17.3%, black 15.8%, Asian/Pacific Islander 9.5%, P-value<0.0001), and white subjects were most likely to have suspected BE (white 5.0%, Hispanic 2.9%, Asian/Pacific Islander 1.8%, black 1.5%, P-value<0.0001). Endoscopies performed for reflux-related indications had similar trends for esophagitis and esophageal stricture. Among reflux/Barrett's screening procedures adjusted for age and gender, Hispanics were most likely to have esophagitis (OR=1.28, P-value<0.0001) compared to Caucasians.

CONCLUSION

Our results demonstrate an association of suspected Barrett's esophagus and stricture with white patients and esophagitis with Hispanic patients. These findings need to be followed-up with further study.

L-arginine availability regulates inducible nitric oxide synthase-dependent host defense against Helicobacter pylori

Helicobacter pylori infection of the stomach causes an active immune response that includes stimulation of inducible nitric oxide (NO) synthase (iNOS) expression. Although NO can kill H. pylori, the bacterium persists indefinitely, suggesting that NO production is inadequate. We determined if the NO derived from iNOS in macrophages was dependent on the availability of its substrate, L-arginine (L-Arg). Production of NO by H. pylori-stimulated RAW 264.7 cells was dependent on the L-Arg concentration in the culture medium, and the 50% effective dose for L-Arg was 220 microM, which is above reported plasma L-Arg levels. While iNOS mRNA induction was L-Arg independent, iNOS protein increased in an L-Arg-dependent manner that did not involve changes in iNOS protein degradation. L-lysine, an inhibitor of L-Arg uptake, attenuated H. pylori-stimulated iNOS protein expression, translation, NO levels, and killing of H. pylori. While L-Arg starvation suppressed global protein translation, at concentrations of L-Arg at which iNOS protein was only minimally expressed in response to H. pylori, global translation was fully restored and eukaryotic translation initiation factor alpha was dephosphorylated. H. pylori lacking the gene rocF, which codes for a bacterial arginase, induced higher levels of NO production by increasing iNOS protein levels. When murine gastric macrophages were activated with H. pylori, supraphysiologic levels of L-Arg were required to permit iNOS protein expression and NO production. These findings indicate that L-Arg is rate limiting for iNOS translation and suggest that the levels of L-Arg that occur in vivo do not permit sufficient NO generation by the host to kill H. pylori.

Helicobacter pylori, ethnicity, and the gastroesophageal reflux disease spectrum: a study from the East

BACKGROUND

Ethnic differences in gastroesophageal reflux disease (GERD) and its complications as well as racial variations in the prevalence of Helicobacter pylori infection are well documented. Nevertheless, the association between reflux disease, H. pylori, and race has not been adequately explored.

AIMS

We estimated the strength of the association between H. pylori, ethnicity, and the gastroesophageal reflux disease (GERD) spectrum, including Barrett's esophagus, in Asian patients presenting for endoscopy in a tertiary referral center.

METHODS

Prospectively, we studied 188 consecutive patients with GERD, short- and long-segment Barrett's esophagus, and controls. All patients underwent gastroscopy with gastric biopsies to assess H. pylori, gastritis, and atrophy. CagA status and H. pylori infection were determined by immunoblot assay.

RESULTS

The overall prevalence of H. pylori infection was 52.1% (of which 77.6% were cagA(+)) and was lowest in the long-segment Barrett's esophagus group (36.7%) (p = .048). When Barrett's esophagus was present, the length of abnormality was 44.8% shorter in the presence of H. pylori (p = .015). Indians had the highest prevalence of H. pylori (75%) and Malays the lowest (19.6%) (p < .001). In Indians, increased prevalence of H. pylori and cagA-positive strains was associated with reduced severity of GERD (p < .004 and p < .001, respectively), a trend not apparent in the other races. Corpus atrophy, which was almost exclusively associated with H. pylori, was highest in Indians as compared to the other races (p = .013).

CONCLUSIONS

Presence of H. pylori was associated with a reduced severity of GERD spectrum disease in Asians, especially Indians. H. pylori infection may protect against complicated reflux disease via induction of corpus atrophy.

Which has superior acid-suppressive effect, 10 mg omeprazole once daily or 20 mg famotidine twice daily? Effects of single or repeated administration in Japanese Helicobacter pylori-negative CYP2C19 extensive metabolizers

Low-dose omeprazole is superior to full-dose famotidine in maintenance therapy for gastroesophageal reflux disease, whereas "on-demand" famotidine is more effective for relief of episodes of heartburn. To explain this apparent discrepancy, intragastric pH was measured for 24-hr seven times in eight Japanese Helicobacter pylori-negative cytochrome P450 2C19 extensive metabolizers; on Days 1, 8, and 15 of repeated administration of 10 mg of omeprazole once daily and of 20 mg of famotidine twice daily and before medication. During repeated administration of omeprazole, mean intragastric pH and % time that intragastric pH > 4.0 were significantly higher and became greater. With famotidine, although these parameters were significantly higher, the degrees became smaller. Consequently, acid-suppressive effect was in the order; omeprazole < famotidine on Day 1, omeprazole approximately famotidine on Day 8, and omeprazole >famotidine on Day 15. This discrepancy possibly results from the "potentiation" of acid-suppressive effect of omeprazole and the "tolerance" phenomenon in respect to famotidine.

Laryngopharyngeal reflux finding scores correlate with gastroesophageal reflux disease and Helicobacter pylori expression

CONCLUSION

The expression of Helicobacter pylori (HP) positivity and degree of gastroesophageal reflux disease (GERD) correlate with laryngopharyngeal reflux (LPR). HP positivity and degree of GERD were more adverse in patients with a reflux finding score (RFS) of 7 or more.

OBJECTIVE

We aimed to investigate the relationship between RFS and inflammation of the lower part of the esophagus as well as RFS and HP infection.

PATIENTS AND METHODS

Forty-five consecutive patients were analyzed prospectively. The degree of LPR was evaluated using the RFS method. The degree of GERD, lower esophageal mucosal inflammation, and antral HP positivity were evaluated using endoscopic surveys.

RESULTS

The mean RFS of the whole population was 11.5+/-4.4. The mean RFS of patients who had lower esophageal mucosal inflammation was 7+/-0.1, 8.1+/-1.3, 13.9+/-3.7, and 16.6+/-3.5, for grades A, B, C and D, respectively. The RFS of patients according to HP expression was as follows: 7.2+/-0.4, 9.3+/-3.07, 12.7+/-3.16, and 17.8+/-2.1, for normal (score 0), score I, score II, and score III, respectively.

Lower prevalence of Helicobacter pylori infection with vacAs1a, cagA-positive, and babA2-positive genotype in erosive reflux esophagitis disease

BACKGROUND

Increased prevalence of esophagitis has been recognized in the West. Helicobacter pylori infection, particularly virulent strains, is proposed as a protective factor against the development of gastroesophageal reflux disease. To evaluate the relationship of reflux esophagitis with virulent H. pylori infection, we studied the prevalence of reflux esophagitis among H. pylori-infected and -uninfected patients and the genotype of isolates in Taiwan.

METHODS

Patients who had routine physical examination were investigated. The severity of esophagitis was evaluated using the Los Angeles grading system. H. pylori status was assessed by histology, rapid urease test, and bacterial culture. Genotyping of vacA, cagA, and babA2 was determined by polymerase chain reaction (PCR). Risk factors for severe esophagitis were evaluated.

RESULTS

Reflux esophagitis was found in 21.2% of 1622 patients. The prevalence of H. pylori infection was found in 33.0% of 276 patients with reflux esophagitis compared with 67.5% of 378 patients with normal esophagus (p < .001). Esophagitis occurred in a significantly lower rate among H. pylori-positive patients with peptic ulcer than those without peptic ulcer. cagA, babA2, and vacAs1a were detected in 100% of 143 isolates. Factors that predicted severe esophagitis included age, gender, and hiatus hernia but not H. pylori infection.

CONCLUSIONS

Our study suggests significantly lower incidence of H. pylori infection with the triple-positive virulent genotype in patients with reflux esophagitis in Taiwan.

Helicobacter pylori-induced macrophage apoptosis requires activation of ornithine decarboxylase by c-Myc

Helicobacter pylori infection causes chronic inflammation of the gastric mucosa that results from an ineffective immune response. We have demonstrated that one underlying mechanism is induction of macrophage apoptosis mediated by polyamines. The transcription factor c-Myc has been linked to induction of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine synthesis. We determined whether H. pylori stimulates transcriptional activation of ODC in macrophages, whether this occurs via c-Myc, and whether these events regulate activation of apoptosis. H. pylori induced a significant increase in ODC promoter activity that peaked at 6 h after stimulation and was closely paralleled by similar increases in ODC mRNA, protein, and enzyme activity. By 2 h after stimulation, c-Myc mRNA and protein expression was induced, protein was translocated to the nucleus, and there was specific binding of a consensus probe for c-Myc to nuclear extracts. Both an antennapedia-linked inhibitor of c-Myc binding (Int-H1-S6A,F8A) and transfection of a c-Myc dominant-negative construct significantly attenuated H. pylori-induced ODC promoter activity, mRNA, enzyme activity, and apoptosis in parallel. Transfection of ODC small interfering RNA inhibited ODC activity and apoptosis to the same degree as inhibition of c-Myc binding. These studies indicate that c-Myc is an important mediator of macrophage activation and may contribute to the mucosal inflammatory response to pathogens such as H. pylori by its effect on ODC.

Helicobacter pylori infection: a protective factor for esophageal squamous cell carcinoma in a Taiwanese population

AIM

Many researchers have reported the inverse relationship between Helicobacter pylori (H. pylori) infection and esophageal adenocarcinoma risk, but very few studies have examined the association between H. pylori infection and the development of esophageal squamous-cell carcinoma (ESCC). Therefore, the aim of this study is to evaluate the relationship between H. pylori infection and ESCC risk.

METHOD

Subjects were cancer cases, pathologically proven to have ESCC, in two large medical centers in Kaohsiung metropolitan of southern Taiwan between August 2000 and May 2003. Controls were from the healthy subjects who lived in Kaohsiung metropolitan and voluntarily participated in one large multiyear of gene-environmental study. In total, 127 cases (116 males and 11 females) and 171 controls (161 males and 10 females) were recruited in the same period of time for interviews. H. pylori seropositivity was determined by an enzyme-linked immunosorbant assay measuring IgG.

RESULTS

A total of 28 (22.1%) and 74 (43.3%) out of 127 cases and 171 controls, respectively, had positive H. pylori infection. After adjusting for other covariates, subjects with positive H. pylori infections had a significantly reduced risk (adjusted odds ratio (AOR) = 0.51; 95% CI = 0.27-0.96; p= 0.037) of developing ESCC than those without. This result was even more pronounced in the groups of younger subjects, nonsmokers, or nondrinkers. In addition, among the 117 cancer patients who provided information about site of cancer lesion, the present study found that subjects with cancer lesions in the lower third of the esophagus had significantly fewer positive H. pylori infections (AOR = 0.34; 95% CI = 0.14-0.80; p= 0.013) than controls.

CONCLUSION

Our findings suggest that H. pylori infection may protect against the development of ESCC. Additional studies are needed to confirm these findings.

Review article: influence of Helicobacter pylori on gastro-oesophageal reflux disease in Japan

There is circumstantial evidence that infection with Helicobacter pylori is relatively protective for the occurrence of gastro-oesophageal reflux disease (GERD). It has been suggested that the Japanese population are protected against reflux oesophagitis by their high prevalence of H. pylori associated gastritis. Such gastritis, when becoming chronic, can lead to gastric atrophy, thereby reducing the likelihood of GERD. If this hypothesis is correct, the effects of H. pylori induced gastritis may be an important factor determining the earlier lower prevalence of oesophagitis in Japan, where this infection is especially common. In support of this idea a reduced prevalence of H. pylori infection in Japan, as is now being observed in young Japanese adults, may be, at least in part, responsible for the upsurge in the number of cases of reflux disease in Japan. Concomitantly, H. pylori eradication therapy in patients with gastritis or peptic ulcer disease, which is associated with an increase in gastric acid secretion, may also be at least partly responsible for the increased prevalence of reflux oesophagitis in the Japanese population.

Spermine causes loss of innate immune response to Helicobacter pylori by inhibition of inducible nitric-oxide synthase translation

Helicobacter pylori infection of the stomach elicits a vigorous but ineffective host immune and inflammatory response, resulting in persistence of the bacterium for the life of the host. We have reported that in macrophages, H. pylori up-regulates inducible NO synthase (iNOS) and antimicrobial NO production, but in parallel there is induction of arginase II, generating ornithine, and of ornithine decarboxylase (ODC), generating polyamines. Spermine, in particular, has been shown to restrain immune response in activated macrophages by inhibiting proinflammatory gene expression. We hypothesized that spermine could prevent the antimicrobial effects of NO by inhibiting iNOS in macrophages activated by H. pylori. Spermine did not affect the up-regulation of iNOS mRNA levels but in a concentration-dependent manner significantly attenuated iNOS protein levels and NO production. Reduction in iNOS protein was due to inhibition of iNOS translation and not due to iNOS degradation. ODC knockdown with small interfering (si) RNA resulted in increased H. pylori-stimulated iNOS protein expression and NO production without altering iNOS mRNA levels. When macrophages were cocultured with H. pylori, killing of bacteria was enhanced by transfection of ODC siRNA and prevented by addition of spermine. These results identify a mechanism of immune dysregulation induced by H. pylori in which stimulated spermine synthesis by the arginase-ODC pathway inhibits iNOS translation and NO production, leading to persistence of the bacterium and risk for peptic ulcer disease and gastric cancer.

The effect of Helicobacter pylori eradication on gastroesophageal reflux disease

BACKGROUND

The effect of Helicobacter pylori (H. pylori) eradication on gastroesophageal reflux disease is controversial. We aimed to investigate the effect of H. pylori eradication in this group of patients.

MATERIALS AND METHODS

Thirty-four consecutive patients with H. pylori infection and reflux esophagitis (grade 1 or 2) were enrolled into the study. Twenty-four hour intra-esophageal pH recording and esophageal manometry were performed before and 3 months after eradication of H. pylori, which was achieved using lansoprazole 30 mg b.i.d., amoxycillin 1 g b.i.d., and clarithromycin 500 mg b.i.d. for 14 days. H. pylori was evaluated in biopsy specimens taken from the antrum and corpus by rapid urease test and by histopathologic examination before and 3 months after eradication.

RESULTS

Eighteen patients (11 men and 7 women, median age 42 years) completed the study. Three months after the treatment, there was no significant change in any of the 24-hour esophageal pH recording parameters and mean lower esophageal sphincter resting pressure (P > 0.05). The percentage of total time esophageal pH <4 increased in 10 patients, and decreased in 8 patients. There was a significant decrease in the scores of heartburn and regurgitation (P < 0.01). Esophagitis persisted in 16 patients and disappeared in 2 patients. Esophagitis score decreased in 6 patients, and did not change in 12 patients (P < 0.05).

CONCLUSION

H. pylori eradication does not have any effect on gastroesophageal acid reflux in patients with reflux esophagitis 3 months after eradication, but significant improvement is achieved in some reflux associated symptoms.

H. pylori and GERD: is less more?

Does chronic Helicobacter pylori gastritis prevent gastroesophageal reflux disease (GERD) and its sequelae? Yes, no, life should be so simple. A quick Medline search on the paired terms identified 527 citations since 1988 and that tells you something right there. Evidently, this is a complex relationship and attempting to reduce it to a yes/no answer is just not going to work. Perusing the literature, it becomes apparent that some combination of three component questions are in fact being asked: (i) Is it biologically plausible that H. pylori gastritis will reduce the occurrence of GERD? (ii) Is there an inverse epidemiological relationship between H. pylori infection and GERD? and (iii) Will the eradication of H. pylori unleash an epidemic of GERD? Each of these questions entails a unique set of consideration. We will consider each in turn.

The role of cagA Helicobacter pylori strains in gastro-oesophageal reflux disease

BACKGROUND AND AIMS

The role of Helicobacter pylori infection in gastro-oesophageal reflux disease is controversial. The aim of this study was to evaluate the prevalence of colonization by cagA-positive and cagA-negative H. pylori strains in the spectrum of gastro-oesophageal reflux disease.

METHODS

A total of 108 patients (50 male/58 female; mean age, 50.3 years) with dyspepsia and peptic ulcer or erosive gastritis/duodenitis were categorized into patients without reflux and patients with reflux oesophagitis graded from I to IV. All patients underwent upper endoscopy with biopsies of the antrum. H. pylori was detected by histology, urease test and polymerase chain reaction. The cagA status was diagnosed in the gastric biopsy by polymerase chain reaction.

RESULTS

The overall prevalence of H. pylori colonization in patients with reflux was 68.6% and was 70.2% in those without oesophageal disease (P = 0.862). Colonization by cagA-positive strains was also not statistically different between the two groups (31.4% versus 40.4%, P = 0.332). However, patients with grades II-IV reflux oesophagitis were less colonized by the bacterium (36.4%) than patients with grade I oesophagitis (77.5%) (P = 0.009). H. pylori cagA-positive strains were also less likely to colonize the stomach of patients with grades II-IV oesophagitis (0%), than grade I reflux oesophagitis (40%) patients and controls (40.4%).

CONCLUSIONS

Infection of the stomach by H. pylori and especially by H. pylori cagA strains may play a protective role against the development of the most severe forms of gastro-oesophageal reflux disease.

Randomised controlled trial of effects of Helicobacter pylori infection and its eradication on heartburn and gastro-oesophageal reflux: Bristol helicobacter project

OBJECTIVES

To investigate the effects of Helicobacter pylori infection and its eradication on heartburn and gastro-oesophageal reflux.

DESIGN

Cross sectional study, followed by a randomised placebo controlled trial.

SETTING

Seven general practices in Bristol, England.

PARTICIPANTS

10,537 people, aged 20-59 years, with and without H pylori infection (determined by the (13)C-urea breath test).

MAIN OUTCOME MEASURES

Prevalence of heartburn and gastro-oesophageal acid reflux at baseline and two years after treatment to eradicate H pylori infection.

RESULTS

At baseline, H pylori infection was associated with increased prevalence of heartburn (odds ratio 1.14, 95% confidence interval 1.05 to 1.23) but not reflux (1.05, 0.97 to 1.14). In participants with H pylori infection, active treatment had no effect on the overall prevalence of heartburn (0.99, 0.88 to 1.12) or reflux (1.04, 0.91 to 1.19) and did not improve pre-existing symptoms of heartburn or reflux.

CONCLUSIONS

H pylori infection is associated with a slightly increased prevalence of heartburn but not reflux. Treatment to eradicate H pylori has no net benefit in patients with heartburn or gastro-oesophageal reflux.

Helicobacter pylori and Gastroesophageal Reflux Disease

Since the rediscovery of Helicobacter pylori two decades ago, it has become increasingly clear that the true relationships between this organism and diseases of the upper gastrointestinal tract are highly complex. H. pylori colonization is a strong risk factor for peptic ulceration and distal gastric cancer; however, gastritis has no adverse consequences for most hosts, and the prevalence of H. pylori is inversely related to gastroesophageal reflux disease (GERD) and its sequelae, which include Barrett's esophagus and esophageal adenocarcinoma. One clinical implication stemming from these data is that H. pylori eradication may not be appropriate in certain human populations due to potential beneficial effects conferred by persistent gastric inflammation. However, the majority of published intervention trials indicate that H. pylori treatment neither leads to the development of clinically significant de novo esophagitis nor exacerbates existing reflux disease. Superimposed upon these observations are reports that long-term acid suppression induced by proton-pump inhibitors (PPIs) in conjunction with H. pylori colonization may enhance the development of atrophic gastritis, a well-recognized histologic step in the progression to intestinal-type gastric cancer. Therefore, current evidence-based recommendations regarding management of H. pylori-positive individuals with GERD include the following. H. pylori should not be treated with the intent to either improve reflux symptoms or prevent the development of reflux complications. However, if patients are to receive long-term acid suppressive therapy, they should be tested for H. pylori and treated if positive, due to the potential for PPIs to accelerate atrophy within H. pylori-infected mucosa. Optimal first-line regimens in this country consist of a PPI in combination with clarithromycin and either amoxicillin or metronidazole (triple therapy) for at least 7, but preferably 10, days. Because the most effective second-line regimens contain metronidazole, it is advisable to use amoxicillin instead of metronidazole as first-line therapy in order to optimize results should subsequent therapy be required. If first-line regimens fail to eliminate H. pylori, patients should receive quadruple therapy consisting of a PPI, bismuth subsalicylate, metronidazole, and tetracycline for 14 days. Due to the availability and accuracy of noninvasive diagnostic tests for H. pylori, it is recommended that successful cure be confirmed after intervention.

Prevalence of Helicobacter pylori in patients with gastro-oesophageal reflux disease: systematic review

OBJECTIVES

To ascertain the prevalence of Helicobacter pylori in patients with gastro-oesophageal reflux disease and its association with the disease.

DESIGN

Systematic review of studies reporting the prevalence of H pylori in patients with and without gastro-oesophageal reflux disease.

DATA SOURCES

Four electronic databases, searched to November 2001, experts, pharmaceutical companies, and journals.

MAIN OUTCOME MEASURE

Odds ratio for prevalence of H pylori in patients with gastro-oesophageal reflux disease.

RESULTS

20 studies were included. The pooled estimate of the odds ratio for prevalence of H pylori was 0.60 (95% confidence interval 0.47 to 0.78), indicating a lower prevalence in patients with gastro-oesophageal reflux disease. Substantial heterogeneity was observed between studies. Location seemed to be an important factor, with a much lower prevalence of H pylori in patients with gastro-oesophageal reflux disease in studies from the Far East, despite a higher overall prevalence of infection than western Europe and North America. Year of study was not a source of heterogeneity.

CONCLUSION

The prevalence of H pylori infection was significantly lower in patients with than without gastro-oesophageal reflux, with geographical location being a strong contributor to the heterogeneity between studies. Patients from the Far East with reflux disease had a lower prevalence of H pylori infection than patients from western Europe and North America, despite a higher prevalence in the general population.

Acid exposure and altered acid clearance in GERD patients treated for Helicobacter pylori infection

BACKGROUND

After the eradication of Helicobacter pylori, an increased incidence of gastroesophageal reflux disease and acid gastric secretion have been reported.

AIM

To evaluate the effect of Helicobacter pylori-eradication on proximal and distal gastroesophageal reflux and acid clearance in patients with gastroesophageal reflux disease.

PATIENTS AND METHODS

Sixty-eight gastroesophageal reflux disease patients (age range 18-61 years) were studied by upper endoscopy. All underwent esophageal manometry and dual probe 24-h pH-metry.

RESULTS

Percent of time at pH<4 was significantly increased in the proximal esophagus of Helicobacter pylori-eradicated patients compared to Helicobacter pylori-negative (2.4+/-0.5 vs. 1.0+/-0.2; p<0.01); no differences were found in the distal esophagus (14.0+/-3.7 vs. 9.0+/-1.4%, NS). The total number of reflux episodes was significantly higher in the proximal oesophagus of Helicobacter pylori-eradicated patients (37+/-3 vs. 22+/-3, p<0.05). In the distal esophagus, acid clearance was significantly longer, both during total time (1.4+/-0.2 vs. 0.8+/-0.7 min, p<0.01), and in the supine period (8.5+/-2.7 vs. 2.7+/-0.4 min, p<0.05). No differences were reported in the manometric parameters of the two groups of patients.

CONCLUSION

In patients with gastroesophageal reflux disease, Helicobacter pylori eradication is associated with increased acid exposure of the proximal esophagus and delayed distal acid clearance.

Review article: Helicobacter pylori and reflux disease

The falling prevalence of Helicobacter pylori infection and related diseases (peptic ulcer disease, gastric cancer) in developed countries has been paralleled by an increased recognition of gastro-oesophageal reflux and its complications. These epidemiological data do not support a role for H. pylori in the pathogenesis of reflux disease, but suggest a negative association with the increasing incidence of oesophageal diseases. This has led some investigators to propose a 'protective' role of H. pylori infection against the development of oesophageal diseases. In these patients, pre-existing lower oesophageal sphincter dysfunction, susceptibility to reflux, unmasking of latent reflux and the patterns and severity of gastritis are probably important factors contributing to the development of oesophageal diseases. The most likely mechanism by which H. pylori infection may protect against reflux is by decreasing the potency of the gastric refluxate in patients with corpus-predominant gastritis. The prevalence of H. pylori infection in patients with reflux disease is probably no greater than that in those without reflux, and there are conflicting data indicating that reflux symptoms or erosive oesophagitis develop after H. pylori eradication. It is also unclear whether H. pylori augments the antisecretory effects of proton pump inhibitors or accelerates the development of atrophic gastritis.

Improvement of reflux symptoms 3 years after cure of Helicobacter pylori infection: a case-controlled study in the Japanese population

BACKGROUND

Development of reflux esophagitis is one of the adverse effects that cause concern in relation to curative treatment of Helicobacter pylori infection. However, recent studies present a rather negative association between curative treatment and development of reflux esophagitis or reflux symptoms. Therefore, this issue has remained controversial. Accordingly, we investigated the long-term adverse effects of H. pylori eradication treatment in special reference to development of reflux symptoms.

PATIENTS AND METHODS

We conducted a case controlled study by mailing structured questionnaires on past (before curative treatment or 3 years previously) and current status. A case was an endoscopically confirmed peptic ulcer patient with confirmed cure of the infection after eradication treatment 3 years previously and a control was one who had not undergone the eradication treatment during the same period. We studied 241 pairs who matched for age, gender, and type of ulcer disease (GU, DU or GDU). Of these pairs, 81.3% were male and the mean age was 52.6 +/- 9.6 year (range 23-76).

RESULTS

The rates of patients with improved reflux symptoms in the case and control groups were 65.4% and 30.4%, respectively, with the rate being significantly greater in the case group. On the contrary, the rates of those with worsened reflux symptoms were similar (5.1% and 7.6%). Regarding general events, the rate of patients with decreased frequency of hospital visits and of those who regularly used antiacid medications were significantly decreased in the case group. Furthermore, the case group experienced significantly fewer hospital admissions for various diseases in this 3-year period. However, a significantly greater number of case group patients than control subjects gained weight.

CONCLUSION

Reflux symptoms as well as general well-being were significantly improved after cure of H. pylori infection.

Symposium: Helicobacter pylori and clinical risks--focus on gastro-oesophageal reflux disease

Helicobacter pylori is a gastric pathogen that is a major cause of peptic ulcer disease, has a role in mucosa-associated lymphoid tissue (MALT) lymphoma and is associated with gastric cancer. Yet, in a large proportion of the human population, H. pylori infection has no apparent adverse clinical consequences. Furthermore, recent research suggests that H. pylori may even confer protection against gastroesophageal reflux disease. The conflicting evidence surrounding H. pylori infection was discussed at a sponsored symposium in Helsinki, introduced by Professor P. Malfertheiner, with papers presented by Dr H. J. O'Connor, Professor R. M. Genta, Dr P. Unge and Professor A. T. R. Axon. Emerging epidemiological and retrospective evidence suggests that the presence of H. pylori infection may provide some protection against gastroesophageal reflux disease, but there is other evidence that shows no benefit of H. pylori for the protection of the oesophagus. It was felt that prospective, multicentre studies are needed to explore the H. pylori-gastroesophageal disease relationship further, to avoid confusing potential benefits with known risks. Following the symposium, a discussion on the relative risks and benefits for H. pylori eradication was provided by Professor Axon and Professor Blaser. Eradication of H. pylori has been recommended in a series of management guidelines issued by consensus groups. However, accurate estimates of the relative risks and benefits of H. pylori infection in the general population, as well as in specific patient groups, is essential in order to develop a management strategy.

Helicobacter pylori induces macrophage apoptosis by activation of arginase II

Helicobacter pylori infection induces innate immune responses in macrophages, contributing to mucosal inflammation and damage. Macrophage apoptosis is important in the pathogenesis of mucosal infections but has not been studied with H. pylori. NO derived from inducible NO synthase (iNOS) can activate macrophage apoptosis. Arginase competes with iNOS by converting L-arginine to L-ornithine. Since we reported that H. pylori induces iNOS in macrophages, we now determined whether this bacterium induces arginase and the effect of this activation on apoptosis. NF-kappa B-dependent induction of arginase II, but not arginase I, was observed in RAW 264.7 macrophages cocultured with H. pylori. The time course of apoptosis matched those of both arginase and iNOS activities. Surprisingly, apoptosis was blocked by the arginase inhibitors N(omega)-hydroxy-L-arginine or N(omega)-hydroxy-nor-L-arginine, but not by the iNOS inhibitor N-iminoethyl-L-lysine. These findings were confirmed in peritoneal macrophages from iNOS-deficient mice and were not dependent on bacterial-macrophage contact. Ornithine decarboxylase (ODC), which metabolizes L-ornithine to polyamines, was also induced in H. pylori-stimulated macrophages. Apoptosis was abolished by inhibition of ODC and was restored by the polyamines spermidine and spermine. We also demonstrate that arginase II expression is up-regulated in both murine and human H. pylori gastritis tissues, indicating the likely in vivo relevance of our findings. Therefore, we describe arginase- and ODC-dependent macrophage apoptosis, which implicates polyamines in the pathophysiology of H. pylori infection.

Effect of Helicobacter pylori eradication on oesophageal acid exposure in patients with reflux oesophagitis

BACKGROUND

The effect of Helicobacter pylori eradication on reflux oesophagitis is unclear.

AIM

To study the effect of H. pylori eradication on oesophageal acid exposure and disease severity in patients with reflux oesophagitis.

METHODS

Patients with reflux oesophagitis and H. pylori infection were recruited for 24-h oesophageal pH-metry. They were then randomly assigned to receive either treatment for H. pylori eradication (1-week omeprazole-based triple therapy, followed by 7-week omeprazole) or omeprazole alone (8-week omeprazole). Uninfected patients were recruited as controls. Endoscopy, pH monitoring and symptom assessment were repeated at 26 weeks.

RESULTS

Forty patients (25 H. pylori-positive and 15 uninfected) with erosive oesophagitis were studied. Fourteen were randomized to receive treatment for H. pylori eradication and 11 to receive omeprazole alone. There was no difference in the percentage of time the oesophageal pH < 4 before and 26 weeks after treatment among the three groups. However, the percentage of time the oesophageal pH < 2 (P=0.01) and pH < 3 (P=0.02) was significantly increased in patients receiving treatment for H. pylori eradication. Three (21%) patients in the group receiving treatment for H. pylori eradication had worsening of reflux oesophagitis.

CONCLUSIONS

H. pylori eradication increases oesophageal acid exposure and may adversely affect the clinical course of reflux disease in a subset of patients.

Helicobacter pylori and gastrointestinal tract adenocarcinomas

Although gastric adenocarcinoma is associated with the presence of Helicobacter pylori in the stomach, only a small fraction of colonized individuals develop this common malignancy. H. pylori strain and host genotypes probably influence the risk of carcinogenesis by differentially affecting host inflammatory responses and epithelial-cell physiology. Understanding the host-microbial interactions that lead to neoplasia will improve cancer-targeted therapeutics and diagnostics, and provide mechanistic insights into other malignancies that arise within the context of microbially initiated inflammatory states.

Helicobacter pylori infection is associated with a decreased risk of developing oesophageal neoplasms

BACKGROUND

The role of Helicobacter pylori infection in the development of oesophageal malignancies was investigated through a multivariate conditional logistic regression analysis in a nested case-control study.

METHODS

Blood samples and a questionnaire on smoking and alcohol habits were collected from a cohort of 32,906 city residents during a health-screening programme between 1974 and 1992. Forty-four cases of oesophageal cancer and 149 matched controls were selected. The mean interval between screening and cancer diagnosis was 11.9 years. H. pylori seropositivity was determined by an enzyme-linked immunosorbant assay measuring IgG. Occupation was included in the statistical analysis as an indicator of socio-economic status.

RESULTS

Helicobacter pylori seropositivity was present in 10 of the cases (22.7%) and 67 of the controls (45.0%). In a multivariate model, with adjustment for occupation, tobacco and alcohol consumption, the odds ratio for developing an oesophageal malignancy when infected with H. pylori was 0.29 (95% confidence interval (CI): 0.12-0.67). Current smokers had an odds ratio of 17.3 (95% CI: 3.0-99.4) and the odds ratio for ex-smokers was 5.9 (95% CI: 1.15-29.9). High alcohol consumption was no longer significantly associated with oesophageal neoplasms after tobacco smoking was included into the model, odds ratio 1.22 (95% CI: 0.46-3.2). The protective effect of H. pylori was more pronounced for oesophageal adenocarcinoma (seven cases, odds ratio 0.16, 95% CI: 0.00-1.06) than for squamous-cell carcinoma (29 cases, odds ratio 0.41, 95% CI: 0.14-1.2).

CONCLUSIONS

Helicobacter pylori infection is associated with a decreased risk of developing an oesophageal malignancy. Current smokers and ex-smokers have instead a definite increased risk of oesophageal neoplasms.

Helicobacter pylori arginase inhibits nitric oxide production by eukaryotic cells: a strategy for bacterial survival

The antimicrobial effect of nitric oxide (NO) is an essential part of innate immunity. The vigorous host response to the human gastric pathogen Helicobacter pylori fails to eradicate the organism, despite up-regulation of inducible NO synthase (iNOS) in the gastric mucosa. Here we report that wild-type strains of H. pylori inhibit NO production by activated macrophages at physiologic concentrations of l-arginine, the common substrate for iNOS and arginase. Inactivation of the gene rocF, encoding constitutively expressed arginase in H. pylori, restored high-output NO production by macrophages. By using HPLC analysis, we show that l-arginine is effectively consumed in the culture medium by wild-type but not arginase-deficient H. pylori. The substantially higher levels of NO generated by macrophages cocultured with rocF-deficient H. pylori resulted in efficient killing of the bacteria, whereas wild-type H. pylori exhibited no loss of survival under these conditions. Killing of the arginase-deficient H. pylori was NO-dependent, because peritoneal macrophages from iNOS(-/-) mice failed to affect the survival of the rocF mutant. Thus, bacterial arginase allows H. pylori to evade the immune response by down-regulating eukaryotic NO production.

Predominant nocturnal acid reflux in patients with Los Angeles grade C and D reflux esophagitis

BACKGROUND AND AIMS

Nocturnal gastric acid breakthrough (NAB) is defined as an intragastric pH < 4.0 lasting more than 1 h during the night in patients taking a proton pump inhibitor (PPI). Gastroesophageal reflux disease (GERD) patients with nocturnal gastroesophageal acid reflux accompanied by NAB are thought to be refractory to PPI treatment. The aim of this study was to endoscopically identify the patients with predominant nocturnal gastroesophageal acid reflux.

METHODS

The subjects were 37 patients with erosive reflux esophagitis (Los Angeles classification (LA) grade A, 12; B, 10; C, eight; and D, seven cases) and a control group of 20 patients without esophagitis. The results of ambulatory 24 h gastric and esophageal pH monitoring were compared among different grades of esophagitis.

RESULTS

Gastroesophageal reflux during 24 h in patients with high-grade esophagitis was more frequent than for patients with low-grade esophagitis or no esophagitis. Although the length of esophageal acid exposure (percentage time with pH < 4.0) in patients with grade A or without esophagitis was longer in the daytime, that in patients with grades C and D was longer during the night. The reason for the delayed nocturnal acid exposure was the longer nocturnal acid clearance in high-grade reflux esophagitis.

CONCLUSIONS

Nocturnal exposure of the esophagus to acid occurs frequently in patients with LA grades C and D esophagitis. Thus, the existence of NAB with resulting nocturnal acid reflux should be considered when the patient with high-grade esophagitis shows resistance to PPI treatment.

Influence of Helicobacter pylori infection on the prevalence of reflux esophagitis in Japanese patients

BACKGROUND AND AIM

Reflux esophagitis is caused by esophageal motor dysfunction in patients with sufficient gastric acid secretion. Helicobacter pylori causes atrophic gastritis and influences gastric acid secretion. Hiatus hernia (HH) of the esophagus causes motor dysfunction in the lower esophagus. Therefore, this study aimed to test whether H. pylori infection, gastric mucosal atrophy and HH are predictive factors for reflux esophagitis.

METHODS

Helicobacter pylori infection was examined in 781 patients by the measurement of serum immunoglobulin (Ig)G antibody, bacteriological culture and histological examination of biopsy specimens. The prevalence of HH, endoscopically identified gastric mucosal atrophy (closed- or open-type) and reflux esophagitis were investigated by reviewing endoscopic films. Investigated patients were divided into three age groups, under 49, 50-69, and over 70 years. The prevalence of esophagitis, H. pylori infection, gastric mucosal atrophy, and HH were compared to identify the possible predictive factors for reflux esophagitis by using logistic regression analysis.

RESULTS

Sixty-nine patients with reflux esophagitis were found among the 781 investigated cases. The odds ratios of negative H. pylori infection, endoscopically identified closed-type gastric mucosal atrophy, and HH for the prevalence of reflux esophagitis were 1.342, 1.751 and 5.527, respectively. These results indicated that the presence of H. pylori infection was only a weak negative risk factor, and that HH was the most reliable endoscopic predictive factor for reflux esophagitis.

CONCLUSION

Helicobacter pylori infection is a weak negative risk factor for the prevalence of reflux esophagitis, while HH is the most reliable predictive factor.

pathogenesis of Helicobacter pylori-induced gastric inflammation

Helicobacter pylori causes persistent inflammation in the human stomach, yet only a minority of persons harbouring this organism develop peptic ulcer disease or gastric malignancy. An important question is why such variation exists among colonized individuals. Recent evidence has demonstrated that H. pylori isolates possess substantial phenotypic and genotypic diversity, which may engender differential host inflammatory responses that influence clinical outcome. For example, H. pylori strains that possess the cag pathogenicity island induce more severe gastritis and augment the risk for developing peptic ulcer disease and distal gastric cancer. An alternative, but not exclusive, hypothesis is that enhanced inflammation and injury is a consequence of an inappropriate host immune response to the chronic presence of H. pylori within the gastric niche. Investigations that precisely delineate the mechanisms responsible for induction of gastritis will ultimately help to define which H. pylori-colonized persons bear the highest risk for subsequent development of clinical disease, and thus, enable physicians to focus eradication therapy.

The association between CagA status and the development of esophagitis after the eradication of Helicobacter pylori

BACKGROUND

Strains of Helicobacter pylori with the cytotoxine-associated gene A (cagA) are linked to severe forms of gastroduodenal disease. Although eradication of H. pylori may predispose to the development of reflux esophagitis, the effects of CagA status on risk of esophagitis after successful H. pylori treatment are not known.

METHODS

We studied 50 consecutive patients without esophagitis in whom H. pylori was eradicated successfully. CagA status was determined by immunoblotting sera from patients against H. pylori antigens. Patients underwent upper gastrointestinal endoscopy before eradication and 6, 12, 18, and 24 months after eradication or when reflux symptoms occurred. Biopsy specimens of the antrum and corpus were evaluated for gastritis before H. pylori eradication and at the end of the study. The sum of the scores for acute and chronic inflammation (both measured on a 0 [absent] to 3 [severe] scale) comprised the total gastritis severity score.

RESULTS

In a multivariate proportional hazards regression analysis, positive CagA serology (hazard ratio [HR] = 10, 95% confidence interval [CI]: 1.3 to 81) and moderate-to-severe corpus gastritis (total severity score > or =4) before eradication (HR = 2.3, 95% CI: 1.2 to 6.1) were independent risk factors for the development of esophagitis after H. pylori eradication.

CONCLUSION

Patients infected with strains of H. pylori that are cagA-positive are at increased risk of developing esophagitis after eradication of H. pylori.

Pathogenesis of gastroesophageal reflux and Barrett esophagus

Barrett esophagus is a metaplastic condition that affects the lower esophagus and is a complication of gastroesophageal reflux disease (GERD). Under normal circumstances, the reflux of gastric contents into the esophagus is prevented by a complex barrier at the esophagogastric junction. Dysfunction of the lower esophageal sphincter and the presence of a hiatal hernia lead to failure of this barrier. Esophageal mucosal damage results from the chronic exposure of the esophageal mucosa to gastroduodenal contents and the lack of an effective mucosal defense. This article is an overview of the dysfunction of the esophagogastric junction that leads to GERD. The role of the contents of the reflux and that of Helicobacter pylori infection in the pathogenesis of Barrett esophagus are also summarized.

Helicobacter pylori and gastroesophageal reflux disease: lack of influence of infection on twenty-four-hour esophageal pH monitoring and endoscopic findings

The precise role of Helicobacter pylori infection in gastroesophageal reflux disease (GERD) is a matter of intense debate. Twenty-four-hour esophageal pH monitoring has a higher accuracy than endoscopy for the diagnosis of GERD, but the correlation between H. pylori infection and esophageal pH-metric parameters has almost never been assessed. Therefore, we evaluated the relationship between the infection and the presence of disturbances not only in endoscopy but also in 24-hour esophageal pH monitoring. One hundred consecutive patients undergoing 24-hour esophageal pH monitoring because of symptoms suggestive of GERD were included in the study. Esophageal manometry was carried out to study the position and the pressure of the lower esophageal sphincter (LES). Prevalence of H. pylori infection was evaluated by histology (hematoxylin and eosin stain) and rapid urease test. The mean age of the patients was 50 +/- 15 years; 50% were men and 56% had an abnormal pH-metry (DeMeester score more than 14.7). The prevalence of H. pylori in patients with abnormal pH-metry was 57% (95% CI, 42-70%) and was 52% (95% CI, 39-64%) in those with normal pH-metry (nonsignificant differences [NS]). In the multivariate analysis, H. pylori infection did not correlate with an abnormal pH-metry (odds ratio, 0.8; 95% CI, 0.4-1.8; NS). The proportion of cases with abnormal pH-metry among infected patients was 54% (95% CI, 41-66%) and was 59% (95% CI, 44-72%) among uninfected patients (NS). Mean values of pH-metric parameters (+/-SD), respectively for H. pylori-positive and -negative patients, were total score (30 +/- 33 vs. 36 +/- 38), number of reflux episodes (7 +/- 7 vs. 11 +/- 11), number of episodes more than 5 minutes (3.7 +/- 5 vs. 3.8 +/- 5), longest reflux episode (2.4 +/- 2 minutes vs. 3.1 +/- 3 minutes), and fraction time (%) with pH less than 4 (total, 6 +/- 7 vs. 6.8 +/- 8; upright, 3.9 +/- 4 vs. 4.5 +/- 5; supine, 7.4 +/- 12 vs. 7.2 +/- 10) (all findings were NS). Endoscopic findings, respectively for H. pylori-positive and -negative, were hiatus hernia (41% vs. 41%), endoscopic esophagitis (Savary-Miller) (54% vs. 46%), and Barrett's esophagus (15% vs. 11%) (all findings were NS). Finally, differences were not demonstrated in the pressure of the lower esophageal sphincter (12 +/- 8 mmHg vs. 14 +/- 12 mmHg) among H. pylori-positive and -negative patients. H. pylori infection is not associated with gastroesophageal reflux disease, as evaluated endoscopically and with 24-hour esophageal pH monitoring.

Colonization with cagA-positive Helicobacter pylori strains inversely associated with reflux esophagitis and Barrett's esophagus

AIM

The hypothesis that colonization with cagA(+) Helicobacter pylori strains protects against the development of gastroesophageal reflux disease (GERD) and its complications is tested.

METHODS

Patients with reflux esophagitis and Barrett's esophagus were studied. Antral biopsy specimens were obtained for detection of H. pylori. A serum sample was obtained for determination of IgG antibodies to H. pylori and to the CagA protein.

RESULTS

736 patients were studied. 118 patients had reflux esophagitis, 36 had Barrett's esophagus, 108 had hiatal hernia without signs of inflammation (the reflux group), and 20 patients had esophageal or stomach cancer. The remaining 454 patients had no signs of GERD. The 262 patients with reflux disease had a significantly lower prevalence of H. pylori (34.9%) than the 454 controls (54.6%; p<0. 001). Among 310 H. pylori-positive patients from whom serum was available, colonization with cagA(+) strains was detected in 59% in the control group versus 35% in the reflux group (p<0.001).

CONCLUSION

Patients with reflux esophagitis and Barrett's esophagus have a significantly lower prevalence of H. pylori colonization than controls, in particular of the cagA(+) type. These data suggest that colonization with cagA(+) H. pylori strains may be protective against the development of GERD

Pathogenesis of gastroesophageal reflux and Barrett esophagus

Barrett esophagus is a metaplastic condition that affects the lower esophagus and is a complication of gastroesophageal reflux disease (GERD). Under normal circumstances, the reflux of gastric contents into the esophagus is prevented by a complex barrier at the esophagogastric junction. Dysfunction of the lower esophageal sphincter and the presence of a hiatal hernia lead to failure of this barrier. Esophageal mucosal damage results from the chronic exposure of the esophageal mucosa to gastroduodenal contents and the lack of an effective mucosal defense. This article is an overview of the dysfunction of the esophagogastric junction that leads to GERD. The role of the contents of the reflux and that of Helicobacter pylori infection in the pathogenesis of Barrett esophagus are also summarized.