Introduction
Helicobacter pylori (H. pylori) infection is a well-known etiological factor for many gastrointestinal diseases, such as chronic gastritis, peptic ulcer disease, mucosa-associated lymphoid tissue lymphoma, and gastric cancer. The gastric inflammation due to H. pylori may be antral-predominant gastritis, closely associated with duodenal ulceration, whereas corpus-predominant gastritis is associated with an increased risk of gastric cancer, though H. pylori atrophic gastritis affects both antral or corpus mucosa (multifocal atrophic gastritis). Eradication of H. pylori infection is recommended to prevent and/or treat these diseases. In addition, there are many important issues to be elucidated regarding the role of H. pylori in very severe pathologies such as esophageal cancer and other more benign disorders, common in the developed world, such as gastro-esophageal reflux disease (GERD), which carry a significant impact on health economics, and patient morbidity. In this respect, symptoms like heartburn, acid regurgitation, and dysphagia are usually sufficient to confirm the diagnosis of GERD and initiate treatment. The most common test used to confirm excessive GERD is ambulatory 24-h esophageal pH monitoring; although this test cannot be regarded as a definitive gold standard for GERD diagnosis, it is indicated in several clinical situations defined by national or expert groups. The main limitation of the 24-h pH monitoring is its low tolerability [1]; patients report that pH testing frequently induces unpleasant side effects lasting for most of the day. Thus, a shorter monitoring period may be more tolerable [2].
To our knowledge, there are no data regarding the evaluation of the effect of H. pylori eradication in GERD patients, by using the 3-h postprandial esophageal pH monitoring. Therefore, the aim of this study was to evaluate the effect of H. pylori eradication in a Greek cohort with H. pylori-positive GERD, by using the 3-h postprandial esophageal pH monitoring, as a more flexible test for evaluating this disease.
Patients and methods
Patients
Due to protocol, by introducing mainly the 3-h postprandial esophageal pH monitoring, we enrolled patients who had erosive esophagitis at endoscopy and H. pylori infection at histology, successfully cured following eradication therapy. Specifically, the selected H. pylori-positive patients had weekly reflux symptoms for at least six months. The twenty-nine selected H. pylori-positive patients who were eligible underwent esophageal manometry and ambulatory 3-h postprandial esophageal pH monitoring at baseline and 3-months post-H. pylori eradication regimen; successful eradication of H. pylori was observed in all 29 selected H. pylori-positive patients, confirmed by 13C urea breath test (UBT) at 4-week post-treatment period. All participants provided informed consent. The study protocol conformed to the ethical guidelines of the 1975 Declaration of Helsinki and was approved by the local ethics committee.
Exclusion criteria for the GERD patients were: any past history of gastric or esophageal surgery; suspected or confirmed malignant disease; previous H. pylori eradication regimens; anticoagulant treatment; esophageal ring stricture or esophagitis secondary to systemic diseases (e.g. scleroderma or ingested irritants); primary esophageal motility disorders; pregnancy or lactation; and age <18 years old. Patients with endoscopic evidence of active gastrointestinal bleeding and those with Zollinger-Ellison’s syndrome were also excluded from the study. All patients had stopped acid suppression therapy (4 days beforehand for those taking antacids and 20 days beforehand for those using H2-receptor antagonists or proton pump inhibitors) and underwent a 4-week washout period during which any medications known to affect gastrointestinal motility, like tricyclic antidepressants, were tapered. None of the patients was receiving oral medication that could cause or deteriorate GERD symptoms [3].
Endoscopy
All 29 selected patients were seen at 9 a.m. after a 12-h fast. Intravenous sedation was given, and standard upper gastrointestinal endoscopy, using the Fujinon EPX-201 endoscopy system (Fujinon Optical Tokyo, Japan), was performed to identify evidence of macroscopic abnormalities. The degree of reflux esophagitis was graded from A (least severe) to D (most severe) according to the Los Angeles classification system. Two biopsy specimens were obtained from the antral region within 2 cm of the pyloric ring from each patient. One biopsy specimen was used for rapid urease slide testing of H. pylori infection (CLOtest) and the other biopsy specimen was placed in 10% formalin and submitted for histological examination to look for H. pylori organisms on Giemsa staining; the diagnosis of H. pylori infection was confirmed by histology.
Manometry and 3-h postprandial pH-monitoring study
All 29 patients were reviewed for baseline manometry and 3-h postprandial pH monitoring within 3 days. After an overnight fast esophageal manometry was performed using a 4-channel, silicone rubber, low compliance, pneumohydraulic-perfused manometric assembly without a sleeve sensor (Manometric pump-model PIP-4-8SS Mui Scientific). The manometric assembly was passed transnasally and the position of the lower esophageal sphincter (LES) was determined using the station pull-through technique at 0.5 cm intervals. Manometric examination of the LES also served as a guide for the correct placement of the pH-sensitive probe. After removal of the manometric catheter, a monocrystalline antimony pH catheter was passed transnasally and the electrode was positioned 5 cm above the proximal margin of the LES. The electrode was calibrated in buffers of pH 7 and pH 4 before each study (pHmetry UPS 2020, MMS- Medical Measurement Systems BV). The 3-h postprandial ambulatory esophageal pH monitoring study was then carried out. Patients were encouraged to avoid coffee, alcohol, fruit juices, and antacids. They were also encouraged to take their meal at the same time during the 3-h period. They were however instructed to proceed with their normal daily routine. The same meals were used during the second pH recording to minimize day-to-day pH variation. Data acquisition was performed using a portable solid-state data logger. The pH data were analyzed by a standard software programme. The start of a reflux episode was defined by an esophageal pH below the threshold of 4.0 and its end by an esophageal pH above 4.0. Parameters of esophageal acid exposure, including the DeMeester score, were then calculated for the 3-h postprandial period by standard software programme. All analyses were performed by a single investigator (J.M.). Abnormal GERD, or a positive test, was defined as pH<4 in the distal esophagus for more than 4% of the total recording time and DeMeester score >14.72 [4]. The DeMeester score, used as the basis for correlation between the subjects, was calculated for the 3-h postprandial period by a standard software program. The DeMeester score is a complex index that takes into account the percentage of total time with pH<4, pH<4 in upright position, pH<4 in supine position, the number of reflux episodes with intra-esophageal pH<4, the number of reflux episodes with intra-esophageal pH<4 with duration over 5 min and the reflux episode with the greatest duration in min.
H. pylori eradication regimen
All 29 H. pylori infected patients received the 10-day regimen including use of rabeprazole 20 mg, amoxicillin 1 g, and clarithromycin 500 mg b.i.d. for 10 days, followed by rabeprazole 20 mg q.d. for another 30 days. Subsequently, the 13C UBT was used to confirm H. pylori eradication at 4-week post-treatment period, thereby avoiding false negative UBT results if rabeprazole was not suspended 4 weeks before performing the test. Manometry and 3-h postprandial pH-monitoring studies were also repeated at a 3-month post-treatment period (~20 days post-UBT period) to define any changes in these parameters, following H. pylori eradication.
Statistical analysis
Statistical analysis was performed using the SPSS for Windows package (version 11.0, SPSS, Chicago, IL, USA). Data were presented as means ± SD, means with 95% CI or median values with 5th and 95th percentiles when appropriate. Wilcoxon’s rank test was used to detect differences between baseline and 3-month H. pylori post-eradication period. For categorical variables, differences in frequencies were studied using the Fisher’s exact test. Significance was set at P<0.05.
Results
All 29 selected patients had endoscopically established Grade A or B esophagitis according to the Los Angeles classification system. Moreover, according to protocol, all 29 patients received successful H. pylori eradication therapy, as confirmed by UBT at 4-week post-treatment period.
Post-eradication, 18 out of 29 H. pylori positive patients (62.1%) showed the same manometric pattern as baseline; 5 patients (17.2%) showed improvement (propagation of esophageal peristalsis, pressure of LES); 5 patients (17.2%) normalization; and 1 patient (3.4%) deterioration of the manometric patterns (Table 1).
Table 1
Post-eradication manometric pattern in Helicobacter pylori-positive patients with gastro-esophageal reflux disease (GERD)
The overall DeMeester score in the 3-h postprandial ambulatory esophageal pH monitoring improved after eradication of H. pylori (median 47.47 vs. 22.00, Wilcoxon’s singed rank; P=0.016) (Fig. 1). Specifically, on comparing the pH monitoring studies for each patient prior and after successful H. pylori eradication, 24 of 29 patients (82.8%) showed improvement; and 5 of 29 the patients (17.2%) showed deterioration of the DeMeester score. Moreover, 9 of the 24 (37.5%) patients with improved pH monitoring study, during the post-eradication period showed completely normal pHmetry (DeMeester score <14.72) post-treatment.
Figure 1
DeMeester score at baseline and 4-week post-eradication period in 29 Helicobacter pylori-infected patients with gastro-esophageal reflux disease. Bold horizontal lines express median values, boxes represent interquartile range
Discussion
To our knowledge, this is the first study aiming to evaluate the effect of H. pylori eradication in a cohort with GERD, by using 3-h postprandial esophageal pH monitoring; three months after successful eradication of H. pylori there was significant improvement in the severity of acid reflux, as judged by established criteria. Although analysis of esophageal and stomach acidity is the best method of studying the pathogenesis of GERD, it is difficult to perform 24-h pH monitoring in a large number of patients, due to poor compliance. We therefore used the 3-h postprandial pH monitoring study as a sensitive and mainly more flexible method; the overall DeMeester score in the 3-h postprandial ambulatory esophageal pH monitoring was significantly improved with a concomitant improvement in pH monitoring after eradication of H. pylori in our patients.
To our knowledge, four relative studies exist in the literature comparing GERD before and after H. pylori eradication by using 24-h pH monitoring.
Verma et al [5], aimed to assess the prevalence of GERD before and after H. pylori eradication by using 24-h esophageal pH/manometry studies. Patients were followed up at 6 months and 1 year when they underwent a repeat 24-h pH/manometry; 20 patients were enrolled, though only 10 patients attended for a repeat 24-h pH/manometry study. H. pylori eradication: a) had no impact on percentage of time pH <4 and DeMeester Score; and b) induced no substantial changes in LES pressure and other esophageal manometry data. It is important to note that new onset GERD occurred very unusually one year after H. pylori eradication [5].
Tefera et al [6], expected that H. pylori eradication might increase GERD in reflux esophagitis patients, because increased prevalence of esophagitis has been reported following eradication of H. pylori. Twenty-five consecutive patients with H. pylori infection were enrolled; 24-h intra-esophageal pH recording was performed before and 12 weeks after eradication. H. pylori eradication, also confirmed by 13C UBT, induced no consistent change in gastro-esophageal acid reflux.
Manifold et al [7] studied 25 patients with H. pylori gastritis using 24-h esophageal and gastric pHmetry and gastric bilirubin monitoring before and after H. pylori eradication, also confirmed by 13C UBT. No differences were noticed in esophageal acid reflux, gastric alkaline exposure, or gastric bilirubin exposure before and after eradication. The authors concluded that H. pylori eradication induces no change in GERD or duodenogastric reflux.
Wu et al [8] also studied 25 patients with H. pylori erosive esophagitis using 24-h esophageal pHmetry. They concluded that H. pylori eradication increases esophageal acid exposure and might adversely affect the clinical course of disease in 21% of patients.
Differences in populations enrolled and methodologies might explain, at least partly, the discrepancies of our own and Verma’s, Tefera’s, Manifold’s, and Wu’s findings. Nevertheless, our and Verma’s data indicate that H. pylori eradication might protect against GERD development [9].
In this regard, H. pylori infection is frequent in Greek patients with GERD and even with non-endoscopic reflux disease and H. pylori eradication leads to better control of GERD symptoms and improves esophagitis [10]. Moreover, consistent associations with the Greek data were shown by others [11], also reporting improvement in reflux symptoms following H. pylori treatment. It is important to note that some other authors, usually prior supporters of the theory that H. pylori “protects” against GERD, relented their initial findings, claiming that H. pylori eradication does not cause or protect against GERD, and, moreover, recommending H. pylori eradication in GERD [12]. Additionally, although epidemiologic studies do not suggest causality with H. pylori, however, such studies support our and others’ findings; for instance, a large study (~21,000 cases) showed that the decrease in H. pylori infection parallels the decrease in peptic ulcer prevalence, and the increase in GERD and reappearance of GERD after H. pylori eradication is rare [8], also reported by Verma et al [5]. Much evidence further potentiates the concern that H. pylori is not “protective” against GERD [13].
The interplay between H. pylori and host factors plays an important role in the pathogenesis of GERD. Specifically, H. pylori may contribute to GERD pathogenesis by several mechanisms including the release of several mediators, cytokines and nitric oxide (NO) which may adversely affect the LES; cause direct damage of the esophageal mucosa by bacterial products; increase production of prostaglandins that sensitize afferent nerves and reduce LES pressure; and augment acidity (by gastrin release) that exacerbates GERD [10,14]. Specifically, there is the concept that gastric inflammation at the cardia may lower the threshold for transient relaxationof the LES by altering the sensitivity of vagal sensory receptors [15]. H. pylori gastritis is accompanied by release of the abovementioned NO, cytokines and prostaglandins that promote damage to the adjacent esophageal mucosa [16]. There is good evidence to indicate that the excessive production of prostaglandins in reflux esophagitis drives a vicious cycle of LES dysfunction, reflux, mucosal inflammation, aggravated LES dysfunction and further reflux. Moreover, the predominantly antral H. pylori gastritis is associated with an augmented gastrin release; increased acidity along with a higher volumeof gastric juice may aggravate reflux disease. Finally, in a recent critical review [17] regarding the complicated data available on the topic of H. pylori association with GERD, the authors concluded that: Intra-esophageal pH recording data fail to confirm increased acid reflux following H. pylori eradication; esophageal manometric studies suggest that bacterial eradication reduce rather than favor acid reflux into the esophagus; clinical studies suggest that H. pylori eradication is not considerably associated with reflux symptoms or erosive esophagitis onset; and some data also suggest an advantage in curing the infection when esophagitis is already present.
The present series have certain limitations: 1) the sample size, though the biggest in the relevant literature, was rather small, given that even the introduction the 3-h postprandial esophageal pH monitoring is not always easily acceptable by the patients; 2) the missed patients with a persistent H. pylori infection may preclude assessing whether the observed pH-recording modifications are definitely due to the bacterial loss; and 3) only 1 biopsy specimen was used for histology. This is an inadequate sampling protocol for routine endoscopic practice; 5 biopsies (2 antrum, 1 angulus, 2 corpus) being advised by current guidelines for an accurate upper endoscopy. However, due to large number of patient recruitment to find our selected H. pylori positive GERD patients, we were obliged to take only 1 instead of 5 biopsies for many obvious reasons mainly including the time burden of histological evaluation.
In conclusion, this study shows that H. pylori eradication may positively influence GERD symptoms. However, large-scale controlled relative studies are warranted to evaluate these findings in depth.
Summary Box
What is already known:
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The most common test used to confirm gastro-esophageal reflux disease (GERD) is ambulatory 24-h esophageal pH monitoring, though characterized by a low tolerability
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Intra-24-h esophageal pH recording data rather fail to confirm increased acid reflux following Helicobacter pylori (H. pylori) eradication
What the new findings are:
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By using the 3-h postprandial esophageal pH monitoring as a more flexible method, this study showed, for the first time, that H. pylori eradication may positively influence GERD symptoms