Does Helicobacter pylori protect against eosinophilic esophagitis in children?

Meta-Analysis: Inverse Association Between Helicobacter pylori Infection and Eosinophilic Oesophagitis

BACKGROUND

Exposure to Helicobacter pylori (H. pylori) has been associated with a decreased risk of eosinophilic oesophagitis (EoE).

AIM

The aim of this study is to determine the association between H. pylori infection and EoE in this updated meta-analysis.

METHODS

We searched MEDLINE, Scopus and ISI Web of Science, through to November 2024. We included studies reporting the status of H. pylori infection in patients with and without EoE or oesophageal eosinophilia (EE). We used a random-effects model to pool estimates.

RESULTS

We analysed 19 studies including 1.704.821 subjects. H. pylori infection was associated with a 46% lower risk of EoE/EE (OR: 0.54, 95% CI 0.43 to 0.67). Comparable findings were observed when subgrouping studies by location or design. There was a nonsignificant decrease in odds for EoE in paediatric patients exposed to H. pylori (OR 0.57, 95% CI 0.26 to 1.24), and in studies using serology to diagnose H. pylori (OR: 0.41, 95% CI 0.16 to 1.04). We found lower odds of EoE compared with the overall findings in studies that diagnosed H. pylori only by gastric biopsy (OR 0.43, 95% CI 0.25 to 0.74) and in those published after 2019 (OR 0.44, 95% CI 0.28 to 0.68).

CONCLUSIONS

Exposure to H. pylori was significantly associated with decreased odds of EoE/EE. As a stronger protective effect was found in more recent studies, the epidemiology of this association may evolve and deserve to be further monitored.

The Association Between Helicobacter pylori Infection and Eosinophilic Esophagitis: Systematic Review and Meta-Analysis

BACKGROUND

Exposure to Helicobacter pylori (H. pylori) has been associated with reduced odds of eosinophilic esophagitis (EoE).

AIMS

To conduct a systematic review and meta-analysis of epidemiological studies in order to quantify the association between H. pylori infection and EoE, and to assess the certainty of the evidence linking both conditions.

METHODS

A comprehensive literature search was conducted in MEDLINE/PUBMED, EMBASE, and SCOPUS databases (up to September 2024) to identify observational epidemiological studies that assessed the association between objectively measured H. pylori infection and EoE. The risk of study bias was assessed structurally using the ROBINS-E tool. Data were pooled using a random-effects meta-analysis. The certainty of the evidence was assessed using the GRADE approach.

RESULTS

Sixteen studies comprising 30,650 patients and 291,908 controls were included. Exposure to H. pylori was associated with a significant reduction in the odds of EoE (pooled odds ratio [OR] 0.56; 95% CI, 0.46-0.70; I2 50%) [low-certainty evidence]. The protective effect of H. pylori was stronger in case-control studies (OR 0.49; 95% CI, 0.35-0.69) than in cohort studies (OR 0.76; 95% CI, 0.58-0.98) and was statistically significant in retrospective studies (OR 0.57; 95% CI, 0.45-0.72) and studies with high or very high risk of bias (OR 0.52; 95% CI, 0.42-0.64), but not in prospective studies (OR 0.56; 95% CI, 0.27-1.18) or those with moderate to low risk of bias (OR, 0.91; 95% CI, 0.69-1.21).

CONCLUSIONS

The association between H. pylori and EoE is mainly supported by retrospective studies with a high risk of bias. Further well-designed studies are needed.

TRIAL REGISTRATION

PROSPERO number: CRD42024586653.

Diagnosis and management of eosinophilic esophagitis in children: An update from the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN)

INTRODUCTION

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus characterized by symptoms of esophageal dysfunction and histologically by predominantly eosinophilic infiltration of the squamous epithelium. European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) published a guideline in 2014; however, the rapid evolution of knowledge about pathophysiology, diagnostic criteria, and therapeutic options have made an update necessary.

METHODS

A consensus group of pediatric gastroenterologists from the ESPGHAN Working Group on Eosinophilic Gastrointestinal Diseases (ESPGHAN EGID WG) reviewed the recent literature and proposed statements and recommendations on 28 relevant questions about EoE. A comprehensive electronic literature search was performed in MEDLINE, EMBASE, and Cochrane databases from 2014 to 2022. The Grading of Recommendations Assessment, Development and Evaluation system was used to assess the quality of evidence and formulate recommendations.

RESULTS

A total of 52 statements based on the available evidence and 44 consensus-based recommendations are available. A revision of the diagnostic protocol, options for initial drug treatment, and the new concept of simplified empiric elimination diets are now available. Biologics are becoming a part of the potential armamentarium for refractory EoE, and systemic steroids may be considered as the initial treatment for esophageal strictures before esophageal dilation. The importance and assessment of quality of life and a planned transition to adult medical care are new areas addressed in this guideline.

CONCLUSION

Research in recent years has led to a better understanding of childhood EoE. This guideline incorporates the new findings and provides a practical guide for clinicians treating children diagnosed with EoE.

Causality of Helicobacter pylori infection on eosinophilic esophagitis and potential pathogenesis: a Mendelian randomization study

Background

Observational studies have indicated a possible connection between Helicobacter pylori (H. pylori) infection and eosinophilic esophagitis (EoE), but their causal relationship has yet to be established. To investigate the causal associations between H. pylori infection and EoE, we performed a Mendelian randomization (MR) analysis.

Methods

Firstly, we conducted both univariable and multivariable Mendelian randomization (MR) analyses. Furthermore, a two-step MR was carried out to ascertain the potential underlying pathways of these associations, particularly the involvement of inflammatory cytokines. We employed the inverse-variance weighted (IVW) method as the main analysis in our MR study. To enhance the credibility of the results, we also conducted several sensitivity analyses.

Results

Our study demonstrated a noteworthy correlation between genetically predicted anti-H. pylori IgG antibody levels and a reduced risk of EoE (OR=0.325, 95% CI=0.165-0.643, P value=0.004, adj p value=0.009). No significant causal associations were detected between other H. pylori antibodies and EoE in our study. When it comes to multivariable MR analysis controlling for education attainment, household income, and deprivation individually, the independent causal impact of anti-H. pylori IgG on EoE persisted. Surprisingly, the two-step MR analysis indicated that inflammatory factors (IL-4, IL-5, IL-13, IL-17, and IFN-γ) did not appear to mediate the protective effect of H. pylori infection against EoE.

Conclusion

Findings suggested that among the range of H. pylori-related antibodies, anti-H. pylori IgG antibody is the sole causal factor associated with protection against EoE. Certain inflammatory factors may not be involved in mediating this association. These findings make a significant contribution to advancing our understanding of the pathogenesis of EoE and its evolving etiology.

Helicobacter pylori infection is associated with decreased odds for eosinophilic esophagitis in Mexican patients

BACKGROUND

The incidence of eosinophilic esophagitis (EoE) is increasing in some regions of the world. Retrospective studies have found an inverse association with Helicobacter pylori infection (H. pylori). A recent prospective study has questioned this relationship. We aimed to evaluate this relationship in Mexican patients.

PATIENTS AND METHODS

We evaluated adult patients without prior eradication of H. pylori. Cases were defined by the presence of esophageal symptoms and >15 eosinophils/high power field (HPF) in the esophageal biopsy. Controls were defined by the presence of <15 eosinophils/HPF in esophageal biopsy. H. pylori infection was defined by histology. Patients were matched by age and gender assigning four controls per case.

RESULTS

We included 190 patients: 38 cases and 152 controls. Cases had higher frequency of atopy, dysphagia, food impaction, peripheral eosinophilia, and endoscopic EoE abnormalities. The overall prevalence of H. pylori was 63.6%. Cases had significantly lower prevalence of H. pylori than controls (36.8% vs. 70.4%, OR 0.21 95% CI 0.08-0.69, p = 0.001). Atopic patients had lower prevalence of H. pylori than non-atopic: 13.1% vs. 50.5% (OR 0.20, 95% CI 0.06-0.69, p < 0.001), particularly allergic rhinitis and food allergy.

CONCLUSIONS

We observed an inverse relationship between H. pylori and EoE as well as atopy. Studies in experimental models of EoE that clarify the role of H. pylori in this interaction are required, as well as robust studies that include other factors (socioeconomic, cultural, microbiota, etc.) in order to clarify this relationship.

Helicobacter pylori in children: think before you kill the bug!

Since the discovery of Helicobacter pylori (H. pylori) as the causative organism for gastric and duodenal ulcers four decades ago and subsequent recognition as class 1 gastric carcinogen, countless numbers of studies have been conducted and papers published, on the efficacy of various management strategies to eradicate the infection. In adults, a global consensus by the experts in the field concluded that H. pylori gastritis is an infectious disease and requires treatment irrespective of the presence or absence of symptoms due to the potential for serious complication like peptic ulcer disease and gastric neoplasia. However, although more than half the world's population harbors H. pylori, these serious complications occur only in a small minority of the infected population, even less so in childhood. More importantly, there is accumulating evidence for beneficial role of H. pylori against many chronic health conditions, from several epidemiological and laboratory studies. No doubt, eradication therapy is indicated in children with H. pylori-related peptic ulcer disease. Even though the pediatric guidelines from various learned societies recommend against a "test and treat" strategy, this is not always adhered to. With the accumulating evidence of the possible beneficial role of H. pylori, it is time to pause and think, are we causing more harm than good by eradicating H. pylori in every child who has this bug?

Antibiotics in the pathogenesis of diabetes and inflammatory diseases of the gastrointestinal tract

Antibiotic use is increasing worldwide. However, the use of antibiotics is clearly associated with changes in gut microbiome composition and function, and perturbations have been identified as potential environmental risk factors for chronic inflammatory disorders of the gastrointestinal tract. In this Review, we examine the association between the use of antibiotics and the onset and development of both type 1 and type 2 diabetes, inflammatory bowel disease, including ulcerative colitis and Crohn's disease, as well as coeliac disease and eosinophilic oesophagitis. We discuss the key findings of epidemiological studies, provide mechanistic insights into the pathways by which the gut microbiota might contribute to these diseases, and assess clinical trials investigating the effects of antibiotics. Such studies indicate that antibiotic exposures, varying in type, timing and dosage, could explain differences in disease risk. There seems to be a critical window in early life in which perturbation of the microbiome has a substantial effect on disease development. Identifying the antibiotic-perturbed gut microbiota as a factor that contributes to the pathophysiology of these inflammatory disorders might stimulate new approaches to prevention, diagnosis and treatment.

Low Prevalence of Extraesophageal Gastrointestinal Pathology in Patients with Eosinophilic Esophagitis

BACKGROUND

Limited data are available to support current guidelines recommendations on obtaining gastric and duodenal biopsies of patients with clinical and histologic manifestations consistent with eosinophilic esophagitis (EoE) to rule out eosinophilic gastritis (EG) or duodenitis (EoD). Our study examined the prevalence of concomitant extraesophageal, gastrointestinal pathology to better characterize the diagnostic yield of additional biopsies.

METHODS

This was a single-center, retrospective study which utilized ICD 9 codes (530.13) and search queries of pathology reports ("Eosinophilic esophagitis," "EoE") to identify EoE patients. Patient endoscopy reports, pathology reports, and office notes were manually reviewed to characterize cases.

RESULTS

The electronic health record search yielded 1,688 EoE adults. In those who had extra-esophageal biopsies obtained, EG was identified in 34 (3.4%), H. pylori in 45 (4.6%), EoD in 27 (3.3%), and histology consistent with celiac disease in 20 (2.5%). Endoscopic abnormalities were found in the stomach of 92% of patients with EoE and EG and in the duodenum of 50% of patients with EoE and EoD. Symptoms of dyspepsia and/or abdominal pain occurred in a significantly greater proportion of patients with extraesophageal disease (64% vs. 19% in EoE group, p < 0.001). Overall, extraesophageal pathology would have been missed in 1.4% of patients lacking either symptoms or endoscopic signs suggestive of extraesophageal disease.

CONCLUSIONS

The yield of gastric and duodenal biopsies in adults with EoE is low, with 6.5% of patients demonstrating histologic features of celiac disease, Helicobacter pylori, EG, and/or EoD. Biopsies of extraesophageal, gastrointestinal sites in patients with suspected or previously diagnosed EoE should consider symptom and endoscopy manifestations as well as the potential impact of histopathologic findings on clinical management.

MALT lymphoma and eosinophilic oesophagitis: incidental finding- review of possible factors influencing the aetiopathogenesis of eosinophilic oesophagitis

An 11-year-old boy with a history of atopy and allergic rhinitis under treatment with sublingual immunotherapy was referred following several episodes of food impaction. Diagnosis of eosinophilic oesophagitis, chronic gastritis and gastric mucosa-associated lymphoid tissue (MALT) lymphoma associated to Helicobacter pylori were confirmed. Results of the extension study were negative and the lymphoma was resolved with eradicating treatment for H. pylori No improvement was observed in the oesophagitis after the withdrawal of immunotherapy and treatment with high proton pump inhibitor doses or following the omission of several foods to which subclinical sensitisation was confirmed. Oesophagitis was finally resolved by removing cow's milk protein. After 10 years, neither eosinophilic oesophagitis nor MALT lymphoma was observed.Gastric MALT lymphoma associated to H. pylori is a rare disorder in children. Although coexisting H. pylori infection is common in patients with eosinophilic oesophagitis, the association of gastric MALT lymphoma with eosinophilic oesophagitis has not been reported before.

Changing prevalence of Helicobacter pylori infection in children and adolescents

Helicobacter pylori infection has declined over recent decades. However, its prevalence remains high, and nearly 50% of the global population has been infected. In Korea, seroprevalence has steadily decreased in adults, but the status of H. pylori infection in children is unknown. The current status or trend of H. pylori infection in children is important because it can help estimate H. pylori-related diseases including gastric cancer in later life. In this review, the authors discuss the change in H. pylori infection rate among children and adolescents based on literature reviews and our research.

Epidemiology and risk factors for eosinophilic esophagitis: lessons for clinicians

INTRODUCTION

The rapid expansion in the epidemiology of eosinophilic esophagitis (EoE) is being documented, along with cumulative research assessing environmental exposures associated with EoE and susceptibility due to genetic variants.

AREAS COVERED

Incidence rates for EoE of 5-10 new cases per 100,000 inhabitants annually have shown an increase in recent reports of up to 20 in some countries; the highest prevalence being reported for Europe and North America, where EoE now affects more than 1 out of 1,000 people. EoE has been shown to be associated with several disorders, Th2-mediated atopies being the most common. Patients with EoE exhibit increased frequency of asthma, allergic rhinitis and eczema, and EoE has been considered as a late component of the atopic march. Risk variants in TSLP, CAPN14 and LRCC32 genes, among others, have all been related to EoE, and interact with prenatal and early life exposure potentially modifying abundance and composition of gut microbiome. Dysregulated interactions between bacteria and mucosal immunity emerge as leading causes of EoE.

EXPERT OPINION

The expanding epidemiology of EoE, the resources needed and subsequent increasing healthcare costs require additional effort to optimize cost-effective management and unveil mechanisms that enhance the development of future preventive strategies.

Reconsidering the "protective" hypothesis of Helicobacter pylori infection in eosinophilic esophagitis

Since its discovery, Helicobacter pylori (H. pylori) has attracted attention in the biomedical world with its numerous pathophysiologic implications, both gastrointestinal and systemic. Beyond its well-established carcinogenic properties, emerging evidence also supports "harmful" proinflammatory and neurodegenerative roles of H. pylori. On the other hand, H. pylori infection has been proposed to be "protective" against several diseases, such as asthma and gastroesophageal reflux disease. Eosinophilic esophagitis (EoE) is a relatively new, allergen/immune-mediated disease, which has also been linked to these considerations. Main arguments are a postulated shift of immune responses by H. pylori from T helper 2 (T_H 2) to T_H 1 polarization, as well as a potential decline of the H. pylori burden with the dramatic parallel rise of ΕοΕ: a series of observational studies reported an inverse association. In this review, we counter these arguments by providing further epidemiological data, which point out that this generalization might be rather incomplete. We also discuss the limitations of the existing studies evaluating a possible association. Furthermore, we provide current evidence on common pathogenetic components, which share both entities. In summary, the claim that H. pylori is protective against EoE is rather incomplete, and further mechanistic studies are necessary to elucidate a possible association.

Early Life Risk Factors in Pediatric EoE: Could We Prevent This Modern Disease?

Eosinophilic esophagitis (EoE) is a chronic antigen-mediated inflammatory disease that affects the esophagus. In the last 20 years, a large number of epidemiological studies showed a significant increase in the incidence and prevalence of EoE, especially in developed countries. This phenomenon might correlate to the overall increase in pediatric allergic diseases or might be a result of improved medical awareness and knowledge through modern diagnostic instruments. Since 1993, when EoE was first recognized as a distinct clinical entity, several signs of progress in the pathophysiology of EoE were achieved. However, a few studies reported data on early risk factors for pediatric EoE and how these factors may interfere with genes. Currently, the most defined risk factors for EoE are male sex, Caucasian race, and atopic comorbidities. Other putative risk factors may include alterations in epithelial barrier function and fibrous remodeling, esophageal dysbiosis, variation in the nature and timing of oral antigen exposure, and early prescription of proton pump inhibitors and antibiotics. Notably, the timing and nature of food antigen exposure may be fundamental in inducing or reversing immune tolerance, but no studies are reported. This review summarized the current evidence on the risk factors that might contribute to the increasing development of EoE, focusing on the possible preventive role of early interventions.

Association Between Helicobacter pylori Exposure and Decreased Odds of Eosinophilic Esophagitis-A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Previous or current infection with Helicobacter pylori (exposure) has been reported to protect against eosinophilic esophagitis (EoE), perhaps owing to H pylori-induced immunomodulation. However, findings vary. We performed a systematic review and meta-analysis of comparative studies to define the association between H pylori exposure and EoE more clearly.

METHODS

We searched 4 large databases to identify comparative clinical studies that included sufficient detail to determine the odds or risk of EoE (primary outcome) or esophageal eosinophilia (secondary outcome) among individuals exposed to H pylori (exposed) vs individuals who were tested and found to be unexposed. Estimates were pooled using a random-effects model. Meta-regression and sensitivity analyses were planned a priori. Studies were evaluated for quality, risk of bias, publication bias, and heterogeneity.

RESULTS

We analyzed 11 observational studies comprising data on 377,795 individuals worldwide. H pylori exposure vs nonexposure was associated with a 37% reduction in odds of EoE (odds ratio, 0.63; 95% CI, 0.51-0.78) and a 38% reduction in odds of esophageal eosinophilia (odds ratio, 0.62; 95% CI, 0.52-0.76). Fewer prospective studies found a significant association between H pylori exposure and EoE (P = .06) than retrospective studies. Effect estimates were not affected by study location, whether the studies were performed in pediatric or adult populations, time period (before vs after 2007), or prevalence of H pylori in the study population.

CONCLUSIONS

In a comprehensive meta-analysis, we found evidence for a significant association between H pylori exposure and reduced odds of EoE. Studies are needed to determine the mechanisms of this association.

Allergic Comorbidity in Eosinophilic Esophagitis: Mechanistic Relevance and Clinical Implications

Allergic eosinophilic esophagitis (EoE) is a chronic, allergen-mediated inflammatory disease of the esophagus, and the most common cause of prolonged dysphagia in children and young adults in the developed world. While initially undistinguished from gastroesophageal reflux disease-associated esophageal eosinophilia, EoE is now recognized as a clinically distinct entity that shares fundamental inflammatory features of other allergic conditions and is similarly increasing in incidence and prevalence. The clinical and epidemiologic associations between EoE and other allergic manifestations are well established. In addition to exaggerated rates of atopic dermatitis, IgE-mediated food allergy, asthma, and allergic rhinitis in EoE patients, each of these allergic manifestations imparts individual and cumulative risk for subsequent EoE diagnosis. As such, EoE may be a member of the "allergic march"-the natural history of allergic manifestations during childhood. Several determinants likely contribute to the relationship between these conditions, including shared genetic, environmental, and immunologic factors. Herein, we present a comprehensive review of allergic comorbidity in EoE. We discuss areas of the genome associated with both EoE and other allergic diseases, including the well-studied variants encoding thymic stromal lymphopoietin and calpain 14, among other "atopic" regions. We summarize ways that environmental factors (such as microbiome-altering pressures and aeroallergen exposure) may predispose to multiple allergic conditions including EoE. Finally, we touch on some fundamental features of type 2 inflammation, and the resulting implications for the development of multiple allergic manifestations. We conclude with an analysis of the "type 2" biologics, and how mechanistic similarities between EoE and the other allergic manifestations have important implications for screening and treatment of the allergic patient.

Clinical features of Helicobacter pylori antibody-positive junior high school students in Nagano Prefecture, Japan

BACKGROUND

Previously, we conducted an epidemiological study screening for Helicobacter pylori antibody positivity among Japanese junior high school students. In this study, we updated the epidemiological data and assessed the clinical features of H pylori antibody-positive junior high school students.

MATERIALS AND METHODS

We assessed H pylori antibody-positive subjects who were identified between 2012 and 2015 at four junior high schools in Nagano Prefecture, Japan. H pylori infection was confirmed by urea breath test (UBT) or endoscopic examination. Endoscopy was performed after obtaining consent from the subject and their guardians. Eradication therapy consisted of triple therapy with proton pump inhibitor (PPI), amoxicillin (AMPC), and clarithromycin (CAM) or metronidazole (MNZ) for seven days. Eradication of H pylori was confirmed by UBT. We reviewed subjects' characteristics, endoscopic findings, histological findings, eradication regimes, outcomes, and adverse effects.

RESULTS

The overall prevalence of H pylori antibody positivity was 3.2% (42/1298). We assessed thirteen H pylori antibody-positive subjects. Eight subjects had a family history of H pylori infection. Six subjects had abdominal pain, and two subjects had iron deficiency anemia (IDA). Twelve subjects underwent endoscopy; one subject had duodenal ulcer, eleven subjects had antral nodular gastritis, and six subjects showed grade 2 closed type atrophic border according to the Kimura-Takemoto classification. All subjects received eradication therapy; CAM was used in five subjects with CAM susceptibility as well as in three subjects with unknown information on CAM susceptibility, and MNZ was used in five subjects with CAM resistance. Eradication was successful in twelve subjects (one unconfirmed). There were three mild adverse effects (abdominal pain or diarrhea).

CONCLUSIONS

Helicobacter pylori test for junior high school students represents an opportunity to diagnose the peptic ulcer, iron deficiency anemia, and gastric atrophy.

Environmental factors and eosinophilic esophagitis

The incidence and prevalence of eosinophilic esophagitis (EoE) have markedly increased over the past 2 decades, outpacing increased detection of the disease. Although genetic susceptibility markers for EoE have begun to be elucidated, the rate at which EoE has increased in incidence suggests environmental factors predominate. Despite many advances in understanding of the pathogenesis of EoE, the cause of EoE is unknown. This article reviews the emerging data related to environmental risk factors for EoE. Many of these environmental factors are rooted in the theoretical framework of the hygiene hypothesis, specifically mediation of disease development through dysbiosis. Other hypotheses are based on associations that have been observed in studies of non-EoE allergic disease. We describe the evidence that early-life exposures, including antibiotic use, acid suppression, and cesarean delivery, can increase the risk of disease. We also describe the evidence that infectious agents, such as Helicobacter pylori, are inversely associated with disease. Current evidence on geographic risk factors, such as population density, climate zone, and seasonality, is reviewed. We also describe behavioral factors that have been evaluated. Limitations of the existing research are discussed, and recommendations for future areas of research, including assessment of gene-environment interaction, are presented.

Helicobacter pylori infection does not protect against eosinophilic esophagitis: results from a large multicenter case-control study

OBJECTIVES

Rising trends in eosinophilic esophagitis (EoE) have been repeatedly linked to declining Helicobacter pylori (H. pylori) infection, mostly in retrospective studies. We aimed to prospectively evaluate this inverse association.

METHODS

Prospective case-control study conducted in 23 centers. Children and adults naïve to eradication therapy for H. pylori were included. Cases were EoE patients, whereas controls were defined by esophageal symptoms and <5 eos/HPF on esophageal biopsies. H. pylori status was diagnosed by non-invasive (excluding serology) or invasive testing off proton pump inhibitor (PPI) therapy for 2 weeks. Atopy was defined by the presence of IgE-mediated conditions diagnosed by an allergist.

RESULTS

808 individuals, including 404 cases and 404 controls (170 children) were enrolled. Overall H. pylori prevalence was 38% (45% children vs. 37% adults, p 0.009) and was not different between cases and controls (37% vs. 40%, p 0.3; odds ratio (OR) 0.97; 95% confidence interval (CI) 0.73-1.30), neither in children (42% vs. 46%, p 0.1) nor in adults (36% vs. 38%, p 0.4). Atopy (OR 0.85; 95%CI 0.75-0.98) and allergic rhinitis (OR 0.81; 95%CI 0.68-0.98) showed a borderline inverse association with H. pylori infection in EoE patients. This trend was not confirmed for asthma or food allergy.

CONCLUSIONS

H. pylori infection was not inversely associated with EoE, neither in children nor in adults. A borderline inverse association was confirmed for atopy and allergic rhinitis, but not asthma of food allergy. Our findings question a true protective role of H. pylori infection against allergic disorders, including EoE.

The cultivable bacterial flora of the esophagus in subjects with esophagitis

BACKGROUND

The healthy human esophagus is colonized by bacteria similar to that of the oral mucosa. However, little is known about the microbiome of the esophagus in esophagitis or the possible role of bacteria in the inflammatory response.

AIM

To survey bacterial diversity and compare the microbiome of the esophagus in subjects with gastro-esophageal reflux disease (GERD) and eosinophilic esophagitis (EoE).

MATERIAL AND METHODS

Seventeen subjects diagnosed with GERD and 10 with EoE underwent endoscopic examination with brush sampling and biopsies from the oral cavity, upper and lower esophagus. The samples were cultivated on agar plates, and bacterial growth was identified to the genus or species level and semi-quantified.

RESULTS

Significantly higher numbers of bacterial groups or species were found in specimens from the lower esophagus in subjects with EoE compared to subjects with GERD (median 4 (range 1-7) vs. 2 (range 0-6), p < .0014). Sixteen vs. 14 different bacterial groups or species were found in subjects with GERD and EoE, respectively, mostly in sparse or very sparse amounts. Alfa-streptococci (viridans streptococci) were the most common bacteria in both groups. Streptococci were present in all of the EoE-subjects but only in approximately 75% in lower esophagus of the GERD-subjects, regardless of the sampling method.

CONCLUSION

Subjects with GERD had significantly less bacterial diversity in both oral and esophageal samples than EoE-subjects. Whether this discrepancy might be explained by an effect on the protective mucosal biofilm by the acidic content of the reflux in subjects with GERD remains unclear.

Epidemiology and Natural History of Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) has emerged over the past 2 decades as a major cause of upper gastrointestinal morbidity. Over this time, the epidemiology of EoE has also rapidly evolved. EoE has transformed from a rare case-reportable condition to disease that is commonly encountered in the gastroenterology clinic, hospital emergency room, and endoscopy suite. The incidence and prevalence are increasing at rates that outpace increased disease recognition. Current incidence estimates range from 5 to 10 cases per 100,000, and current prevalence estimates range from 0.5 to 1 case per 1000. We review the data and potential reasons behind this increase, examine risk factors, and identify important areas for research into disease etiology. The article also discusses the progression of EoE from an inflammatory to fibrostenotic phenotype. An accurate view of the natural history of EoE is central to discussions with patients regarding disease prognosis and decisions about long-term use of medical, endoscopic, and diet therapies. Progressive remodelling appears to be gradual, but not universal, and the duration of untreated disease is the best predictor of stricture risk. Ultimately, prospective, long-term outcome studies focusing on multiple aspects of disease activity are needed to fully understand the natural history of EoE.

Review: Prevalence and dynamics of Helicobacter pylori infection during childhood

INTRODUCTION

Long-term persistent Helicobacter pylori infection has been associated with ulceropeptic disease and gastric cancer. Although H. pylori is predominantly acquired early in life, a clear understanding of infection dynamics during childhood has been obfuscated by the diversity of populations evaluated, study designs, and methods used.

AIM

Update understanding of true prevalence of H. pylori infection during childhood, based on a critical analysis of the literature published in the past 5 years.

METHODS

Comprehensive review and meta-analysis of original studies published from 2011 to 2016.

RESULTS

A MEDLINE^® /PubMed^® search on May 1, 2016, using the terms pylori and children, and subsequent exclusion, based on abstract review using predefined criteria, resulted in 261 citations. An Embase^® search with the same criteria added an additional 8 citations. In healthy children, meta-analysis estimated an overall seroprevalence rate of 33% (95% CI: 27%-38%). Seven healthy cohort studies using noninvasive direct detection methods showed infection prevalence estimates ranging from 20% to 50% in children ≤5 and 38% to 79% in children >5 years. The probability of infection persistence after a first positive sample ranged from 49% to 95%. Model estimates of cross-sectional direct detection studies in asymptomatic children indicated a prevalence of 37% (95% CI: 30%-44%). Seroprevalence, but not direct detection rates increased with age; both decreased with increasing income. The model estimate based on cross-sectional studies in symptomatic children was 39% (95% CI: 35%-43%).

CONCLUSIONS

The prevalence of H. pylori infection varied widely in the studies included here; nevertheless, model estimates by detection type were similar, suggesting that overall, one-third of children worldwide are or have been infected. The few cohort and longitudinal studies available show variability, but most studies, show infection rates over 30%. Rather surprisingly, overall infection prevalence in symptomatic children was only slightly higher, around 40%. Studies including only one positive stool sample should be interpreted with caution as spontaneous clearance can occur.

Prevalence of eosinophilic esophagitis in patients with gastroesophageal reflux symptoms: A cross-sectional study from a tertiary care hospital in North India

BACKGROUND

Eosinophilic esophagitis (EoE) is being recognized increasingly all over the globe; Indian data is however sparse. We screened patients with symptoms of gastroesophageal reflux disease (GERD) for presence of EoE in them.

METHODS

Consecutive patients with symptoms suggestive of GERD underwent gastroduodenoscopy and esophageal biopsies, obtained from both the upper esophagus (5 cm below the upper esophageal sphincter) and lower esophagus (5 cm above gastroesophageal junction), as well as from any other endoscopically visible abnormal mucosa. Demographic and clinical characteristics, endoscopic findings, peripheral blood eosinophilic count, and history of use of proton-pump inhibitors (PPIs) were analyzed. Stool examination was done to rule out parasitoids. EoE was diagnosed if number of mucosal eosinophil infiltrate was >20 per high-power field. In the latter, Warthin-Starry stain was performed to rule out presence of H elicobacter pylori.

RESULTS

Of 190 consecutive patients with symptoms of GERD screened, esophageal biopsies were available in 185 cases. Of them, 6 had EoE, suggesting a prevalence of 3.2% among patients with GERD. On univariate analysis, history of allergy, non-response to PPI, and absolute eosinophil counts and on multivariable analysis, history of allergy and no response to PPIs were significant predictors of EoE. Presence of EOE did not correlate with severity of reflux symptoms.

CONCLUSION

In this hospital-based study from northern part of India, prevalence of EoE in patients with GERD was 3.2%. EoE should be considered as a diagnostic possibility, especially in those with history of allergy, no-response to PPI, and absolute eosinophil count of ≥250/cumm.

The influence of Helicobacter pylori on the ethnic distribution of esophageal eosinophilia

BACKGROUND

Environmental factors associated with ethnicity may contribute to the occurrence of eosinophilic esophagitis. Our study aimed to investigate the influence of Helicobacter pylori on the ethnic variation of esophageal eosinophilia in a large national sample of patients undergoing esophago-gastro-duodenoscopy.

METHODS

The Miraca Life Sciences Database is an electronic repository of histopathologic patient records. A case-control study evaluated the influence of ethnicity on the occurrence of esophageal eosinophilia and how age, gender, and histologic diagnosis of H. pylori modify this relationship.

RESULTS

The total study population comprised 596 479 subjects, of whom 25 969 harbored a diagnosis of esophageal eosinophilia. Young age, male sex, and H. pylori infection in declining order exerted the strongest influence on the occurrence of esophageal eosinophilia. In comparison with the population comprising of Caucasians and African-Americans, esophageal eosinophilia was less common among patients of African (OR=0.10, 95% CI=0.01-0.46), Middle Eastern (0.22, 0.15-0.31), East Asian (0.32, 0.26-0.38), Indian (0.28, 0.21-0.37), Hispanic (0.40, 0.37-0.43), or Jewish descent (0.58, 0.51-0.66), but more common among patients of Northern European descent (1.25, 1.07-1.45). With the exception of Northern Europeans, all ethnic subgroups were characterized by a higher prevalence of H. pylori than the comparison group. A low prevalence of H. pylori was significantly associated with a high prevalence of esophageal eosinophilia (R² =0.90, P<.001).

CONCLUSION

Esophageal eosinophilia prevalence markedly varies by patient ethnicity. As there is a strong inverse correlation between H. pylori and esophageal eosinophilia, H. pylori infection may be in part responsible for the observed ethnic distribution of esophageal eosinophilia.

ACG Clinical Guideline: Treatment of Helicobacter pylori Infection

Helicobacter pylori (H. pylori) infection is a common worldwide infection that is an important cause of peptic ulcer disease and gastric cancer. H. pylori may also have a role in uninvestigated and functional dyspepsia, ulcer risk in patients taking low-dose aspirin or starting therapy with a non-steroidal anti-inflammatory medication, unexplained iron deficiency anemia, and idiopathic thrombocytopenic purpura. While choosing a treatment regimen for H. pylori, patients should be asked about previous antibiotic exposure and this information should be incorporated into the decision-making process. For first-line treatment, clarithromycin triple therapy should be confined to patients with no previous history of macrolide exposure who reside in areas where clarithromycin resistance amongst H. pylori isolates is known to be low. Most patients will be better served by first-line treatment with bismuth quadruple therapy or concomitant therapy consisting of a PPI, clarithromycin, amoxicillin, and metronidazole. When first-line therapy fails, a salvage regimen should avoid antibiotics that were previously used. If a patient received a first-line treatment containing clarithromycin, bismuth quadruple therapy or levofloxacin salvage regimens are the preferred treatment options. If a patient received first-line bismuth quadruple therapy, clarithromycin or levofloxacin-containing salvage regimens are the preferred treatment options. Details regarding the drugs, doses and durations of the recommended and suggested first-line and salvage regimens can be found in the guideline.

Helicobacter pylori infection is associated with a reduced risk of developing eosinophilic oesophagitis

BACKGROUND

Eosinophilic oesophagitis (EoE) represents a chronic immune-antigen-mediated allergic disease of the oesophagus of still unknown aetiology. Environmental exposure has been postulated to play a pathogenetic role. Helicobacter pylori (H. pylori) infection has been inversely associated with allergic diseases including atopic dermatitis, asthma and allergic rhinitis and H. pylori may play a protective role in these conditions. Little is known about the relationship between EoE and H. pylori.

AIM

To investigate in a case-control study whether H. pylori infection is associated with a reduced risk of developing EoE.

METHODS

H. pylori infection was evaluated by serology in 58 [11(19%) female, 47 (81%) male, median age: 36.5 years, range 20-72 years] patients with a clinical and histologically proven diagnosis of EoE and 116 age and sex-matched controls (1 case: 2 controls). Antibodies against H. pylori were identified by enzyme-linked immunosorbent assay. Patients with H. pylori-specific IgG ≥ 30 enzyme immunounits were classified as H. pylori-positive.

RESULTS

3/58 (5.2%) patients with EoE had serological evidence of H. pylori infection (EoE - H. pylori current infection) and 5/58 (8.6%) reported prior eradication therapy for H. pylori infection (EoE - H. pylori former infection). The control group demonstrated significantly higher seroprevalence of H. pylori (37.9%, P < 0.0001) when compared to patients with EoE. EoE was inversely associated with H. pylori infection [odds ratio (OR) 0.24, 95% confidence interval (CI) 0.11-0.50].

CONCLUSION

Helicobacter pylori infection is inversely associated with EoE. Our results may contribute to further understanding the pathogenesis and evolving aetiology of EoE.

Helicobacter pylori and allergy: Update of research

Recently a lot of literature has been published about the possible preventive action of Helicobacter pylori (H. pylori) against allergy. The present review summarizes research data about the association between H. pylori and allergic diseases, as well as discusses possible hypotheses about the preventive action of H. pylori against atopy. There is evidence from observational studies to support a weak inverse association between prevalence of H. pylori infection and allergy. However, confounders like some unidentified socioeconomic factors, antibiotic use and others could bias the association. Although data from cohort studies point to a possible association of H. pylori with some of the allergic diseases, no definite proof for causal relationship has been clearly demonstrated yet. A biological mechanism proposed to explain the preventive action of H. pylori to allergy is reduced exposure to a major stimulus for the generation of Treg cells in individuals without H. pylori infection. In addition, H. pylori could be an indicator for changes in gut microbiome, reflecting the complex interaction between microbes and immune system.

Recent research advances in eosinophilic esophagitis

PURPOSE OF REVIEW

Eosinophilic esophagitis (EoE) is a chronic allergic disease triggered by food allergens with an increasing prevalence. This review highlights recent research advances in EoE with a focus on the literature of the past 18 months.

RECENT FINDINGS

The incidence of EoE in the black population is higher than previously suggested. A novel locus spanning CAPN14 is associated with EoE. Diagnostic tests utilizing an analysis of EoE-specific transcriptome have been improved. Standardized EoE symptom score systems have been established. Treatment trials show the promise and limitations of allergen avoidance, antiinflammatory reagents, and anti-interleukin-13 antibodies. Insights into disease mechanisms highlight the role of invariant natural killer T cells and group 2 innate immune cells. Epithelial barrier protein desmoglein 1, bone morphogenetic protein antagonist follistatin, neurotrophic tyrosine kinase receptor type 1, and CAPN14 have been defined as new potential therapeutic targets in EoE as regulators of the inflammatory interleukin-13-axis. The role of IgG4 in the disease mechanisms has been suggested.

SUMMARY

Genetic predisposition influenced by environmental factors increases EoE susceptibility. Research identifying the critical events leading to allergen sensitization and the esophagus-specific responses that drive EoE is evolving, and will lead to a better understanding of EoE and new therapeutic approaches for the disease.

Disease associations in eosinophilic oesophagitis and oesophageal eosinophilia

Eosinophilic infiltration into oesophageal tissue, typical of eosinophilic oesophagitis (EoE), has been described in several other conditions, including infections, hypersensitivity, and other autoimmune disorders. Since its description, EoE has been associated with an increasing number of diseases also characterized by tissue infiltration, including eosinophilic gastroenteritis and Crohn's disease. While an association between EoE and coeliac disease was previously reported, it is not supported by recent research. In contrast, EoE seems to be common in patients with a history of congenital oesophageal atresia, leading to hypotheses linking both disorders. The prevalence of EoE has also been shown to be eight times higher in patients with connective tissue disorders (CTDs), which has led to the proposal of an EoE-CTD phenotype, although this requires further assessment. This paper reviews the evidence of EoE's associations with several disorders, defining the common bases from an epidemiological, clinical, molecular and genetic perspective whenever possible.

Environmental and infectious factors in eosinophilic esophagitis

Identifying possible environmental or infectious etiologic factors for eosinophilic esophagitis (EoE) may offer insight into opportunities for disease prevention and treatment. We reviewed the current literature to assess environmental and infectious factors evaluated in EoE. Few studies have been conducted, however a consistent inverse association between EoE and H. pylori has been described. Several studies suggest a weak association between season and EoE diagnosis, but the evidence is inconclusive. EoE has also been associated with early life factors, including Cesarean delivery and antibiotic use. Larger studies are needed to evaluate these associations more thoroughly. Several papers have speculated the potential for anti-secretory agents to contribute to EoE. This has not been formerly evaluated. In summary, there is significant opportunity in the future to advance our understanding of possible environmental etiologic factors for EoE.

Recent advances in paediatric gastroenterology

Over the last few years, many changes have been introduced in the diagnosis and management of paediatric gastrointestinal problems. This review highlights the recent developments in Helicobacter pylori infection, eosinophilic oesophagitis, coeliac disease and inflammatory bowel disease.

Do We Know What Causes Eosinophilic Esophagitis? A Mechanistic Update

The mechanisms underlying eosinophilic esophagitis (EoE) have been intensely investigated, and significant advances have been made in understanding the pathogenesis of EoE. EoE is defined as a chronic immune/antigen-mediated disease, characterized clinically by symptoms of esophageal dysfunction and histologically by an esophageal eosinophilic infiltrate. In this paper, we will review the current knowledge of EoE pathophysiology based on both animal and human data and discuss possible etiologic mechanisms from the genetic and environmental perspectives. EoE is a Th2-predominant inflammatory process triggered by allergens. Proinflammatory cytokines and chemokines recruit eosinophils and other effector cells, such as mast cells, into the esophageal epithelium, where they cause direct damage and promote esophageal remodeling. The genetic expression profile of EoE has been described, and several single nucleotide polymorphisms have been identified and associated with EoE. While this genetic contribution is important, it is difficult to postulate that EoE is primarily a genetic disease. Given the rapid epidemiologic changes in the incidence and prevalence of EoE over the past two decades, environmental factors may be the driving force. While it is not known what causes EoE in an individual patient at a specific time, the current hypothesis is that there is a complex interaction between genetic factors and environmental exposures that remains to be elucidated.

Helicobacter pylori Infection in Pediatrics

This review includes the main pediatric studies published from April 2014 to March 2015. The host response of Treg cells with increases in FOXP3 and TGF-β1 combined with a reduction in IFN-γ by Teff cells may contribute to Helicobacter pylori susceptibility in children. Genotypic variability in H. pylori strains influences the clinical manifestation of the infection. Helicobacter pylori infection is associated with variables indicative of a crowded environment and poor living conditions, while breast-feeding has a protective effect. Intrafamilial infection, especially from mother to children and from sibling to sibling, is the dominant transmission route. Studies showed conflicting results regarding the association between H. pylori infection and iron deficiency anemia. One study suggests that H. pylori eradication plays a role in the management of chronic immune thrombocytopenic purpura in H. pylori-infected children and adolescents. The prevalence of H. pylori was higher in chronic urticaria patients than in controls and, following H. pylori eradication, urticarial symptoms disappeared. An inverse relationship between H. pylori infection and allergic disease was reported. Antibiotic resistance and insufficient compliance to treatment limit the efficacy of eradication therapy. Sequential therapy had no advantage over standard triple therapy. In countries where H. pylori infection is prevalent, studies focusing on virulence factors and antibiotic susceptibility may provide anticipation of the prognosis and may be helpful to reduce morbidity and mortality.

Clinical features of eosinophilic esophagitis: differences between Asian and Western populations

The prevalence and incidence of eosinophilic esophagitis (EoE) have been rapidly increasing in Western countries. It is thought to be more common among Caucasians than other racial or ethnic groups, but epidemiological studies have not been fully evaluated in Asian populations, and its clinical manifestation is rarely documented. In this review, recent reports regarding EoE in Asian countries have been collected, and differences in the clinical features, including symptoms and endoscopic findings, between Asian and Western populations have been evaluated. In Asia, EoE is still much less prevalent than in Western countries. Baseline values for average age, male/female ratio, and personal history of allergic disease were comparable to those in Western populations. Predominant symptoms were dysphagia, and food impaction was extremely rare among Asian patients. Although the frequency of abnormal endoscopic findings varies among studies, over 90% of patients with EoE have shown abnormal findings such as linear furrow, which is the most common findings, in recent prospective studies in Asia. There are few reports regarding the treatment of EoE and no prospective studies evaluating drugs or elimination diet in patient with EoE have been reported in Asia. Overall, EoE had similar clinical characteristics in Asian populations. Because the incidence of EoE could increase in the future with the increase in allergic disorders in Asian countries, large-scale, nationwide prospective studies should be performed to more fully understand the epidemiology and pathophysiology of EoE in Asian populations.