Role of Helicobacter pylori infection in gastroduodenal injury and gastric prostaglandin synthesis during long term/low dose aspirin therapy: a prospective placebo-controlled, double-blind randomized trial

Helicobacter pylori eradication for primary prevention of peptic ulcer bleeding in older patients prescribed aspirin in primary care (HEAT): a randomised, double-blind, placebo-controlled trial

BACKGROUND

Peptic ulcers in patients receiving aspirin are associated with Helicobacter pylori infection. We aimed to investigate whether H pylori eradication would protect against aspirin-associated ulcer bleeding.

METHODS

We conducted a randomised, double-blind, placebo-controlled trial (Helicobacter Eradication Aspirin Trial [HEAT]) at 1208 primary care centres in the UK, using routinely collected clinical data. Eligible patients were aged 60 years or older who were receiving aspirin at a daily dose of 325 mg or less (with four or more 28-day prescriptions in the past year) and had a positive C13 urea breath test for H pylori at screening. Patients receiving ulcerogenic or gastroprotective medication were excluded. Participants were randomly assigned (1:1) to receive either a combination of oral clarithromycin 500 mg, metronidazole 400 mg, and lansoprazole 30 mg (active eradication), or oral placebo (control), twice daily for 1 week. Participants, their general practitioners and health-care providers, and the research nurses, trial team, adjudication committee, and analysis team were all masked to group allocation throughout the trial. Follow-up was by scrutiny of electronic data in primary and secondary care. The primary outcome was time to hospitalisation or death due to definite or probable peptic ulcer bleeding, and was analysed by Cox proportional hazards methods in the intention-to-treat population. This trial is registered with EudraCT, 2011-003425-96.

FINDINGS

Between Sept 14, 2012, and Nov 22, 2017, 30 166 patients had breath testing for H pylori, 5367 had a positive result, and 5352 were randomly assigned to receive active eradication (n=2677) or placebo (n=2675) and were followed up for a median of 5·0 years (IQR 3·9-6·4). Analysis of the primary outcome showed a significant departure from proportional hazards assumptions (p=0·0068), requiring analysis over separate time periods. There was a significant reduction in incidence of the primary outcome in the active eradication group in the first 2·5 years of follow-up compared with the control group (six episodes adjudicated as definite or probable peptic ulcer bleeds, rate 0·92 [95% CI 0·41-2·04] per 1000 person-years vs 17 episodes, rate 2·61 [1·62-4·19] per 1000 person-years; hazard ratio [HR] 0·35 [95% CI 0·14-0·89]; p=0·028). This advantage remained significant after adjusting for the competing risk of death (p=0·028) but was lost with longer follow-up (HR 1·31 [95% CI 0·55-3·11] in the period after the first 2·5 years; p=0·54). Reports of adverse events were actively solicited; taste disturbance was the most common event (787 patients).

INTERPRETATION

H pylori eradication protects against aspirin-associated peptic ulcer bleeding, but this might not be sustained in the long term.

FUNDING

National Institute for Health and Care Research Health Technology Assessment.

[Helicobacter pylori Eradication in Drug-related Peptic Ulcer]

Non-steroidal anti-inflammatory drugs (NSAIDs) and aspirin are the most frequently prescribed drugs worldwide, and their long-term use often leads to peptic ulcers (PUs) along with serious complications, such as bleeding and perforation. Helicobacter pylori (H. pylori) infection is a significant risk factor for developing NSAID-related PU and ulcer bleeding during long-term aspirin use. In a revised version of the Clinical Guidelines for Drug-induced Peptic Ulcer, two statements regarding H. pylori eradication are recommended. 1) Patients scheduled for long-term NSAID therapy should be tested and treated for H. pylori infection to prevent PU and its complications. 2) Patients with a history of PU receiving long-term low-dose aspirin (LDA) therapy should undergo treatment for H. pylori infection to prevent PU and its complications. On the other hand, unlike NSAID-naïve patients, the preventive effects of H. pylori eradication in chronic NSAID users are unclear. In addition, anti-ulcer drugs, such as proton pump inhibitors, may be necessary for maintenance therapy after H. pylori eradication in a subset of long-term LDA users, particularly if the patients are taking concomitant antiplatelet agents or anticoagulants.

Helicobacter pylori and low-dose aspirin ulcer risk: A meta-analysis

BACKGROUND AND AIM

Owing to wide-spread use, low-dose aspirin (LDA) produces a substantial amount of peptic ulcer disease. Current guidelines are ambivalent about the need for Helicobacter pylori eradication to protect against LDA ulcers. This study aimed to determine, through meta-analysis, if (and by how much) infection alters the baseline risk of peptic ulcers during LDA therapy.

METHODS

Literature screening was performed in MEDLINE and EMBASE from inception to May 2018. Original studies reporting prevalence or incidence of uncomplicated ulcers in LDA users were included. Ulcer endpoints needed to be specified separately, according to H. pylori infection status. Meta-analysis was performed in MIX 2.0 Pro.

RESULTS

Ten cross-sectional studies and seven randomized controlled trials were included (n = 5964). The pooled odds ratios with 95% confidence intervals (CI) for the risk of LDA ulcers in H. pylori-positive versus H. pylori-negative individuals were 1.68 (95%CI 1.40-2.02) and 1.65 (95%CI 1.29-2.08) under fixed-effects and random-effects models, respectively. Heterogeneity among studies was minimal (I²  = 26.9%). After adjusting for the protective effects of antisecretory drugs, the odds ratios increased to 1.94 (95%CI 1.54-2.46).

CONCLUSION

This analysis suggests that H. pylori increases the risk of LDA ulcers by almost 70% in a population where some were taking proton pump inhibitors and/or other acid suppressants. Without antisecretory drugs, the risk almost doubles. Clinically, these findings may support the use of a test-and-treat approach to H. pylori in LDA users, particularly those already at higher risk of developing peptic ulcers.

Increased susceptibility of aging gastric mucosa to injury and delayed healing: Clinical implications

In this editorial we comment on the article by Fukushi K et al published in the recent issue of the World Journal of Gastroenterology 2018; 24(34): 3908-3918. We focus specifically on the mechanisms of the anti-thrombotic action of aspirin, gastric mucosal injury and aging-related increased susceptibility of gastric mucosa to injury. Aspirin is widely used not only for the management of acute and chronic pain and arthritis, but also importantly for the primary and secondary prevention of cardiovascular events such as myocardial infarcts and strokes. Clinical trials have consistently shown that antiplatelet therapy with long term, low dose aspirin (LDA) - 75 to 325 mg daily, dramatically reduces the risk of non-fatal myocardial infarcts, stroke and mortality in patients with established arterial diseases. However, such treatment considerably increases the risk of gastrointestinal (GI) ulcerations and serious bleeding by > 2-4 fold, especially in aging individuals. This risk is further increased in patients using LDA together with other antiplatelet agents, other nonsteroidal anti-inflammatory agents (NSAIDs) and/or alcohol, or in patients with Helicobacter pylori (H. pylori) infection. Previous studies by our group and others have demonstrated prominent structural and functional abnormalities in gastric mucosa of aging individuals (which we refer to as aging gastric mucosa or “aging gastropathy”) compared to the gastric mucosa of younger individuals. Aging gastric mucosa has impaired mucosal defense, increased susceptibility to injury by a variety of noxious agents such as aspirin, other NSAIDs and ethanol, and delayed and impaired healing of injury. The mechanism underlying these abnormalities of aging gastric mucosa include reduced mucosal blood flow causing hypoxia, upregulation of PTEN, activation of pro-apoptotic caspase-3 and caspase-9, and reduced survivin (anti-apoptosis protein), importin-α (nuclear transport protein), vascular endothelial growth factor, and nerve growth factor. The decision regarding initiation of a long-term LDA therapy should be made after a careful consideration of both cardiovascular and GI risk factors. The latter include a previous history of GI bleeding and/or ulcers, age ≥ 70, male gender, concurrent use of other NSAIDs, alcohol consumption and H. pylori infection. Furthermore, the incidence of GI ulcers and bleeding can be reduced in patients on long term LDA treatment by several measures. Clinicians treating such patients should test for and eradicate H. pylori, instruct patients to avoid alcohol and non-aspirin NSAIDs, including cyclooxygenase-2-selective NSAIDs, and prescribe proton pump inhibitors in patients on LDA therapy. In the future, clinicians may be able to prescribe one of several potential new drugs, which include aspirin associated with phosphatidylcholine (PL2200), which retains all property of aspirin but reduces by approximately 50% LDA-induced GI ulcerations.

Geographic differences in low-dose aspirin-associated gastroduodenal mucosal injury

Aspirin, even at low doses, has been known to cause upper gastro-intestinal complications, such as gastroduodenal ulcers, despite the definite benefits from its antithrombotic effects. Helicobacter pylori (H. pylori) is major pathogen responsible for gastroduodenal ulcer formation. There have been conflicting results about the potential interaction between these two ulcerogenic factors and the geographic areas involved. In Western countries, the prevalence of gastroduodenal ulcers is consistently higher in H. pylori-positive low-dose aspirin (LDA) users than in H. pylori-negative ones, suggesting that H. pylori infection exacerbates LDA-induced gastroduodenal mucosal injury in these geographic areas. Meanwhile, previous studies from Japan have generally reported a similar prevalence of LDA-induced gastroduodenal mucosal injury regardless of the presence of H. pylori infection, indicating that the infection is not an overall exacerbating factor for drug-induced injury. H. pylori infection could have a synergistic or antagonistic interaction with LDA use in adverse gastroduodenal events depending on gastric acid secretion. It is well-recognized that the net effect of H. pylori infection on gastric acid secretion shows considerable geographic variation at the population level. While gastric acid secretion levels were not decreased and were well-preserved in most patients with H. pylori infection from Western countries, the majority of Japanese patients with H. pylori infection exhibited decreased gastric acid secretion. Such large geographic differences in the net effect of H. pylori infection on gastric acid secretion could be at least partly responsible for the geographically distinct interaction between LDA use and H. pylori infection on adverse gastroduodenal lesions.

Increased gastric mucus secretion alleviates non-steroidal anti-inflammatory drug-induced abdominal pain

Non-steroidal anti-inflammatory drugs (NSAIDs) can cause dyspeptic symptoms, including abdominal pain. Gastric mucus is important as the first line of defense against luminal irritants. In the present study, we investigated whether gastric mucus secretion could influence the severity of gastric mucosal injuries or NSAID-induced dyspeptic symptoms. Fifteen Helicobacter pylori-negative, healthy males were administered two types of NSAIDs, a non-selective cyclooxygenase inhibitor, naproxen (300 mg, twice a day), or a cyclooxygenase-2-selective inhibitor, etodolac (200 mg, twice a day), for 1 week in a crossover study, with an interval of ≥ 4 weeks. Study participants underwent endoscopic examinations before and after treatment. Pentagastrin-stimulated gastric secretions were collected for 10 min during endoscopic examinations, and were analyzed for gastric acid levels (mEq/10 min) and mucus output (mg hexose/10 min). The grade of gastric mucosal injury was assessed endoscopically. Among 29 subjects who completed the crossover study, 11 individuals reported abdominal pain following the administration of naproxen or etodolac for 1 week, as judged by elevated pain scores, while 18 individuals did not report abdominal pain. The occurrence of symptoms was not associated with the type of NSAIDs administered or the occurrence of erosive injury visualized by endoscopy. Gastric mucus secretion was significantly increased in subjects without drug-induced abdominal pain (P < 0.05), whereas it was significantly reduced in those with drug-induced abdominal pain (P < 0.05). In conclusion, the occurrence of NSAID-induced abdominal pain is associated with reduced levels of gastric mucus secretion rather than the occurrence of endoscopic mucosal injury.

[Antiplatelet therapy with acetylsalicylic acid: approaches to reducing the frequency of gastrointenstinal adverse reactions]

Acetylsalicylic acid (ASA) is highly effective in preventing cardiovascular events, but associated with increased risk for digestive adverse reactions. The paper provides an update on the epidemiology, mechanisms, and risk factors of esophagogastroduodeno- and enteropathies during long-term low-dose ACA therapy. It outlines the key principles of their prevention.

Reactive increase in gastric mucus secretion is an adaptive defense mechanism against low-dose aspirin-induced gastropathy

BACKGROUND

Gastric mucus is considered to play an essential role in gastric mucosal defense mechanisms, especially when irritants are present in the stomach.

AIM

To investigate the relationship between low-dose aspirin-induced gastropathy and gastric secretory function, especially gastric mucus secretion, in healthy volunteers.

METHODS

Thirty male, asymptomatic, Helicobacter pylori pylori-negative healthy volunteers were asked to take 100 mg of enteric-coated aspirin (Bayaspirin) once a day for 10 days. Endoscopic examination was performed before and 3 and 10 days after drug administration. The extent of endoscopically assessed gastric mucosal injury was semi-quantitatively evaluated according to the modified Lanza score. The pentagastrin-stimulated gastric juice was collected for 10 min during the endoscopic examination and subjected to analysis for gastric acid (mEq/10 min) or mucus (mg hexose/10 min) output.

RESULTS

Overall, the 10-day aspirin treatment significantly increased gastric mucus secretion from 0.8 (interquartile range 1.7) to 1.6 (1.6) mg hexose/10 min (P < 0.05), with a concomitant and significant decrease in the gastric acid/mucus ratio from 4.3 (5.2) to 2.9 (4.7) (P < 0.01). Subsequent analysis of two subgroups of volunteers categorized according to their endoscopic status ("severe gastropathy" vs. "modest gastropathy") revealed that changes in gastric secretory parameters occurred exclusively in those subjects without severe gastric injury; there was no alteration in these parameters in subjects with severe gastric injury.

CONCLUSIONS

The results of this study suggest that the reactive increase in gastric mucus secretion is an adaptive defense mechanism against low-dose aspirin-induced gastropathy. In some individuals, such a response may be insufficient to prevent the development of severe mucosal injury and even ulcers and their complications.

Biphasic effects of H. pylori infection on low-dose aspirin-induced gastropathy depending on the gastric acid secretion level

BACKGROUND

The association of Helicobacter pylori infection with aspirin-induced gastropathy is controversial. H. pylori infection exerts diverse effects on gastric acid secretion. In this study, the interaction between H. pylori infection and aspirin was investigated with reference to the individual gastric acid secretion level in H. pylori-positive subjects.

METHODS

Ninety-three (81 men, mean age: 70 years) long-term low-dose aspirin takers were prospectively enrolled. H. pylori infection was evaluated by serum IgG antibody determination, and gastrin-stimulated acid output was assessed with the endoscopic gastrin test. H. pylori-positive aspirin-takers were classified into 2 subgroups (hyposecretors and non-hyposecretors). The grade of gastric mucosal injury was assessed endoscopically according to the modified Lanza score; intensive aspirin-induced gastropathy was defined as a modified Lanza score of ≥4. Multiple logistic regression analyses were used to adjust for potential confounders.

RESULTS

With H. pylori-negative patients taken as the reference, H. pylori infection was found to be positively associated with intensive gastropathy among non-hyposecretors, with an odds ratio (OR) (95 % confidence interval [CI]) of 4.2 (1.1-17.1), while the infection was negatively associated with gastropathy among hyposecretors, with an OR (95 % CI) of 0.3 (0.08-0.9). Aspirin-induced gastropathy occurred preferentially in the antrum among H. pylori-positive non-hyposecretors, while it affected the fundus among H. pylori-positive hyposecretors.

CONCLUSION

The effect of H. pylori infection on the aspirin-induced gastropathy was biphasic depending on the individual gastric acid secretion level. In the presence of sufficient amounts of gastric acid, H. pylori infection and aspirin could synergistically damage gastric mucosal integrity, while in the absence of sufficient amounts of gastric acid, the synergistic effect could be completely counteracted and the infection could even suppress the aspirin-induced gastropathy.

Preventive and therapeutic strategies for gastrointestinal injury associated with antiplatelet therapy

Antiplatelet therapy is the basic therapy for cardiovascular diseases and is widely used in clinical practice. It can cause damage to the gastrointestinal tract and induce severe events such as gastrointestinal bleeding. It is very important for clinicians to prevent and treat this side effect in patients taking low-dose aspirin and clopidogrel. In this paper we discuss the mechanism, prevention and treament of gastrointestinal injury caused by aspirin and clopidogrel, and introduce the consensus recommendations on reducing the gastrointestinal risk of antiplatelet therapy.

Association of gastric acid and mucus secretion level with low-dose aspirin-induced gastropathy

BACKGROUND

Low-dose aspirin is known to cause upper gastrointestinal complications. The mechanism by which the aspirin disrupts gastric mucosal integrity remains to be clarified. In this study we investigated the temporal association of gastric secretory parameters (acid and mucus) with aspirin-induced gastropathy.

METHODS

In 42 long-term low-dose aspirin-takers and the same number of sex- and age-matched controls, pentagastrin-stimulated gastric juice was collected for 10 min during endoscopic examination. The collected gastric juice was divided and half was submitted to analysis for gastric acid (mEq/10 min) and the other half was analyzed for mucin (mg hexose/10 min) output. The grade of gastric mucosal injury was assessed endoscopically according to the modified Lanza score, and a score of more than 4 was defined as the presence of severe gastropathy.

RESULTS

While gastric acid secretion did not differ significantly between aspirin-takers and controls, gastric mucus secretion, in terms of mucin output, was significantly increased in aspirin-takers compared to controls (4.1 (SD 4.8) vs. 2.3 (1.4) mg hexose/10 min, P < 0.05). Consequently, the acid/mucin ratio was significantly decreased in aspirin-takers compared to controls (1.2 (1.0) vs. 1.7 (1.4), P < 0.05). In the subanalysis of 25 aspirin-takers without severe gastropathy, gastric mucus secretion was increased and the acid/mucus ratio was decreased compared with controls, but there was no such association in the remaining 17 aspirin-takers with severe gastropathy.

CONCLUSION

Overall, gastric mucus secretion is increased in aspirin-takers, suggesting a functional adaptive response to long-term administration of the drug. However, it is possible that the adaptive response is impaired in some aspirin takers, who might be susceptible to severe upper gastrointestinal complication.

Risk factors for peptic ulcer bleeding in terms of Helicobacter pylori, NSAIDs, and antiplatelet agents

OBJECTIVES

The role of the Helicobacter pylori, nonsteroidal anti-inflammatory drugs (NSAIDs), and antiplatelet agents in the risk of peptic ulcer bleeding has not yet been established. This study was performed to identify the risk factors for peptic ulcer bleeding compared with non-bleeding peptic ulcer disease (PUD).

MATERIAL AND METHODS

A total of 475 patients, 265 with bleeding PUD and 210 with non-bleeding PUD were consecutively recruited. H. pylori status was determined by histology, rapid urease test, and culture. Exposure to NSAIDs, aspirin, and antiplatelet agents (clopidogrel and ticlopidine) within 4 weeks was obtained.

RESULTS

Compared with non-bleeding PUD, bleeding PUD had a higher proportion of male gender and current smoking, alcohol drinking, history of aspirin/antiplatelet use, and history of PUD. Whereas the proportion of H. pylori infection and history of H. pylori eradication in bleeding PUD were significantly lower than that in non-bleeding PUD. In multivariate analysis, male gender (OR 1.78, 95% CI 1.10-2.89), drinking alcohol (OR 2.08, 95% CI 1.29-3.14), aspirin/antiplatelet use (OR 2.35, 95% CI 1.45-3.82), and history of PUD (OR 2.46, 95% CI 1.36-4.46) remained independent risk factors for bleeding PUD. When H. pylori status and aspirin/antiplatelet agent use were combined, highest risk of bleeding peptic ulcers was found among H. pylori-negative patients with a history of aspirin/antiplatelet agent use (OR 3.03 95% CI 1.48-6.18) compared with H. pylori-positive patients with no history of aspirin/antiplatelet agent use.

CONCLUSIONS

Patients with H. pylori-negative peptic ulcers who continuously took aspirin or antiplatelet agents had the highest peptic ulcer bleeding risk.

Gastric acid secretion level modulates the association between Helicobacter pylori infection and low-dose aspirin-induced gastropathy

BACKGROUND

The relative contribution of gastric acid secretion and Helicobacter pylori infection to low-dose aspirin-induced gastropathy remains to be clarified. This is partly because the capability of the infection to modify gastric acid secretion complicates the interaction. The aim of this study was to estimate the association of aspirin-induced mucosal injury, as well as H. pylori infection, with gastric acid output.

METHODS

A total of 186 male outpatients, comprising 60 aspirin takers, on 100 mg of enteric-coated aspirin daily and 126 non-aspirin takers were prospectively enrolled in this study. Gastrin-stimulated acid output was estimated by the endoscopic gastrin test. The grade of gastric mucosal injury was assessed endoscopically according to the modified Lanza score. Multiple logistic regression analyses were used to adjust for potential confounders.

RESULTS

The gastric acid secretion level, with an odds ratio (OR) (95% confidence interval [CI]) of 10.5 (3.0-36.9) and aspirin administration, with an OR (95% CI) of 7.4 (3.0-18.3) were independently associated with gastric mucosal injury, and the co-existence of both factors greatly elevated the risk of mucosal injury, with an OR (95% CI) of 77.0 (13.5-440.0). H. pylori infection, itself, did not show any significant effect on the aspirin-induced mucosal injury after adjusting for gastric acid secretion.

CONCLUSIONS

This study has demonstrated that aspirin-induced gastropathy is directly associated with gastric acid secretion. In addition, it also suggested that the gastric acid secretion level modulates the association between H. pylori infection and aspirin-induced gastropathy.

Systematic review: Helicobacter pylori and the risk of upper gastrointestinal bleeding risk in patients taking aspirin

BACKGROUND

Aspirin is widely used to modify the risk of recurrent vascular events. It is, however, associated with increased upper gastrointestinal bleeding risk. The influence of Helicobacter pylori on this risk is uncertain.

AIM

To determine the influence of H. pylori on upper gastrointestinal bleeding risk in patients taking aspirin.

METHODS

MEDLINE and EMBASE databases were searched. All studies providing data regarding H. pylori infection in adults taking aspirin and presenting with upper gastrointestinal bleeding were included.

RESULTS

A total of 13 studies that included 1 case-control, 10 cohort studies and 2 randomized-controlled trials (RCTs) were analysed. The case-control study (n = 245) determined H. pylori to be a significant independent risk factor for upper gastrointestinal bleeding. The cohort studies were heterogeneous, varying in inclusion criteria, doses and duration of aspirin used, mode of H. pylori testing and causative GI pathology considered. Comprising 5465 patients, H. pylori infection was tested for in 163 (0.03%) aspirin users with upper gastrointestinal bleeding. The RCTs yielded no significant results.

CONCLUSIONS

The current data are not sufficient to allow meta-analyses. The widely held belief that H. pylori is a risk factor for upper gastrointestinal bleeding in regular aspirin users is not supported by the very limited evidence available.

Prostaglandin E2 prevents Helicobacter-induced gastric preneoplasia and facilitates persistent infection in a mouse model

BACKGROUND & AIMS

Persistent infection with the human pathogen Helicobacter pylori increases the risk of gastric cancer. In this study, we investigated the role of cyclooxygenase-2 (COX-2) and its main product, prostaglandin E(2) (PGE(2)), in the development of Helicobacter-induced gastritis and gastric cancer precursor lesions.

METHODS

We utilized mouse models of Helicobacter-induced gastric preneoplasia and vaccine-induced protection to study the effects of COX-2 inhibition and PGE(2) treatment on the induction of Helicobacter-specific immune responses and gastric premalignant immunopathology.

RESULTS

COX-2 and PGE(2) are up-regulated upon Helicobacter infection in cultured epithelial cells and in the gastric mucosa of infected mice. Inhibition of COX-2 activity with celecoxib significantly accelerated early preneoplasia; conversely, systemic administration of synthetic PGE(2) prevented development of premalignant pathology and completely reversed preexisting lesions by suppressing interferon-gamma production in the infected stomachs. The protective effect of PGE(2) was accompanied by increased Helicobacter colonization in all models. All in vivo effects were attributed to immunosuppressive effects of PGE(2) on CD4(+) T-helper 1 cells, which fail to migrate, proliferate, and secrete cytokines when exposed to PGE(2) in vitro and in vivo. T-cell inhibition was found to be due to silencing of interleukin-2 gene transcription, and could be overcome by supplementation with recombinant interleukin-2 in vitro and in vivo.

CONCLUSIONS

COX-2-dependent production of PGE(2) has an important immunomodulatory role during Helicobacter infection, preventing excessive local immune responses and the associated immunopathology by inhibiting the effector functions of pathogenic T-helper 1 cells.

Celiac-associated peptic disease at upper endoscopy: how common is it?

OBJECTIVE

Recently, several publications in adults have shown an increased incidence of non-Helicobacter pylori (HP), non-non-steroidal anti-inflammatory drug (NSAID) peptic disease (PD). There are only a few case reports linking celiac disease (CD) to PD. We therefore aimed to review our experience of CD presenting with PD.

MATERIAL AND METHODS

We retrospectively reviewed all the endoscopies performed for children and young adults diagnosed with CD between 1 January, 2004 and 31 October, 2008. The diagnosis of CD was based on accepted guidelines. Patients with a doubtful diagnosis of CD were excluded.

RESULTS

We had 240 patients with the diagnosis of CD. We had 29 (12.0%) patients [15 males (52%), 14 females (48%)] for whom the diagnosis of PD was ascertained. The age range was 1-50 years (mean 16.9 +/- 12.1 years). Twenty-three of the 29 patients (79%) were HP-negative. Duodenal PD was noted in 22 patients (76%) and 16 (73%) were HP-negative. Gastric PD was noted in eight patients (28%) and 7 (87%) were HP-negative. The PD group was significantly older at diagnosis (p < 0.001) compared to the whole CD group.

CONCLUSIONS

PD is not uncommon in the presentation of CD. It is more likely to be found in the second decade of life. CD should be included in the differential diagnosis of patients with non-HP PD and we suggest routine CD serology and small bowel biopsy in patients with unexplained PD.

Short-term/low-dose aspirin-induced duodenal erosions are not dependent on Helicobacter pylori infection, cyclooxygenase expression and prostaglandin E2 levels

OBJECTIVE

The mechanisms of interaction between Helicobacter pylori infection and low-dose aspirin in the induction of duodenal erosions are not fully understood. The aim of this study was to investigate the effects of low-dose aspirin on the induction of duodenal erosions, the expression of cyclooxygenases and prostaglandin (PG)-E(2) levels in healthy subjects according to their H. pylori status.

MATERIAL AND METHODS

Twenty healthy volunteers (H. pylori-negative n=10, H. pylori-positive n=10) received 100 mg aspirin/day for 1 week. During esophagogastroduodenoscopy, duodenal biopsies were taken before and at days 1, 3, and 7 of medication. COX-1 and -2 expressions were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR), and immunohistochemistry; mucosal PGE(2) levels were determined by ELISA. Three months after successful eradication of infection, nine H. pylori-positive subjects repeated the protocol.

RESULTS

Aspirin-induced duodenal erosions occurred independently of whether H. pylori infection was present or not. There was no difference in duodenal COX-1 and COX-2 expression among the groups and expression was not affected by aspirin. Basal duodenal PGE(2) levels were similar among the different groups (H. pylori-negative 4.3+/-4.2, H. pylori-positive 5.2+/-1.3, following H. pylori eradication 5.2+/-1.4 ng/microg protein) and were not affected by low-dose aspirin.

CONCLUSIONS

In healthy subjects, low-dose aspirin-induced duodenal erosions are not influenced by H. pylori status. Low-dose aspirin medication for one week does not affect either cyclooxygenase expression or duodenal PGE(2) levels and therefore is likely to induce duodenal damage mainly through topical toxicity.

Effects of aspirin on the development of Helicobacter pylori-induced gastric inflammation and heterotopic proliferative glands in Mongolian gerbils

BACKGROUND

Helicobacter pylori infection is a major cause of gastritis and gastric carcinoma. Aspirin has anti-inflammatory and antineoplastic activity. The aim of the present study was to determine the effects of aspirin on H. pylori-induced gastritis and the development of heterotopic proliferative glands.

METHODS

H. pylori strain SS1 was inoculated into the stomachs of Mongolian gerbils. Two weeks after inoculation, the animals were fed with the powder diets containing 0 p.p.m. (n = 10), 150 p.p.m. (n = 10), or 500 p.p.m. (n = 10) aspirin. Mongolian gerbils were killed after 36 weeks of infection. Uninfected Mongolian gerbils (n = 10) were used as controls. Histologic changes, epithelial cell proliferation and apoptosis, and prostaglandin E(2) (PGE(2)) levels of gastric tissue were determined.

RESULTS

H. pylori infection induced gastric inflammation. Administration of aspirin did not change H. pylori-induced gastritis, but alleviated H. pylori-induced hyperplasia and the development of heterotopic proliferative glands. Administration of aspirin accelerated H. pylori-associated apoptosis but decreased H. pylori-associated cell proliferation. In addition, the increased gastric PGE(2) levels due to H. pylori infection were suppressed by treatment with aspirin, especially at the dose of 500 p.p.m.

CONCLUSIONS

Aspirin alleviates H. pylori-induced hyperplasia and the development of heterotopic proliferative glands. Moreover, aspirin increases H. pylori-induced apoptosis. We demonstrated the antineoplastic activities of aspirin in H. pylori-related gastric carcinogenesis.

Peptic ulcers and erosions are common in Israeli children undergoing upper endoscopy

BACKGROUND

Peptic ulcers and erosions (PU&E) are thought to be uncommon in children. Patients with early exposure to Helicobacter pylori may be at a higher risk for early onset PU&E. Children in Israel have a high prevalence and early acquisition of Helicobacter pylori (H. pylori) and have easy access to pediatric gastroenterologists and endoscopy. Our aim was to describe the prevalence and characteristics of PU&E in this population referred by Pediatric Gastroenterologists for an upper endoscopy.

METHODS

We conducted a retrospective study over the years January 2003-May 2006. Over these years we had information on 751 diagnostic upper endoscopies. PU&E was regarded as erosive gastritis/duodenitis or ulcer in either the stomach or duodenum. H. pylori status was assessed using rapid urease test and gastric biopsies.

RESULTS

PU&E was detected in 169 (22.5%) patients (ulcers 51 (6.8%), erosions 118 (15.7%)). One hundred twenty-four had gastric PU&E and 58 had duodenal PU&E. H. pylori was positive in 112 (66.3%). H. pylori-associated PU&E becomes common after age 10 years, with gastric PU&E presenting much earlier than duodenal disease. Most of the H. pylori-negative PU&E were idiopathic and improved symptomatically on PPI treatment. Interestingly, 43% of patients with PU&E in our cohort were either immigrants from the former Soviet Union or of Israeli Arab origin.

CONCLUSIONS

PU&E appears to be common in this selected population with a relatively high incidence of gastric PU&E. H. pylori associated PU&E becomes common after age 10 years with gastric PU&E presenting much earlier than duodenal disease. Non H. pylori PU&E in children comprises approximately a third of all PU&E, are mostly idiopathic and appear earlier than H. pylori associated PU&E.

Semi-micro column high-performance liquid chromatography with UV detection for quantification of aspirin and salicylic acid and its application to patients' sera administered with low-dose enteric-coated aspirin

A simultaneous determination of aspirin (ASA) and its metabolite, salicylic acid (SA), in human serum by a semi-micro column HPLC-UV was developed. A relatively small size of serum sample (100 microL) containing ASA and SA was cleaned up by a simple solid phase extraction. A good separation of ASA and SA could be achieved within 25 min using a semi-micro ODS column with an eluent of MeOH/0.7 mm phosphoric acid solution (pH 2.5) = 50:50 (v/v). The calibration curves for ASA and SA showed good linearity (r = 0.999) with the detection limits 114 and 38 ng/mL at a signal-to-noise ratio of 3, respectively. ASA and SA in patients' sera administered with low-dose enteric-coated aspirin were determined, and the concentration ranges obtained for ASA and SA were 1.2-2.2 and 0.5-57.3 microg/mL, respectively.

Improving the gastrointestinal tolerability of aspirin in older people

Interventions to reduce mortality and disability in older people are vital. Aspirin is cheap and effective and known to prevent cardiovascular and cerebrovascular disease, many cancers, and Alzheimer dementia. The widespread use of aspirin in older people is limited by its gastrointestinal side effects. Understanding age-related changes in gastrointestinal physiology that could put older people at risk of the side effects of aspirin may direct strategies to improve tolerance and hence lead to greater numbers of older people being able to take this effective intervention.

[Epidemiology of digestive complications associated with use of low-dose aspirin]

Low-dose aspirin (< 330 mg/d) is recommended for the prevention of myocardial infarction or ischemic stroke. Six to 12% of the general population is exposed to low-dose aspirin. The most frequently studied digestive complications are bleeding peptic ulcers, whose risk is increased twofold by low-dose aspirin treatment, and non-complicated peptic ulcers. History of bleeding or non-complicated peptic ulcer, alcohol intake, concomitant treatment with NSAID or calcic inhibitors are demonstrated risk factors of bleeding ulcer associated with low-dose aspirin. The role of enteric coating, of low-dose aspirin dose, of delay since low-dose aspirin treatment onset, and of Helicobacter pylori infection, remains controversial. Antisecretory drugs (H2 inhibitors, proton pump inhibitors), and nitroglycerin are associated with a decreased risk of bleeding ulcer. The protective effect of COX-2 inhibitors on the risk of bleeding ulcer is suppressed by concomitant treatment with low-dose aspirin. The risk of no- complicated peptic ulcer was increased by low-dose aspirin intake by a factor 2.9 in one study. Low-dose aspirin dose, infection by Helicobacter pylori, NSAID intake, and absence of enteric coating, are possible risk factors for non-complicated peptic ulcer. No association was retrieved with alcohol intake and peptic ulcer history.

Helicobacter pylori infection and the prevention of peptic ulcer with proton pump inhibitors in elderly subjects taking low-dose aspirin

INTRODUCTION

The role of Helicobacter pylori infection on the risk of low-dose aspirin-related gastroduodenal damage and on the efficacy of the prevention therapy in elderly chronic users of low-dose aspirin is still controversial.

AIM

To evaluate in symptomatic elderly chronic users of low-dose aspirin: (1) the association between H. pylori infection and the prevalence of upper gastrointestinal lesions; and (2) the effect of H. pylori infection on the efficacy of proton pump inhibitors in the prevention of aspirin-related gastroduodenal lesions.

PATIENTS AND METHODS

Two hundred and forty-five symptomatic elderly who were taking aspirin 75-300 mg daily, at least during the last 3 months, were evaluated by endoscopy. A structured interview was carried out to evaluate gastrointestinal symptoms and the use of proton pump inhibitors. H. pylori infection was diagnosed according to histology and the rapid urease test on gastric biopsies.

RESULTS

One hundred and twelve patients were H. pylori-positive and 133 patients were H. pylori-negative. A significantly higher prevalence of peptic ulcers was observed in H. pylori-positive than in H. pylori-negative subjects (36.6% versus 15.8%, P = 0.0002). The use of proton pump inhibitors was associated with a significant decreased risk of peptic ulcer both in H. pylori-positive (absolute risk reduction, ARR = -36.2, 95% confidence interval: -51.2 to -21.3, P < 0.001) and H. pylori-negative patients (ARR = -12.6, 95% confidence interval: -23.9 to -1.2, P = 0.03). However, the number of patients who needed to be treated in order to gain a reduction of one peptic ulcer (number needed to treat, NnT) was lower in H. pylori-positive than in H. pylori-negative patients (NnT = 3 versus 8).

CONCLUSIONS

In symptomatic elderly chronic users of low-dose aspirin, H. pylori infection may influence the prevalence of peptic ulcers and the cost-effectiveness of the proton pump inhibitor prevention therapy.

[Prevention of gastroduodenal complications in patients taking low-dose aspirin]

Use of low-dose aspirin is associated with an increased risk of gastroduodenal ulcers and upper gastrointestinal bleeding. The risk is increased by the old age and by cardiovascular and cerebrovascular diseases of the patients receiving low-dose aspirin. Combination with nonsteroidal anti-inflammatory drugs, corticosteroids or anticoagulant increases the risk of complications and should be avoided. Proton-pump inhibitor and eradication of Helicobacter pylori are not efficient in primary prevention of ulcer complications related to low-dose aspirin use. Patients at high risk of gastroduodenal complications due to age, morbidity or concomitant use of gastrotoxic therapy should be given prophylactic treatment. Assessment of what constitutes the most effective therapy (misoprostol, proton-pump inhibitor) should be defined in controlled trials. Among patients with Helicobacter pylori infection and a history of upper gastrointestinal bleeding who are taking low-dose aspirin, the eradication of Helicobacter pylori is equivalent to treatment with proton-pump inhibitor in preventing recurrent bleeding. Long term treatment with proton-pump inhibitor in addition to the eradication of Helicobacter pylori should be considered in patients who had ulcer complications related to the use of low-dose aspirin.

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Review article: the ageing bowel and intolerance to aspirin

Aspirin has a role in the prevention of cardiovascular and cerebrovascular disease, Alzheimer's dementia and several cancers. Encouraging all 50 year olds to take low-dose aspirin doubles their chances of living a healthy life into their nineties. The widespread use of aspirin, however, is limited as many older subjects are currently unable to take aspirin because of gastrointestinal side-effects. This review explores why gastrointestinal events occur with aspirin use and how a net benefit from prophylactic aspirin might be achieved in older subjects. It is suggested that, by understanding the age-related changes in upper gastrointestinal physiology and the mechanisms by which aspirin leads to the risk reductions associated with its use, it may be possible to direct interventions to improve tolerability in older subjects. This would allow greater numbers of older subjects to gain the benefits associated with aspirin use.

Anti-inflammatory effect of two isoforms of COX in H. pylori-induced gastritis in mice: possible involvement of PGE2

Neutrophil infiltration mediated by TNF-alpha is associated with various types of gastric injury, whereas PGs play a crucial role in gastric defense. We examined roles of two isoforms of cyclooxygenase (COX) and PGE2 in Helicobacter pylori-induced gastritis in mice. Mice infected with H. pylori were given selective COX-1 inhibitor SC-560 (10 mg/kg), selective COX-2 inhibitor NS-398 (10 mg/kg), or nonselective COX inhibitor indomethacin (2 mg/kg) with or without 16,16-dimethyl PGE2 for 1 wk. H. pylori infection increased levels of mRNA for COX-1 and -2 in gastric tissue by 1.2-fold and 3.3-fold, respectively, accompanied by a significant increase in PGE2 production by gastric tissue. H. pylori infection significantly elevated MPO activity, a marker of neutrophil infiltration, and epithelial cell apoptosis in the stomach. SC-560 augmented MPO activity and epithelial cell apoptosis with associated reduction in PGE2 production, whereas NS-398 had the same effects without affecting PGE2 production. Inhibition of both COX-1 and -2 by indomethacin or concurrent treatment with SC-560 and NS-398 resulted in a stronger increase in MPO activity and apoptosis than inhibition of either COX-1 or -2 alone. H. pylori infection elevated TNF-alpha mRNA expression in the stomach, which was further increased by indomethacin. Effects of COX inhibitors on neutrophil infiltration, apoptosis, and TNF-alpha expression in H. pylori-infected mice were abolished by exogenous 16,16-dimethyl PGE2. In conclusion, PGE2 derived from either COX-1 or -2 is involved in regulation of gastric mucosal inflammation and contributes to maintenance of mucosal integrity during H. pylori infection via inhibition of TNF-alpha expression.

Effect of Helicobacter pylori infection and low-dose aspirin use on iron stores in the elderly

BACKGROUND AND AIMS

Helicobacter pylori infection has been associated with lower ferritin levels in some adult populations, but subsets of potentially higher risk subjects, such as the elderly have not been examined. The aim of the present study was to determine the impact of H. pylori infection and low-dose aspirin use on iron stores in a well elderly population.

METHODS

Consecutive subjects aged 65 years or older attending day care facilities were studied. Each subject was assisted in completing a medical questionnaire. Serum ferritin, hemoglobin, mean corpuscular volumes (MCV) and IgG antibodies (ELISA) against H. pylori were measured.

RESULTS

In 220 subjects (age 75 +/- 8 years), 42% were H. pylori seropositive (male 41%, female 44%). The median (IQR) ferritin level (ug/L) was higher in men 149 (89-280) than women 94 (54-161), p < 0.002. The ferritin levels were not different in H. pylori positive males 151 (105-283) compared with H. pylori negative males 145 (72-249), or H. pylori positive females 93 (60-142) compared with H. pylori negative females 97 (45-149). This relationship was not altered when controlled for non-steroidal anti-inflammatory agents (NSAID) use (9% of subjects), alcohol or dietary iron intake. Low-dose aspirin use was common (28%), but did not have an independent impact on iron stores: male users 181 (95-248), non-users 145 (86-284); female users 92 (43-162), non-users 95 (62-163). However, in female aspirin users, H. pylori infection was associated with significantly lower ferritin levels: 65 (43-112) compared with uninfected subjects 103 (41-180), p < 0.04.

CONCLUSIONS

In this well elderly population, the combination of H. pylori infection and low-dose aspirin use was associated with significantly lower serum ferritin concentrations in females. This difference supports the observation that H. pylori, even in asymptomatic subjects, may be a stressor of iron stores.

Effect of cyclooxygenase-2 inhibition on human Helicobacter pylori gastritis: mechanisms underlying gastrointestinal safety and implications for cancer chemoprevention

Cyclooxygenase (COX)-2 expression and prostaglandin production is increased by Helicobacter pylori infection. Non-selective COX inhibitors reduce prostaglandins and mucosal proliferation in infected mucosa and may reduce gastric cancer risk, but ulceration precludes their use. COX-2 inhibitors cause fewer ulcers and may be chemopreventive. Physiological studies of COX-2 inhibitors in humans with H. pylori infection have not been performed.

AIM

To study the impact of COX-2 specific inhibition on gastric prostaglandin levels, H. pylori gastritis and proliferation.

METHODS

Twenty infected (eight males, 12 females; age 38 +/- 1.8) and six uninfected (four males, two females; age 36 +/- 3.5) healthy volunteers received rofecoxib 25 mg daily for 14 days. Endoscopic biopsies were evaluated for prostaglandin E2 (PGE2) content, gastritis and proliferation.

RESULTS

Before drug therapy, compared to uninfected, H. pylori-infected subjects had significantly higher: (a) gastric mucosal PGE2 (pg/mg tissue) in the gastric body and antrum, (b) H. pylori score in body and antrum and (c) mid-gland proliferation index in antrum and body. The COX-2 inhibitor did not significantly affect PGE2 levels, gastritis scores or proliferation indices in the body or antrum in the H. pylori-positive or -negative subjects.

CONCLUSION

The predominant source of increased gastric PGE2 in H. pylori infection appears to be COX-1-derived. In non-ulcerated H. pylori gastritis, COX-2 inhibition does not affect cellular proliferation. Rofecoxib's lack of effect on gastric prostaglandin levels and proliferation in H. pylori-infected mucosa may explain the absence of an increased ulcer risk among COX-2 inhibitor users with H. pylori infection. The lack of significant effect on intermediate biomarkers raises uncertainty regarding the potential of specific COX-2 inhibitors for chemoprevention of gastric cancer.

Pathogenesis and therapy of gastric and duodenal ulcer disease

Despite the decreasing frequency of Helicobacter pylori-induced peptic ulcers, peptic ulcer disease remains a major clinical problem partly because nonsteroidal anti-inflammatory drug ulcers have increased in frequency. The reduction in nonsteroidal anti-inflammatory drug ulcers by use of selective cyclooxygenase-2 inhibitors will not eliminate the problem because of increased use of aspirin for cardiovascular prophylaxis. This article reviews current concepts of peptic ulcer pathogenesis and therapy according to ulcer etiology; discusses potential interactions between etiologies; and considers the therapy for H pylori infection including the effects of antimicrobial resistance, and the role of bismuth quadruple therapy or furazolidone salvage therapy.

Nonsteroidal antiinflammatory drugs and the stomach

We review papers on nonsteroidal antiinflammatory drugs (NSAID) and the stomach published in the 12 months ending April 2002. During this period, some further developments occurred in the ongoing search for safer antiinflammatory drugs. The highly selective COX-2 inhibitors (COX-2i) have again exhibited some toxicity in animal models of repair, but continue to seem a safer alternative than nonselective inhibitors from the standpoint of the production of human ulcers. Some data on the gastrointestinal safety of valdecoxib and parecoxib are available, while co-therapies with acid suppressants to reduce the risk of conventional NSAID also remain an option (a study comparing lansoprazole with misoprostol is now published). Whether co-prescribing a proton pump inhibitor with a COX-2i in patients at higher risk is effective or justified awaits the results of yet to be completed studies. The nitric oxide (NO)-donating NSAID and NO-donating aspirin show some distinct promise in animal studies and early-phase clinical trials.

Helicobacter pylori increases the risk of upper gastrointestinal bleeding in patients taking low-dose aspirin

AIM

To evaluate the role of Helicobacter pylori infection and other clinical factors in the risk of upper gastrointestinal bleeding in patients taking low-dose aspirin.

SUBJECTS AND METHODS

A case-control study was carried out of consecutive current users of low-dose aspirin admitted because of upper gastrointestinal bleeding. Within a cohort of 695 patients with upper gastrointestinal bleeding, 98 patients had taken low-dose aspirin and no other non-steroidal anti-inflammatory drug. Controls were 147 low-dose aspirin users without upper gastrointestinal bleeding of similar age, sex and extent of aspirin use as cases. H. pylori infection was determined by CagA/VacA serology and 13C-urea breath test in all cases and controls. Adjusted odds ratios (OR) are provided.

RESULTS

H. pylori infection was identified as an independent risk factor of upper gastrointestinal bleeding in this population (OR, 4.7; 95% confidence interval (95% CI), 2.0-10.9), but the presence of CagA-positive serology was not. Other risk factors identified were a previous ulcer history (OR, 15.2; 95% CI, 3.8-60.1), alcohol use (OR, 4.2; 95% CI, 1.7-10.4) and use of calcium channel blockers (OR, 2.54; 95% CI, 1.25-5.14). Antisecretory therapy (OR, 0.1; 95% CI, 0.02-0.3) and nitrovasodilators (OR, 0.2; 95% CI, 0.1-0.6) decreased the risk of bleeding.

CONCLUSIONS

H. pylori infection is a risk factor for upper gastrointestinal bleeding in low-dose aspirin users, which might have therapeutic implications in high-risk patients.

Mucosal defense and repair. Role of prostaglandins in the stomach and duodenum

When considering the diseases of the stomach and duodenum, peptic ulcer disease has been the one of greatest clinical impact. Although there are several components that contribute mechanistically to ulcer disease, it is recognized that gastroduodenal mucosal prostaglandins play a central pathogenic role, especially in ulcers related to the use of NSAIDs. As a result of understanding the mechanisms of NSAID-induced ulceration, the crucial function that gastroduodenal mucosal prostaglandins have in mucosal defense and repair is appreciated. It now is held widely that mucosal prostaglandin deficiency increases susceptibility to ulcer formation and that exogenous administration of supplemental prostaglandins reduces ulcer risk. This article reviews the role that mucosal prostaglandins play in defense of the gastric and duodenal mucosa against injury and ulceration.

Nonsteroidal anti-inflammatory drug gastrointestinal toxicity

Toxic effects in the upper gastrointestinal tract, primarily complicated gastric and intestinal ulcers, are the most common undesirable effects of the nonsteroidal anti-inflammatory drugs. During the last several years, there have been several advances, both in the laboratory and clinically, toward reducing nonsteroidal anti-inflammatory drugs' gastrointestinal toxicity. Some of these important developments are the delineation of mechanisms of nonsteroidal anti-inflammatory drug-induced gastrointestinal toxicity, identification of groups at highest risk for development of nonsteroidal anti-inflammatory drug-induced gastrointestinal complications, recognition of co-therapies that could reduce nonsteroidal anti-inflammatory drug toxicity, and, most recently, development of classes of nonsteroidal anti-inflammatory drugs with improved gastrointestinal safety profiles. Many of these advances have occurred during the last year. This review focuses on several of the important recent observations that have improved understanding and safety of nonsteroidal anti-inflammatory drugs in the gastrointestinal tract.