Helicobacter pylori in 205 consecutive endoscopy patients

Non-invasive diagnostic tests for Helicobacter pylori infection

BACKGROUND

Helicobacter pylori (H pylori) infection has been implicated in a number of malignancies and non-malignant conditions including peptic ulcers, non-ulcer dyspepsia, recurrent peptic ulcer bleeding, unexplained iron deficiency anaemia, idiopathic thrombocytopaenia purpura, and colorectal adenomas. The confirmatory diagnosis of H pylori is by endoscopic biopsy, followed by histopathological examination using haemotoxylin and eosin (H & E) stain or special stains such as Giemsa stain and Warthin-Starry stain. Special stains are more accurate than H & E stain. There is significant uncertainty about the diagnostic accuracy of non-invasive tests for diagnosis of H pylori.

OBJECTIVES

To compare the diagnostic accuracy of urea breath test, serology, and stool antigen test, used alone or in combination, for diagnosis of H pylori infection in symptomatic and asymptomatic people, so that eradication therapy for H pylori can be started.

SEARCH METHODS

We searched MEDLINE, Embase, the Science Citation Index and the National Institute for Health Research Health Technology Assessment Database on 4 March 2016. We screened references in the included studies to identify additional studies. We also conducted citation searches of relevant studies, most recently on 4 December 2016. We did not restrict studies by language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We included diagnostic accuracy studies that evaluated at least one of the index tests (urea breath test using isotopes such as 13C or 14C, serology and stool antigen test) against the reference standard (histopathological examination using H & E stain, special stains or immunohistochemical stain) in people suspected of having H pylori infection.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the references to identify relevant studies and independently extracted data. We assessed the methodological quality of studies using the QUADAS-2 tool. We performed meta-analysis by using the hierarchical summary receiver operating characteristic (HSROC) model to estimate and compare SROC curves. Where appropriate, we used bivariate or univariate logistic regression models to estimate summary sensitivities and specificities.

MAIN RESULTS

We included 101 studies involving 11,003 participants, of which 5839 participants (53.1%) had H pylori infection. The prevalence of H pylori infection in the studies ranged from 15.2% to 94.7%, with a median prevalence of 53.7% (interquartile range 42.0% to 66.5%). Most of the studies (57%) included participants with dyspepsia and 53 studies excluded participants who recently had proton pump inhibitors or antibiotics.There was at least an unclear risk of bias or unclear applicability concern for each study.Of the 101 studies, 15 compared the accuracy of two index tests and two studies compared the accuracy of three index tests. Thirty-four studies (4242 participants) evaluated serology; 29 studies (2988 participants) evaluated stool antigen test; 34 studies (3139 participants) evaluated urea breath test-13C; 21 studies (1810 participants) evaluated urea breath test-14C; and two studies (127 participants) evaluated urea breath test but did not report the isotope used. The thresholds used to define test positivity and the staining techniques used for histopathological examination (reference standard) varied between studies. Due to sparse data for each threshold reported, it was not possible to identify the best threshold for each test.Using data from 99 studies in an indirect test comparison, there was statistical evidence of a difference in diagnostic accuracy between urea breath test-13C, urea breath test-14C, serology and stool antigen test (P = 0.024). The diagnostic odds ratios for urea breath test-13C, urea breath test-14C, serology, and stool antigen test were 153 (95% confidence interval (CI) 73.7 to 316), 105 (95% CI 74.0 to 150), 47.4 (95% CI 25.5 to 88.1) and 45.1 (95% CI 24.2 to 84.1). The sensitivity (95% CI) estimated at a fixed specificity of 0.90 (median from studies across the four tests), was 0.94 (95% CI 0.89 to 0.97) for urea breath test-13C, 0.92 (95% CI 0.89 to 0.94) for urea breath test-14C, 0.84 (95% CI 0.74 to 0.91) for serology, and 0.83 (95% CI 0.73 to 0.90) for stool antigen test. This implies that on average, given a specificity of 0.90 and prevalence of 53.7% (median specificity and prevalence in the studies), out of 1000 people tested for H pylori infection, there will be 46 false positives (people without H pylori infection who will be diagnosed as having H pylori infection). In this hypothetical cohort, urea breath test-13C, urea breath test-14C, serology, and stool antigen test will give 30 (95% CI 15 to 58), 42 (95% CI 30 to 58), 86 (95% CI 50 to 140), and 89 (95% CI 52 to 146) false negatives respectively (people with H pylori infection for whom the diagnosis of H pylori will be missed).Direct comparisons were based on few head-to-head studies. The ratios of diagnostic odds ratios (DORs) were 0.68 (95% CI 0.12 to 3.70; P = 0.56) for urea breath test-13C versus serology (seven studies), and 0.88 (95% CI 0.14 to 5.56; P = 0.84) for urea breath test-13C versus stool antigen test (seven studies). The 95% CIs of these estimates overlap with those of the ratios of DORs from the indirect comparison. Data were limited or unavailable for meta-analysis of other direct comparisons.

AUTHORS' CONCLUSIONS

In people without a history of gastrectomy and those who have not recently had antibiotics or proton ,pump inhibitors, urea breath tests had high diagnostic accuracy while serology and stool antigen tests were less accurate for diagnosis of Helicobacter pylori infection.This is based on an indirect test comparison (with potential for bias due to confounding), as evidence from direct comparisons was limited or unavailable. The thresholds used for these tests were highly variable and we were unable to identify specific thresholds that might be useful in clinical practice.We need further comparative studies of high methodological quality to obtain more reliable evidence of relative accuracy between the tests. Such studies should be conducted prospectively in a representative spectrum of participants and clearly reported to ensure low risk of bias. Most importantly, studies should prespecify and clearly report thresholds used, and should avoid inappropriate exclusions.

Helicobacter pyloriinfection and its correlation to extraesophageal and esophageal reflux in contact granuloma patients

To evaluate the presence of Helicobacter pylori (H. pylori) infection and its correlation to extraesophageal and esophageal reflux, 18 consecutive contact granuloma patients were examined by laryngoscopy, 24-hour double probe pH monitoring and [13C]-urea breath test. Sixteen of the 18 patients (89%) were H. pylori-negative, while 2 patients (11%) showed positive test results. Extraesophageal reflux was detected in 14 patients; one of them was H. pylori-positive. In the ten patients with abnormal distal esophageal reflux, one was H. pylori-positive. The present results do not confirm increased prevalence for H. pylori infection in contact granuloma patients and the occurrence of H. pylori infection was not correlated to the amount of pharyngeal or esophageal acid exposure.

Efficacy of the natural antioxidant astaxanthin in the treatment of functional dyspepsia in patients with or without Helicobacter pylori infection: A prospective, randomized, double blind, and placebo-controlled study

OBJECTIVES

The aim of this study was to evaluate the efficacy of the natural antioxidant astaxanthin in functional dyspepsia in different doses and compared with placebo.

DESIGN

The study was a controlled, prospective, randomized, and double blind trial.

PARTICIPANTS

Patients with functional dyspepsia, divided into three groups with 44 individuals in each group (placebo, 16mg, or 40mg astaxanthin, respectively).

INTERVENTIONS

Participants were asked to accept gastroscopy before treatment, together with questionnaires: GSRS and SF-36. Urea breath test (UBT) was done before the treatment.

MAIN OUTCOME

The primary objective was to test the hypothesis that the antioxidant astaxanthin at two doses regimens compared to placebo should ameliorate gastrointestinal discomfort measured as GSRS in patients with functional dyspepsia, who were either positive or negative for Helicobacter pylori, after 4 weeks of treatment.

RESULTS

At the end of therapy (week 4) no difference between the three treatment groups was observed regarding mean Gastrointestinal Symptom Rating Scale (GSRS) scores of abdominal pain, indigestion and reflux syndromes. The same results were observed at the end of follow-up. However reduction of reflux syndrome before treatment to week 4 was significantly pronounced in the higher (40mg) dose compared to the other treatment groups (16mg and placebo, p=0.04).

CONCLUSION

In general, no curative effect of astaxanthin was found in functional dyspepsia patients. Significantly greater reduction of reflux symptoms were detected in patients treated with the highest dose of the natural antioxidant astaxanthin. The response was more pronounced in H. pylori-infected patients.

H pylori infection and reflux oesophagitis: A case-control study

AIM: To examine the relationship between H pylori and gastro-oesophageal reflux disease (GORD) in Iran.

METHODS: In this study 51 GORD patients (referred to endoscopy at Taleghani hospital) were compared with 49 age-sex matched controls. Diagnosis of H pylori was made by gastric mucosal biopsy and rapid urease test (positive if the result of one or both diagnostic methods was positive). Updated Sydney system was used to report histopathological changes.

RESULTS: The frequency of H pylori infection based on rapid urease test and histology was 88.2% (45) in patients and 77.6% (38) in controls, which showed no significant difference. The frequency of H pylori infection was significantly higher in the antrum than in the corpus and cardia. The mean activity, inflammation, and gastritis scores were also higher in the antrum of patients than in the antrum of controls. The mean scores were significantly higher in the corpus of controls than in the corpus of patients. Diffuse active gastritis was observed in a significantly larger number of controls, while the frequency of diffuse chronic gastritis was higher in patients. There was no significant difference in the frequency of other histological findings between patients and controls.

CONCLUSION: H pylori infection cannot prevent GORD in this region.

Extensive intestinal metaplasia in gastric carcinoma and in other lesions requiring surgery: a study of 3,421 gastrectomy specimens from dwellers of the Atlantic and Pacific basins

BACKGROUND

Extensive intestinal metaplasia (EIM) has been reported in gastrectomies from patients dwelling in the Pacific and Atlantic basins.

AIMS

To compare all the results in an attempt to explain the findings.

METHOD

All sections from 3,421 gastrectomies were reviewed at various hospitals: 1946 in the Atlantic and 1475 in the Pacific basin. Sections with EIM showed IM encompassing one or more entire low power field (>or=5 mm in length/section) in one or more section.

RESULTS

In the Atlantic basin, EIM was present in 18.8% (153 of 814) of specimens with intestinal carcinoma (IC) and in 10.3% (65 of 630) of those with diffuse carcinoma (DC). In the Pacific basin, EIM was found in 62.9% (412 of 655) of gastrectomies with IC and in 33.3% (160 of 481) of those with DC. The numbers of specimens with EIM were significantly higher in the Pacific than in the Atlantic basin for both carcinoma phenotypes, particularly among elderly patients (>or=60 years).

CONCLUSIONS

The proportion of gastrectomies with EIM was higher among populations at a higher gastric cancer risk than in those with a lower cancer risk. EIM was mostly associated with IC rather than DC or with miscellaneous gastric diseases (841 control gastrectomies) in both basins. The proportion of gastrectomies with EIM was significantly higher in Vancouver than in New York and in Santiago de Chile than in Buenos Aires, even though these populations reside at approximately the same geographical latitude, but in different basins. Environmental factors seem to accelerate the evolution of EIM.

Long-term effects of eradication of Helicobacter pylori on relapse and histology in gastric ulcer patients: a two-year follow-up study

BACKGROUND

The main purpose of this study was to compare omeprazole (ome) plus two antibiotics (OMC) with omeprazole plus placebo (OP) with regard to gastric ulcer relapse for a period of 2 years in patients who were Helicobacter pylori-positive at inclusion.

METHODS

Using double-blind randomization 125 patients with gastric ulcer were treated with either OMC (ome 20 mg b.i.d., metronidazole 400 mg b.i.d., clarithromycin 250 mg b.i.d.) (n = 64) or OP (ome 20 mg and placebo) (n = 61) for 1 week, followed by ome 20-40 mg o.d. until healing was confirmed endoscopically after 4, 8 or 12 weeks. Endoscopy and H. pylori diagnostics using culture, histology and serology were performed 6, 12 and 24 months after treatment or at symptomatic relapse. At inclusion, 35% of the OMC group and 38% of the OP group were taking non-steroidal anti-inflammatory drugs (NSAIDs). Nine percent (11/125) of the ulcers were malignant.

RESULTS

The prevalence of H. pylori was 82% and the eradication rate 88% in the OMC group and 3% in the OP group. More than 90% of the ulcers were healed after 12 weeks. After 2 years, 76% of patients in the OMC group were in remission compared with 28% in the OP group (ITT) (P < 0.001). Sixty percent of patients in the OMC group that continued to take NSAIDs were in remission after 2 years compared with none in the OP group. Atrophy but not intestinal metaplasia decreased after treatment.

CONCLUSIONS

Gastric ulcers are mainly caused by H. pylori, and relapse is effectively prevented by H. pylori eradication, even in patients on NSAIDs.

Enzyme-linked immunosorbent assay for Helicobacter pylori needs adjustment for the population investigated

Helicobacter pylori infection and peptic ulcer disease are common in developing countries, e.g., Vietnam. An enzyme-linked immunosorbent assay (ELISA) for screening of patients and for seroepidemiology is a useful tool but needs to be validated in the population studied. We used in-house ELISA with sonicated Swedish and Vietnamese strains as antigens to measure immunoglobulin G antibodies after absorption with sonicated Campylobacter jejuni in sera from 270 H. pylori culture-confirmed peptic ulcer patients, 128 Swedish urea-breath test and immunoblot-positive healthy controls, and 432 Vietnamese immunoblot-positive population controls. Sonicated whole-cell antigen based on the local strains showed a significantly better performance. Immunoblot-positive peptic ulcer patients had significantly higher antibody concentrations than immunoblot-positive population controls, necessitating a lower cutoff level if serology is used for screening or epidemiological purposes. The study shows that the parameters of ELISA for H. pylori need to be adjusted for the population being investigated.

Relationship of gastric Helicobacter pylori infection to Barrett’s esophagus and gastro-esophageal reflux disease in Chinese

AIM: To evaluate the relationship of Helicobacter pylori infection to reflux esophagitis (RE), Barrett’s esophagus (BE) and gastric intestinal metaplasia (IM).

METHODS: RE, BE and gastric IM were determined by upper endoscopy. Patients were divided into 2 groups; those with squamocolumnar junction (SCJ) beyond gastroesophageal junction (GEJ) ≥ 3 cm (group A), and those with SCJ beyond GEJ < 3 cm (group B). Biopsy specimens were obtained endoscopically from just below the SCJ, gastric antrum along the greater and lesser curvature. Pathological changes and H pylori infection were determined by HE staining, Alcian blue staining and Giemsa staining.

RESULTS: The prevalence of H pylori infection was 46.93%. There was no difference in the prevalence between males and females. The prevalence of H pylori infection decreased stepwise significantly from RE grade I to III. There was no difference in the prevalence between the two groups, and between long-segment and short-segment BE. In distal stomach, prevalence of H pylori infection was significantly higher in patients with IM than those without IM.

CONCLUSION: There is a protective role of H pylori infection to GERD. There may be no relationship between H pylori infection of stomach and BE. H pylori infection is associated with the development of IM in the distal stomach.

Unexpected decrease with age of Helicobacter pylori seroprevalence among Swedish blood donors

Blood donors are often used as proxies for the general population in studies of Helicobacter pylori epidemiology. Our aim was to test if the age-specific seroprevalence rates among blood donors match with the corresponding rates in a random population sample. This descriptive study was based on sera obtained from 3,502 blood donors representing all Swedish counties and cities. An age-stratified random population sample of 1,030 from Stockholm County served as comparison. Sera were analyzed by an in-house enzyme-linked immunosorbent assay for H. pylori immunoglobulin G antibodies. In the population sample, we found the expected increase with age in the seroprevalence of H. pylori infection. This was true also among young blood donors, while the prevalence-by-age curve showed a deflection downward among blood donors who are >/= 50 years of age. In this age group, the probability of being seropositive was reduced by 73% (95% confidence interval [CI], 63 to 81%) relative to the population sample. Overall, the adjusted odds ratio for H. pylori seropositivity among blood donors was decreased by 43% (95% CI, 28 to 55%). Thus, it appears that blood donors who are H. pylori seropositive selectively disappear from the blood donor cohort. We speculate that H. pylori-seropositive blood donors may tolerate repeated bleedings less well than do noninfected individuals and/or that the general well-being among those who are infected may be somewhat impaired. Our unexpected observation indicates that blood donors may be less suitable as proxies for the general population in analytic studies of H. pylori infection and that the underlying cause needs further study.

Effect of Helicobacter pylori infection in Barrett's esophagus and the genesis of esophageal adenocarcinoma

The relation between Helicobacter pylori and gastroesophageal reflux disease is unclear. Recent reports have suggested a possible protective role for H. pylori, particularly in preventing the complications of gastroesophageal reflux disease (GERD). The purpose of this article is to present a brief overview of the recent literature regarding the role of H. pylori in the genesis of the complications of GERD, focusing on Barrett's esophagus and esophageal adenocarcinoma. The prevalence of H. pylori infection in the population of the West is around 40% and is not different in cohorts of patients with GERD. When the infection induces pangastritis or corpus-predominant gastritis, there may be concomitant reduced gastric acid secretion. Eradication of the bacteria in this subgroup of patients may enhance gastric acid secretion and provoke reflux symptoms. H. pylori organisms do not colonize the specialized intestinal metaplasia characteristic of Barrett's esophagus. H. pylori infection rates in gastric mucosa of patients with Barrett's esophagus occur at a similar or slightly lower frequency than is found in controls. Gastric infection with cagA-positive strains of H. pylori appears to be uncommon in patients with Barrett's esophagus. Furthermore, epidemiologic studies indicate that cagA-positive strains are protective against esophageal adenocarcinoma. Several investigators have proposed that the decreasing prevalence of H. pylori infection might be an important factor in the rising incidence of this tumor.

Helicobacter pylori-induced duodenal ulcer frequently coincides with gastro-oesophageal reflux disease

BACKGROUND

The relationship between Helicobacter pylori infection and gastro-oesophageal reflux disease is complicated. Evidence does not support a causal link. There have been reports, which have implicated successful eradication of Helicobacter pylori, in patients with a duodenal ulcer, with the subsequent development of gastro-oesophageal reflux disease. However, eradication of Helicobacter pylori in these patients with improvement in their condition and a return to normal lifestyle, weight gain and discontinuation of antacids may unmask pre-existing gastro-oesophageal reflux disease.

AIMS

To determine the true prevalence of gastro-oesophageal reflux disease in patients with Helicobacter pylori-related duodenal ulceration.

METHOD

Dyspeptic patients undergoing endoscopy were prospectively screened for the presence of a duodenal ulcer. Concomitant oesophagitis, when present, was recorded. All subjects with a Helicobacter pylori-related duodenal ulcer without endoscopic evidence of gastro-oesophageal reflux disease were invited to undergo a 24-hr ambulatory oesophageal pH assessment prior to receiving treatment.

RESULTS

A total of 97 patients with a duodenal ulcer were identified and 83.5% were Helicobacter pylori positive. Overall, 27.8% had associated endoscopic evidence of oesophagitis, 70% grade I-II and 30% grade III-IV. Of those without evidence of oesophagitis at endoscopy, 68% underwent a 24-hr pH assessment. An additional 17% were identified by this means as having gastro-oesophageal reflux disease. Overall, 44% of symptomatic subjects with Helicobacter pylori and a duodenal ulcer were found to have coexistent gastro-oesophageal reflux disease.

CONCLUSION

Gastro-oesophageal reflux disease is frequently found to coexist with Helicobacter pylori-related duodenal ulcer. In addition, almost 20% of symptomatic patients without endoscopic evidence of oesophagitis will have an abnormal oesophageal pH exposure. It is plausible that the development of gastro-oesophageal reflux disease following successful eradication of Helicobacter pylori represents unmasking of existing disease rather than de novo development.

Review article: the cost of diagnosing Helicobacter pylori infection

Non-invasive testing and treatment for Helicobacter pylori has been recommended for dyspeptic patients in primary care and a number of recent studies have demonstrated the cost-effectiveness of this approach. As the prevalence of H. pylori infection declines, the positive and negative predictive values of individual tests will change. Cost-effectiveness is important in determining the appropriate test in individual populations. Recent studies have shown that the stool antigen test and the urea breath test have high sensitivity and specificity in the detection of H. pylori infection before and after therapy. Cost-effectiveness studies have shown that when the prevalence of H. pylori infection is low or intermediate, serological tests have relatively poor accuracy compared with the stool test or the urea breath test. In populations with low or intermediate prevalence (<60%) these tests should be preferred to ELISA serology or office-based whole-blood test or serology. This is particularly true when the prevalence of H. pylori infection is less than 30% as is seen in many developed countries. When the prevalence of H. pylori infection is high (>60%), low-cost antibody tests are cost-effective.

The accuracy of serologic diagnosis of Helicobacter pylori infection in school-aged children of mixed ethnicity

The present study evaluated two non-invasive diagnostic methods for H. pylori infection in children, i.e. an in-house ELISA using sonicated Campylobacter jejuni antigen for absorption of cross-reacting antibodies and an immunoblot kit (Helico Blot 2.0, Genelabs, Singapore). 13C -Urea breath test (13C-UBT) was used as reference

METHOD

Sera and questionnaires were collected from 695/858 (81%) Swedish school children with mixed ethnic backgrounds within a cross-sectional, community-based study. Of 133 children with an ELISA OD value of > or = 0.1, all were screened with immunoblot and 107 made a 13C-UBT. The negative controls were 34/37 children from three school classes with an ELISA OD value of < 0.1 and volunteering for a 13C-UBT. An adjusted cut-off level for the ELISA of OD value 0.22 resulted in a sensitivity of 97.8%, a specificity of 95.8% and a concordance index of 97.2%. The Helico Blot 2.0 had a sensitivity of 97.8%, a specificity of 93.8% and a concordance index of 96.5%. The best concordance was seen for the 26.5 kDa (98.6%), 30 kDa (95.7%) and 19.5 kDa (91.5%) antigens. The corresponding concordance index for CagA was 78%, for VacA 73.8% and for the 35kDa antigen 68.8%. A significant difference in the distribution of the 19.5 and 26.5 kDa bands but not of CagA/VacA was noted by ethnic background. With an adjusted cut-off level for the enzyme-linked immunosorbent assay (ELISA), both non-invasive methods were found to have an adequate performance in a pediatric population. The differences in antibody response patterns by ethnic background represent a caveat in the interpretation of serological studies.

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.

Curing Helicobacter pylori infection in patients with duodenal ulcer does not provoke gastroesophageal reflux disease

BACKGROUND

It has been suggested that the incidence of gastroesophageal reflux disease (GERD) increases after successful eradication of Helicobacter pylori infection. We present data on development of GERD from a controlled study of H. pylori eradication in 165 duodenal ulcer patients.

METHODS

Patients (mean age, 55 years; 102 men; current smokers; n = 74) were randomly assigned 2: 1 to receive omeprazole, 40 mg twice daily, in combination with either amoxicillin, 750 mg twice daily, or placebo. Endoscopy and dyspeptic symptoms, including heartburn, were assessed at inclusion and at 6, 12, and 24 months after treatment. In addition, symptoms were assessed at 18 months. Patients with erosive esophagitis or reflux symptoms requiring treatment at inclusion were not included in the study.

RESULTS

Fifty-one of 145 (35%) evaluable patients developed heartburn, and 13 of 145 (9%) developed esophagitis during follow-up. The life-table analysis of the cumulated risk of developing heartburn showed that patients whose H. pylori infection was eradicated had a significantly lower risk for developing heartburn than those with persistent H. pylori infection. The groups did not show any difference in cumulative risk of developing esophagitis.

CONCLUSION

Our data show that successful eradication of H. pylori infection does not increase the incidence of GERD in duodenal ulcer patients.

What have we learned from recent dyspepsia trials?

Dyspepsia is a common disorder and a frequent complaint of patients presenting for primary care. Understanding of the role of Helicobacter pylori has led to re-evaluation of management strategies for these patients. This article highlights results from clinical trials that have helped to clarify the role of empiric therapy, endoscopy, radiography, and H. pylori eradication in patients with nonulcer dyspepsia.

Omeprazole and CYP2C19 polymorphism: effects of long-term treatment on gastrin, pepsinogen I, and chromogranin A in patients with acid related disorders

BACKGROUND

The polymorphic enzyme CYP2C19 is of importance for the metabolism and effects of omeprazole during short-term treatment.

AIM

To investigate the relationship between CYP2C19 genotype and the effects of long-term omeprazole treatment.

MATERIAL AND METHODS

A total of 180 patients with acid related disorders were genotyped for wild type and mutated CYP2C19 alleles by allele-specific PCR amplification. Gastrin and chromogranin A were assessed by radioimmunoassays, and pepsinogen I and H. pylori serology were assessed by ELISA methods.

RESULTS

In 108 of the patients, who received a single dose of 20 mg omeprazole, there was no difference in gastrin and chromogranin A concentrations between the three CYP2C19 genotypes. In 72 patients on long-term treatment (> 1 year) with 20 mg omeprazole daily, serum gastrin as well as plasma chromogranin A concentrations (mean +/- s.e.) were both about threefold higher in the wild type/mutated (52.1 +/- 7.6 pM and 7.3 +/- 1.3 nM (n=19), respectively) compared to wild type/wild type (14. 7 +/- 0.9 pM and 2.5 +/- 0.1 nM (n=52), respectively; both comparisons P=0.0001). In a single mutated/mutated patient on long-term treatment, both gastrin and chromogranin A were high (88 pM and 13.7 nM, respectively). Serum pepsinogen I concentration was significantly lower in wild type/mutated (n=19) patients on long-term treatment, compared with the corresponding wild type/wild type (n=49) group (147 +/- 19 microg/L vs. 193 +/- 12 microg/L, P=0. 04).

CONCLUSION

Patients with one (and probably also with two) mutated CYP2C19 allele(s) on long-term treatment with omeprazole had significantly affected serum gastrin and pepsinogen I and plasma chromogranin A concentrations compared with patients with two normal alleles. This indicates that changes in gastric mucosal morphology during omeprazole treatment might be dependent upon the degree of the individual's capacity to metabolize omeprazole.

Relationship between intestinal metaplasia of the gastro-oesophageal junction, Helicobacter pylori infection and gastro-oesophageal reflux disease: a prospective study

BACKGROUND

The role of Helicobacter pylori infection and/or gastro-oesophageal reflux disease in pathogenesis of intestinal metaplasia in gastric cardia is still unclear.

AIMS

To prospectively evaluate prevalence of inflammation and intestinal metaplasia of cardia in relationship to Helicobacter pylori infection in patients with gastro-oesophageal reflux disease and in healthy controls.

PATIENTS

A total of 122 consecutive patients with gastro-oesophageal reflux disease and 49 control subjects were included.

METHODS

During endoscopy, a total of six biopsies were taken from antrum, corpus and cardia. Helicobacter pylori infection was assessed by histology and rapid urease test. Degree of chronic gastritis, inflammatory activity and Helicobacter pylori colonization were scored from 0 to 3.

RESULTS

No difference in prevalence was observed between gastro-oesophageal reflux disease patients and controls as far as concerns Helicobacter pylori (41% vs 38%), inflammation of cardia (59.5% vs 70%) and intestinal metaplasia of cardia (18% vs 19%). Inflammation of cardia was significantly (p<0.001) associated with Helicobacter pylori irrespective of gastro-oesophageal reflux disease symptoms. Cardial intestinal metaplasia was more frequently (p=0.03) found in infected subjects ((27%) than in uncolonized subjects (13%). No relationship was observed between gastro-oesophageal reflux disease and carditis and cardial intestinal metaplasia. Cardial intestinal metaplasia was more frequently detected in association with carditis (26% vs 6%, p=0.001).

CONCLUSIONS

Inflammation and intestinal metaplasia of the gastric cardia are not markers of gastro-oesophageal reflux disease but are related to Helicobacter pylori.

Effects of omeprazole on intragastric pH and plasma gastrin are dependent on the CYP2C19 polymorphism

BACKGROUND & AIMS

Omeprazole is metabolized by cytochrome P450 (CYP2C19). The activity of this enzyme is polymorphic, with incidences of poor metabolizers (PMs), heterozygous extensive metabolizers (EMs), and homozygous EMs in white populations of 3%, 30%, and 67%, respectively. The importance of the CYP2C19 polymorphism for the effects of omeprazole on intragastric pH and plasma gastrin concentrations has been investigated.

METHODS

Twenty-five white patients were genotyped for CYP2C19 by allele-specific polymerase chain reaction amplification, and their Helicobacter pylori status was assessed by serology and with immunoblot analysis. Intragastric pH was monitored over 24 hours, and meal-stimulated plasma gastrin concentration was measured over 4 hours (AUC 4h) before (day 0) and during (day 8) treatment with 20 mg omeprazole once daily.

RESULTS

Eleven patients were homozygous for the wild-type allele (wt/wt), 12 were heterozygous EMs (wt/mut), and 2 were PMs (mut/mut). Median (95% confidence interval) 24-hour intragastric pH in the heterozygous EM group was 5.5 (range, 5.1-5. 9) compared with 3.1 (range, 2.7-3.6) in homozygous EMs (P < 0.0001) at day 8. The percentage of time with intragastric pH > 4 at day 8 was significantly higher in the wt/mut than wt/wt group (72.4% vs. 37.1%; P < 0.0001). H. pylori status had less influence than CYP2C19 on intragastric acidity. Omeprazole treatment increased meal-stimulated plasma gastrin concentrations from day 0 to day 8 in the homozygous EMs and heterozygous EMs by 16% (NS) and 157% (P = 0. 002), respectively. In heterozygous EMs, the gastrin increase was more pronounced in the H. pylori-positive group (226%) than H. pylori-negative group (80%; P = 0.02).

CONCLUSIONS

The effects of omeprazole on intragastric pH and plasma gastrin are dependent on the CYP2C19 polymorphism in patients with acid-related disorders.

The cost-effectiveness of diagnostic testing strategies for Helicobacter pylori

OBJECTIVE

Several noninvasive methods are now available for diagnosing Helicobacter pylori infection. Because the prevalence of H. pylori infection is variable in patients requiring testing, the optimal testing strategies may vary under different conditions. The aim of this study was to evaluate the cost-effectiveness of competing diagnostic strategies for H. pylori in patients with varying H. pylori prevalence.

METHODS

A decision analysis was performed comparing the costs per number of correct diagnoses achieved by alternative sequential testing strategies. Estimates of H. pylori prevalence and test characteristics were derived from a systematic review of the MEDLINE bibliographic database. Cost estimates were derived from the 2000 Medicare Fee Schedule.

RESULTS

The enzyme-linked immunosorbent assay (ELISA) test had the lowest cost per correct diagnosis at low (30%), intermediate (60%), and high (90%) prevalence ($90-$95/correct diagnosis), but its diagnostic accuracy was low (80-84%). At low and intermediate prevalence the stool test was more accurate (93%), with an average cost of $126-$127 per correct diagnosis. Additional confirmatory testing of positive or negative tests increased the diagnostic accuracy of the stool test, but had high incremental costs. ELISA testing was preferable when prevalence rates were very high (90%), and using a confirmatory urea breath test for negative ELISA tests increased the diagnostic accuracy to 96%, with modest incremental costs. If the cost of the breath test was <$50 or if the cost of the stool test is >$82, breath testing became preferable to stool testing. If the cost of the stool test fell to <$20, it became preferable to ELISA. Similarly, if the cost of the ELISA serology was >$39 then stool testing became preferable at all prevalence rates. Fingerstick whole blood tests were not cost-effective.

CONCLUSIONS

The choice of an initial test for H. pylori detection depends on the prevalence of H. pylori infection and the value placed on increased diagnostic accuracy. Although ELISA results in the lowest cost-effectiveness ratios, in patients at low-intermediate pretest probability of infection, the stool test provides increased accuracy, with modest incremental costs.

Helicobacter pylori and gastroesophageal reflux disease

The nature of the relationship between Helicobacter pylori (Hp) infection and gastroesophageal reflux disease (GERD) remains unclear. This article reviews the current body of knowledge regarding the association between these two common entities. The authors examine the potential interactions of Hp and GERD from epidemiologic and pathophysiologic viewpoints and summarize and critique the prevalence and eradication studies that have been performed to date. Special consideration is given to the possible effects that long-term use of proton pump inhibitors may have on Hp gastritis.

Helicobacter pylori: the Middle East scenario

A review of Helicobacter pylori in the Middle East is presented. Prevalence studies have been performed in asymptomatic population groups from Algeria, Israel, Saudi Arabia and Turkey. These showed that the prevalence of H. pylori is similar to that of the developing countries of the world with a high level of infection in childhood (40 to 70 percent), which increases with age to 85 to 90 percent. Israel, however, has a low prevalence in children (10 percent), but there is a rapid rise in the second decade of life to 39 percent, reaching 79 percent in those over 60 years old. The prevalence rates were higher in those living in communal settlements (72 percent) than in urban dwellers (65 percent). The infection rates were higher in persons of Mediterranean and Asian origin (89 percent) compared to those of Western European/North American origin (57 percent). The prevalence rate of H. pylori infection in patients undergoing endoscopy for upper gastrointestinal symptoms has now been reported from many Middle Eastern countries, including Egypt, Iran, Israel, Oman, Saudi Arabia, the United Arab Emirates and Yemen. These studies showed that patients with gastritis and peptic ulcer disease had similar rates of infection as reported from Europe, United States and Africa (71 to 92 percent). However, patients with non-ulcer dyspepsia had higher rates of infection (61 to 89 percent). The H. pylori scenario from the prevalence rates, treatment protocols and responses to treatment does not differ very much from other developing areas of the world.

Review article: Helicobacter pylori and gastro-oesophageal reflux disease-clinical implications and management

A significant proportion of patients with gastro-oesophageal reflux disease (GERD) have Helicobacter pylori infection, but it is unclear whether or not H. pylori should be treated in this clinical setting. The aim of this review was to critically assess the relationship between H. pylori and GERD and its potential implications for the management of GERD. Data for this review were gathered from the following sources up to April 1998-the biomedical database MEDLINE, a detailed review of medical journals, and a review of abstracts submitted to relevant international meetings. On average, 40% of GERD patients carry H. pylori infection, with a reported infection prevalence ranging from 16% to 88%. To date, there has been no reported controlled trial of effective H. pylori therapy in GERD. GERD has been reported to develop de novo following the cure of H. pylori in peptic ulcer disease. In the presence of H. pylori, proton pump inhibitor therapy appears to accelerate the development of atrophic corpus gastritis, a potentially precancerous condition. Conversely, proton pump inhibitor therapy seems to become less effective after cure of H. pylori. The mechanisms underlying these important contrasting phenomena are poorly understood. The relationship between H. pylori and GERD is complex, and it is difficult to give definitive guidelines on the management of H. pylori infection in GERD. Controlled trials of H. pylori therapy in GERD are urgently needed, as well as further long-term data on both the natural history of gastric histopathological changes in the H. pylori-positive GERD patient treated with proton pump inhibitors, and the impact of H. pylori status on the clinical efficacy of antisecretory therapy. Pending these data, it is perhaps advisable to advocate cure of H. pylori in young patients with proton pump inhibitor-dependent GERD who, in the absence of anti-reflux surgery, are faced with the likelihood of long-term medical therapy.

CYP2C19 genotype and phenotype determined with omeprazole in patients with acid-related disorders with and without Helicobacter pylori infection

BACKGROUND

Omeprazole is to a major extent metabolized by cytochrome P450 isozyme CYP2C19. The aims of this study were to compare the phenotype of CYP2C19 determined by omeprazole with the genotype and to determine the effect of Helicobacter pylori infection on the metabolism of omeprazole.

METHODS

One-hundred and forty-three Caucasian patients with acid-related disorders assessed with a combination of gastrointestinal symptoms and upper endoscopic findings were given 20 mg omeprazole orally. Three hours after intake, omeprazole and 5-hydroxyomeprazole plasma concentrations were determined with high-performance liquid chromatography, and the phenotype for metabolic capacity was expressed as metabolic ratio (MR). Genotyping of defect alleles (CYP2C19*2 and *3) was performed by polymerase chain reaction amplification. One hundred eleven patients were tested after the first dose of omeprazole and 32 patients after repetitive administration (median time, 30 days). H. pylori serology was determined with enzyme-linked immunosorbent assay at the time of phenotyping.

RESULTS

Genotypically, 2.8% had two mutated alleles and were poor metabolizers (PM), and 22.4% were heterozygous extensive metabolizers (EM). Among the 111 patients who received the first omeprazole dose, 4 patients had MR >5--that is, belonged to the PM phenotype. Two of these had PM genotype (both CYP2C19*2/*2), and two had an EM genotype (CYP2C19*11*1 and *1/*3), indicating that they have still unidentified mutations. In the heterozygous EM group the mean MR was higher in patients who had been on continued omeprazole treatment than in those given the first dose (5.7 versus 2.5, P = 0.02). There were no significant differences in MR and omeprazole concentrations between H. pylori-negative (43%) and -positive (57%) patients.

CONCLUSION

In all but two patients with probable unidentified mutations there was agreement between the CYP2C19 phenotype determined by omeprazole and the genotype. The metabolism of omeprazole in patients with acid-related disorders is genetically determined and without relation to H. pylori infection.

Helicobacter pylori infection, reflux esophagitis, and atrophic gastritis: an unexplored triangle

OBJECTIVE

H. pylori causes chronic gastritis, which may progress to peptic ulcer, gastric atrophy, or gastric cancer. However, little is known about the role of H. pylori infection in reflux esophagitis and the relationship between reflux esophagitis and atrophic gastritis needs to be clarified. We sought to identify the possible interrelationships among Helicobacter pylori infection, reflux esophagitis, and atrophic gastritis, to signal areas in which researchers should consider focusing their attention.

METHODS

A broad-based Medline search was performed to identify all related publications addressing H. pylori infection, atrophic gastritis, gastroesophageal reflux disease (GERD), secretion of gastric acid, and gastric motility published between 1966 and July 1997.

RESULTS

Whereas some studies have shown no significant association between H. pylori infection and reflux esophagitis, others have observed that the prevalence of H. pylori infection was lower in patients with GERD, implying a protective role. Eradication of H. pylori leads to occurrence of reflux esophagitis in some cases, but the mechanisms inducing posteradication reflux esophagitis are unknown. H. pylori infection may lead to atrophic gastritis (and hence hypochlorhydia) through both bacterial and host factors, although gastric atrophy and subsequent intestinal metaplasia are hostile to H. pylori because of hypochlorhydria. Although it has been reported that long-term proton pump inhibitor therapy for refractory reflux esophagitis may induce or enhance the development of gastric atrophy in H. pylori-infected patients, this relationship has been disputed.

CONCLUSIONS

H. pylori infection may be negatively associated with reflux esophagitis, but this requires confirmation. Research then needs to focus on whether this is explained through motility- or acid-related mechanisms. The potential costs of maintenance antireflux therapy may need to be taken into account when evaluating the cost effectiveness of anti-H. pylori therapy.

Evaluation and comparison of two immunodiagnostic assays for Helicobacter pylori antibodies with culture results

Several commercially available serological kits have been used as an alternative to endoscopy for the diagnosis of Helicobacter pylori infection. We evaluated the performance of two such kits, Serion H. pylori immunotab kit (Serion, Wurzberg, West Germany) and Pyloragen H. pylori test kit (Hypcor Biomedical Inc., Irvine, CA). Gastric biopsy and serum samples were collected from 345 consecutive dyspeptic patients. The culture and or direct smear of the biopsy was positive for H. pylori in 228 patients (66%), whereas 117 patients (34%) were found to be H. pylori negative. We determined the serological response of the patients using the two kits, both of which are based on the principle of enzyme-linked immunosorbent assay. Comparing the serum immunoglobin G (IgG) and IgA (in a limited number of cases) responses to H. pylori status, the sensitivity, the specificity, positive predictive value, and negative predictive value were calculated. The corresponding data for the different tests were 64%, 79%, 84%, and 56% for Serion IgC, 32%, 94%, 88%, and 52% for Serion IgA, and 88%, 17%, 62%, and 46% for Pyloragen IgG, respectively. We conclude that there is a poor correlation between the presence of H. pylori infection and the antibody response, which could be explained either because of low sensitivities and specificities of the commercial kits used for the measurement of antibodies to H. pylori in the serum or because of poor immunological response in our patients to H. pylori antigens.

Hyperplastic foveolar gastropathies and hyperplastic foveolar gastritis

Thirteen gastrectomy specimens having diffuse (n = 5), focal (i.e., nodular, n = 6) or combined (n = 2) giant hypertrophic folds at gross examination were reviewed. Of the five specimens with grossly diffuse hypertrophic fundic mucosal folds, two had at histology tortuous foveolar hyperplasia (without intraepithelial lymphocytosis) and prominent glandular cysts; they were classified as Ménétrier's gastropathy. The other three specimens with diffuse foveolar hyperplasia had serrated foveolar infoldings with marked intraepithelial lymphocytosis; they were classified as Ménétrier-like lymphocytic gastritis. Of the six, specimens with multiple mucosal nodules at gross examination, four had focal foveolar hyperplasia with crest depression and no intraepithelial lymphocytosis; they were classified as varioliform gastropathy. The other two specimens with multiple nodules at gross examination had focal foveolar hyperplasia with marked intraepithelial lymphocytosis; they were classified as varioliform gastritis. In the remaining two cases, both diffuse and nodular hypertrophic gastric mucosa were found at gross examination; at histology, both foveolar hyperplasia and intraepithelial lymphocytosis were found. The diffuse or focal distribution of the lesions, the occurrence of intraepithelial lymphocytosis and the architecture of the upper part of the crypts (in diffuse foveolar hyperplasias) were valuable criteria in the differential diagnosis between the various types of foveolar hyperplasia of the stomach.

Seroepidemiology of Helicobacter pylori infection in a cohort of children monitored from 6 months to 11 years of age

A cohort of Swedish children was monitored from 6 months to 11 years of age. Immunoglobulin G (IgG) and IgA antibodies to Helicobacter pylori were measured in 1,857 serum samples, drawn at the ages of 6, 8, 10, 18 months and 2, 4, and 11 years. Of the 294 children, 40 (13.6%) were found to have been infected at some time. However, at 11 years of age, only 6 of 201 (3%) children were seropositive. The highest seroprevalence of positive results, 10%, was found at 2 years of age, and the highest incidence of 13.3% could be calculated for the period between 18 months and 2 years of age. There were no confirmed additional cases for children between 4 and 11 years of age. Infection with H. pylori thus occurs at an early age in a developed country (as well as in developing countries), and spontaneous clearance seems to be common.

The diagnostic value of enzyme immunoassay and immunoblot in monitoring eradication of Helicobacter pylori

55 patients with severe ulcer disease and H. pylori infection, successfully treated with antimicrobials, were followed-up with repeated blood samples for up to 32 months. Sera were analysed by enzyme immunoassay (EIA) for IgG and IgA antibodies and by IgG immunoblot. The EIA for IgG antibodies showed a high sensitivity (100%), while IgA antibodies above the cut-off level were found in 55% of the patients. At a median of 77 days after onset of treatment, approximately 50% of the patients showed a significant decrease (> or = 50%) of IgG or had titres below the cut-off level. All patients but 1 had a significant decrease of IgG after 6-12 months. The decrease was slower for IgA. The H. pylori-specific 116 kDa and 19.5 kDa bands were found in all pre-treatment samples, but the decrease in median intensity of the bands was slower than for the IgG EIA. In the 32-months post-treatment samples, both bonds had an intensity still above 50% of the pre-treatment value. The study showed that the IgG EIA is a useful method for monitoring eradication of H. pylori. Immunoblot can detect previous H. pylori infection in EIA negative Individuals.

Use of a receiver operating characteristic in the evaluation of two commercial enzyme immunoassays for detection of Helicobacter pylori infection

Two novel commercial IgG enzyme immunoassay (EIA) systems based on acid-glycine-extracted (Pyloriset IgG EIA, Orion Diagnostica) or fast protein liquid chromatography-purified (Cobas Core Anti-H. pylori EIA, Roche Diagnostic Systems) Helicobacter antigens were evaluated in a prospective study involving 127 patients. All patients underwent upper endoscopy with biopsy, and biopsies were examined for the presence of Helicobacter pylori by a rapid urease test, microscopy and culture. Of the 71 patients found to be infected with Helicobacter pylori, 69 (97.2%) and 65 (91.5%) tested positive with the Cobas Core and Pyloriset test, respectively. A detailed receiver operating characteristic analysis of the two tests showed that the Cobas Core assay was more sensitive and specific at every possible cut-off level; gave a better resolution of individual results, indicating a greater fine-sensitivity; and had no grey zone compared to a large grey zone encompassing 13.4% of the serum samples tested with the Pyloriset EIA. The Cobas Core assay appears to be a valuable tool for epidemiological purposes as well as for pre-endoscopic screening of dyspeptic patients.

Evaluation of a new immunodiagnostic assay for Helicobacter pylori antibody detection: correlation with histopathological and microbiological results

Infection with Helicobacter pylori has been associated with the pathogenesis of chronic active gastritis and gastric and duodenal ulcer disease. Detection of immunoglobulin G antibodies to H. pylori offers a simple alternative to direct detection of the organism in biopsied tissue by culture or histopathological methods. A rapid flow-through membrane-based enzyme immunoassay for the detection of human immunoglobulin G antibodies to H. pylori has been developed and evaluated. Clinical evaluations were performed with 256 patient serum samples obtained from four clinical sites. Biopsy samples were obtained by endoscopic procedures at the same time as the serum samples, and were histopathologically and microbiologically categorized for the presence or absence of H. pylori. Sensitivity and specificity for this rapid enzyme immunoassay were 92 and 88%, respectively, compared directly with endoscopy results. After discordant results were resolved by a quantitative microwell enzyme-linked immunosorbent assay, the resulting sensitivity and specificity were 94 and > 99%, respectively. These results indicate that this rapid enzyme immunoassay is a useful technique to determine H. pylori infection status and is a viable alternative to invasive endoscopic procedures.