Helicobacter pylori infection and reflux esophagitis in children with chronic asthma

Helicobacter pylori and Respiratory Diseases: 2021 Update

Helicobacter pylori (H. pylori) is a Gram-negative bacterium involved in the development of gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue. Unexplained iron deficiency anemia, idiopathic thrombocytopenic purpura and vitamin B12 deficiency have also been related to H. pylori infection, whereas for other extra-gastric diseases, the debate is still open. In this review, we evaluate and discuss the potential involvement of H. pylori infection in the pathogenesis of several respiratory diseases. A MEDLINE search of all studies published in English from 1965 to 2021 was carried out. Controversial findings have been reported in patients with bronchial asthma, chronic obstructive pulmonary disease, bronchiectasis, lung cancer, tuberculosis, cystic fibrosis, and sarcoidosis. Most of the available literature is concerned with case-control studies based on seroprevalence, with a small sample size and low consideration of confounders, which represents a potential issue. So far, there is no clear evidence of a causal association between H. pylori infection and respiratory diseases, and larger studies with appropriate epidemiological design are required.

Gastroesophageal reflux and respiratory diseases: does a real link exist?

INTRODUCTION

Gastro-esophageal reflux disease (GERD) indicates a gastroesophageal reflux that causes symptoms such as pain, and needs medical therapy, and may result in complications such as erosive esophagitis, aspiration pneumonia. Here, we review if it exists a real link between clinical presentation of some respiratory diseases such as asthma, chronic cough, cystic fibrosis and laryngopharyngitis and GERD.

EVIDENCE ACQUISITION

This review was conducted employing 2 databases: PubMed and Science Direct.

EVIDENCE SYNTHESIS

Asthma may lead to reflux, and reflux could exacerbate asthma or cause asthma-like symptoms. Prevalence of GERD in children with asthma ranged from as low 32% to as high 80%. There are several studies where the use of proton pump inhibitors (PPIs) and histamine H2 receptor antagonists lead to inconclusive results. The relation of chronic unexplained cough to GERD remains controversial in children and pediatric guidelines do not currently recommend empirical GERD treatment trials for pediatric chronic cough. Gastroesophageal reflux is more frequent in patients with cystic fibrosis (CF) than general population. Although PPIs are regularly prescribed in approximately half of the patients with CF, there are no specific guidelines for treatment of reflux in CF and it was shown that chronic treatment with PPIs was correlated to possible increased risk of exacerbations.

CONCLUSIONS

The pathogenesis of GER-related respiratory symptoms is multifactorial. The causal relationship between these two conditions may be difficult to prove also with the aid of supporting tests. Multichannel intraluminal impedance associated with pH-metry (pH/MII) detect all gastroesophageal reflux episodes accompanied with a bolus movement and classify GER episodes according to their content (liquid, gas and mixed), pH value and proximal extension. There are no consistent evidences confirming the validity of medical therapy in reflux with respiratory symptoms.

Choosing optimal first-line Helicobacter pylori therapy: a view from a region with high rates of antibiotic resistance

Helicobacter pylori is a gram-negative, microaerophilic spiral bacillus that is associated with life-threatening diseases such as gastric cancer, gastric MALT lymphoma, and peptic ulcer disease. The definition of an effective therapy is one that achieves at least a 90% eradication rate on a per-protocol basis with the first attempt. Eradication rates of H. pylori have declined to unacceptable levels worldwide, mostly due to antibiotic resistance and standard triple therapy gradually has lost its efficacy in most counties. However, bismuth quadruple therapy, when prescribed properly, has maintained its effectiveness. Alternative first-line regimens such as sequential and concomitant therapy were developed to substitute for standard triple therapy and were highly effective in the countries where they were developed, but proved susceptible to failure in regions with high rates of antibiotic resistance. Antibiotic resistance rates in Russia are high, however there is lack of data regarding comparative efficacy of first-line eradication options. The authors of this review extrapolate the knowledge of H. pylori first-line eradication options in Russia based on data from other countries, as well as from domestic studies. The available data support use of 14-day regimens with concomitant therapy, bismuth quadruple therapy, or furazolidone quadruple therapy for empiric use in adults. In addition, 14-day levofloxacin-containing therapies could be used if resistance is relatively low or lacking as triple therapy or possibly as a 5-day concomitant levofloxacin therapy.

Association between Helicobacter pylori and asthma: a meta-analysis

OBJECTIVE

Helicobacter pylori infection is recognized as a worldwide public health threat. Some studies have suggested that individuals with asthma have a lower rate of H. pylori infection, but the relation remains controversial. This meta-analysis was carried out to quantify the association between H. pylori infection and asthma.

METHODS

Published information on the prevalence of H. pylori in individuals with asthma was collected to assess the potential associations between H. pylori infection and the risk of asthma. Fourteen eligible studies were selected for analysis. Data on the study populations, detection method of H. pylori, and publication year were summarized. Meta-regression models and subgroup analyses were established to screen the factors resulting in heterogeneity.

RESULTS

Of the 106 articles retrieved, 14 fulfilled the inclusion criteria. The 14 studies involved 28 283 patients, with a total H. pylori infection rate of 40.53%. This meta-analysis found a significantly lower rate of H. pylori infection in the asthmatics than in the controls (odds ratio=0.84, 95% confidence interval: 0.73-0.96, P=0.013). Subgroup analysis indicated a similar infection rate of CagA-positive H. pylori infection in the asthmatic group and the control group (odds ratio=0.73, 95% confidence interval: 0.41-1.28, P=0.03).

CONCLUSION

The pooled data suggest that asthmatics have a significantly lower rate of H. pylori infection. Large-scale and multicenter studies should be carried out to further determine the relation between this bacterium and allergic disorders.

Helicobacter pylori CagA triggers expression of the bactericidal lectin REG3γ via gastric STAT3 activation

BACKGROUND

Most of what is known about the Helicobacter pylori (H. pylori) cytotoxin, CagA, pertains to a much-vaunted role as a determinant of gastric inflammation and cancer. Little attention has been devoted to potential roles of CagA in the majority of H. pylori infected individuals not showing oncogenic progression, particularly in relation to host tolerance. Regenerating islet-derived (REG)3γ encodes a secreted C-type lectin that exerts direct bactericidal activity against Gram-positive bacteria in the intestine. Here, we extend this paradigm of lectin-mediated innate immunity, showing that REG3γ expression is triggered by CagA in the H. pylori-infected stomach.

METHODOLOGY/PRINCIPAL FINDINGS

In human gastric mucosal tissues, REG3γ expression was significantly increased in CagA-positive, compared to CagA-negative H. pylori infected individuals. Using transfected CagA-inducible gastric MKN28 cells, we recapitulated REG3γ induction in vitro, also showing that tyrosine phosphorylated, not unphosphorylated CagA triggers REG3γ transcription. In concert with induced REG3γ, pro-inflammatory signalling downstream of the gp130 cytokine co-receptor via the signal transducer and activator of transcription (STAT)3 and transcription of two cognate ligands, interleukin(IL)-11 and IL-6, were significantly increased. Exogenous IL-11, but not IL-6, directly stimulated STAT3 activation and REG3γ transcription. STAT3 siRNA knockdown or IL-11 receptor blockade respectively abrogated or subdued CagA-dependent REG3γ mRNA induction, thus demonstrating a requirement for uncompromised signalling via the IL-11/STAT3 pathway. Inhibition of the gp130-related SHP2-(Ras)-ERK pathway did not affect CagA-dependent REG3γ induction, but strengthened STAT3 activation as well as augmenting transcription of mucosal innate immune regulators, IL-6, IL-8 and interferon-response factor (IRF)1.

CONCLUSIONS/SIGNIFICANCE

Our results support a model of CagA-directed REG3γ expression in gastric epithelial cells via activation of the IL-11/gp130/STAT3 pathway. This response might allow Gram-negative H. pylori to manipulate host immunity to favour its own survival, by reducing the fitness of co-habiting Gram-positive bacteria with which it competes for resources in the gastric mucosal niche.

Is Helicobacter pylori infection associated with asthma risk? A meta-analysis based on 770 cases and 785 controls

OBJECTIVE

Helicobacter pylori (H. pylori) infection has been thought to play a critical role in disorders such as gastric and lung cancer. A number of studies have been devoted to the relationship between H. pylori infection and asthma risk, which have generated inconclusive results. In this study we aimed to derive a more precise estimation of the relationship.

METHODS

Meta-analyses evaluating the association of H. pylori infection and asthma risk were conducted and subgroup analyses on ethnicity and source of controls as well as CagA status were further conducted. Eligible studies were identified for the period up to Jul 2012.

RESULTS

A total of five case-control studies comprising 770 cases and 785 controls were lastly selected for analysis. The overall data failed to indicate a significant association of H. pylori infection and asthma risk (OR=1.01; 95%CI=0.82-1.24). Likewise, in the subgroup analysis regarding ethnicity, source of controls and CagA status, no associations could be observed.

CONCLUSIONS

The pooled data failed to suggest a marked association between H. pylori infection and asthma risk. Future studies are needed to confirm this conclusion.

Clinical features of asthma in children differ with regard to the intensity of distal gastroesophageal acid reflux

BACKGROUND

The prevalence of gastroesophageal reflux (GER) in children with asthma is higher than in healthy controls, but the nature and direction of this association is unclear.

OBJECTIVE

The aim of our study was to assess the relationship between esophageal acid exposure and the clinical features of asthma in children.

METHODS

In total, 66 children (mean age 122.8 months [SD 44.89 months]) with chronic pulmonary symptoms, fulfilling diagnostic criteria of persistent asthma, underwent 24-hour esophageal pH monitoring and answered a detailed questionnaire-based survey. The questionnaire topics included environmental factors, familial history, current and previous clinical symptoms, atopy, asthma severity, and medication.

RESULTS

Abnormal results of 24-hour esophageal pH monitoring were found in 28 out of 66 children (42.4%). Age, sex, severity of asthma, environmental factors, spirometry results, and the type of medication did not correlate with esophageal acid exposure. However, children with abnormal pH results developed asthma significantly earlier (asthma onset 3.63 years [SD 2.52 years] vs 5.77 years [SD 3.82 years]; p < .01). Nonatopic individuals had more intensive esophageal acid exposure than atopic ones (Boix-Ochoa score 28.19 [SD 18.26] vs 18.26 [SD 12.84]; p < .048). The intensity of GER was also significantly correlated with frequent or difficult-to-control nighttime asthma attacks.

CONCLUSIONS

There are differences in clinical features of asthma in children with regard to the intensity of esophageal acid exposure. Symptoms of asthma in nonatopic individuals with early onset and difficult-to-control nighttime asthma attacks suggest the possibility of concomitant, clinically relevant GER.

Gastroesophageal reflux and asthma in children: a systematic review

CONTEXT

The relationship between gastroesophageal reflux disease (GERD) and asthma in children has been investigated; however, the nature of the association (if any) between these 2 conditions is unclear.

OBJECTIVE

We performed a systematic review of the literature to examine the association between GERD and asthma in children.

METHODS

A search of the medical literature was conducted by using PubMed and Embase (1966 through December 2008). Full-length articles in English that described at least 20 subjects younger than 18 years were included if they reported the prevalence of GERD (symptoms, pH studies, endoscopy/histology) in individuals with asthma or the prevalence of asthma in individuals with GERD. We calculated pooled odds ratios from studies that examined control groups, and we pooled prevalence estimates from all studies.

RESULTS

A total of 20 articles that described 5706 patients fulfilled the inclusion and exclusion criteria. Seventeen studies used objective methods for documenting reflux (eg, pH probe, contrast imaging, impedance, esophagogastroduodenoscopy), 2 studies relied on symptom-based questionnaires, and 1 study used diagnostic codes. Most studies (n = 19) examined the prevalence of GERD in 3726 individuals with asthma and reported highly variable estimates (19.3%-80.0%) and a pooled average of 22.8% with GERD symptoms, 62.9% of 789 patients with abnormal esophageal pH, and 34.8% of 89 patients with esophagitis. Only 5 studies included controls and enrolled 1314 case-patients with asthma and 2434 controls without asthma. The average prevalence of GERD was 22.0% in asthma cases and 4.8% in controls (pooled odds ratio: 5.6 [95% confidence interval: 4.3-6.9]).

CONCLUSIONS

There is a possible association between GERD and asthma in pediatric patients seen with asthma in referral settings. However, because of methodologic limitations of existing studies, the paucity of population-based studies, and a lack of longitudinal studies, several aspects of this association are unclear.

Helicobacter pylori seroprevalence in patients with chronic obstructive pulmonary disease and its relation to pulmonary function tests

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a slowly progressive condition characterized by poorly reversible airflow limitation that is associated with an abnormal inflammatory response of the lung. It has been shown that there is a seroepidemiological association of Helicobacter pylori (Hp) infection with many inflammatory conditions.

OBJECTIVE

In this study, we aimed to investigate seroprevalence in Hp patients with COPD and to determine whether there is an association between Hp infection and COPD.

METHODS

Forty-nine voluntary patients with COPD and 50 healthy control subjects of similar age and sex were included in the study. Hp-specific IgG was measured with a commercially available kit from venous blood samples.

RESULTS

Serum levels of Hp-specific IgG and Hp IgG seropositivity were significantly higher in the patients with COPD than in the control subjects (p < 0.001 and p = 0.006, respectively). In addition, when the patients with COPD were grouped according to Hp IgG seropositivity, forced expiratory volume in 1 s (FEV(1)) values were lower in the seropositive patients compared to seronegative patients, and Hp serum IgG levels were correlated with FEV(1) values, which indicate the severity of COPD, in the COPD group (r = -0.306, p = 0.032).

CONCLUSION

The results suggest that there is an association between Hp infection and COPD, and Hp IgG levels are correlated with the severity of COPD.

Helicobacter pylori infection in pediatrics

The proposed route of Helicobacter pylori transmission appears to be fecal-oral, oral-oral and gastro-oral, yet, a number of studies challenged these hypotheses in 2003. The use of the stool antigen test and[13]-C urea breath testing were the tests of choice for diagnosis and 'test for cure' of H. pylori in Europe in 2003 but have not yet become accepted standard of care in North America. Pediatric H. pylori consensus guidelines are not yet revised; upper endoscopy and biopsy remain the gold standard for diagnosis of pediatric H. pylori infection. In addition to stronger evidence supporting the role of host influences of H. pylori-associated gastric cancer risk, compelling evidence was provided for the role of H. pylori in iron deficiency anemia of childhood. Antibiotic resistance remains a problem in conferring treatment failure and 2003 studies indicate that macrolide resistance is higher in children than in adults. Treatment with proton pump inhibitor-based triple therapy for 10-14 days remains the mainstay for eradication of H. pylori in childhood. Finally, multinational studies are needed to develop screening guidelines for childhood infection to avoid long-term severe gastroduodenal disease sequelae.

Relationship of Helicobacter pylori related gastritis, gut hormones and gastroesophageal reflux disease

AIM: To evaluate the relationship of H. pylori infection, H. pylori -related gastritis, serum gastrin and motilin levels and esophageal lesions in gastroesophageal reflux disease (GERD).

METHODS: All 53 GERD patients were divided into non-erosive reflux disease (NERD group, 32 cases) and reflux esophagitis (RE group, 21 cases ) by endoscopy. The degrees of gastritis in antrum and body as well as esophagitis were evaluated by pathological examinations. Fasting serum gastrin and motilin concentrations were determined by radioimmunoassay. H. pyloriwas examined by serum H. pylori-antibody, Warthin-Starry stain, urease-dependent test (rapid urease test or ¹⁴C-breath test).H. pylori infection was affirmed when at least two of three tests were positive. 20 normal persons were as controls. In NERD group, 18 were H. pylori positive and 14 were negative. In RE group 12 were H. pylori positive and 9 were negative. According to the classification of esophagitis, 11 were ClassⅠ, 7 ClassⅡ and 3 Class Ⅲ. There were 30 H. pylori (+) and 23 H. pylori (-) in 53 GERD patients.

RESULTS: As compared with healthy controls, fasting serum motilin levels in RE group were significantly lower (360±126 vs 440±110 mg/L, ^aP < 0.05) and those in NERD group were similar (P > 0.05). No differences in gastrin levels were found between NERD or RE group and controls (both P > 0.05). The serum gastrin levels in H. pylori (+) GERD were significantly higher than controls (35.8±11.6 vs 28.5±10.6 mg/L, ^bP < 0.05). In H. pylori (+) GERD patients, gastritis grades in the antrum and gastric body were significantly higher than that in H. pylori (-) patients (χ² = 32.97, χ² = 15.67, both P < 0.005). The esophagitis grades were similar in H. pylori (+) and H. pylori (-) GERD (χ² = 0.82, P > 0.05). The gastritis grades were not associated with the esophagitis degrees, but with H. pylori infection.

CONCLUSION: Motilin is involved in the pathogenesis of RE. H. pylori can lead to hypergastrinemia and gastritis in the antrum and gastric body.