Dyspeptic symptoms associated with Helicobacter pylori infection are influenced by strain and host specific factors

Association between genetic polymorphisms of NOD1, Interleukin-1B, and cagA strain with low-grade duodenal eosinophilia in Helicobacter pylori-related dyspepsia

BACKGROUND

Functional dyspepsia (FD) is a multifactorial disorder. Helicobacter pylori (H. pylori)-related dyspepsia (HpD) may be considered a separate entity. Duodenal eosinophilia is a potential pathogenic mechanism in FD. However, the impact of duodenal eosinophilia and host genetic polymorphism of innate and pro-inflammatory cascade, nucleotide-binding oligomerization domain 1 (NOD-1), and interleukin-1 beta (IL-1β) in HpD was not explored.

AIM

To evaluate the association of NOD1-796G>A and IL-1B-511C>T gene variants and low-grade duodenal eosinophilia in HpD.

METHODS

A multicenter cross-sectional study was conducted. A total of 253 patients who met Rome-IV criteria were selected before upper endoscopy and 98 patients were included after unremarkable upper endoscopy and positive H. pylori in gastric biopsies were assessed. Clinical parameters, H. pylori cagA and duodenal histology, were evaluated.

RESULTS

Sixty-four (65%) patients had epigastric pain syndrome (EPS), 24 (25%) postprandial distress syndrome (PDS), and 10 (10%) EPS/PDS overlap. FD subtypes were not associated with NOD1-796G>A and IL-1B-511C>T gene variants. Low-grade duodenal eosinophilia was significantly increased in NOD1-796 GG versus single A-allele, but not in IL-1B-511 single T-allele or CC-allele. This association is dependent of cagA infection, since harboring cagA strain was significantly associated with low-grade duodenal eosinophilia with isolated variants NOD1-796 GG and IL-1B-511 single T-allele, but not without cagA. When we performed combined polymorphism analysis with NOD1-796 GG/IL-1B-511 single T-allele, a synergistic effect on low-grade duodenal eosinophilia was found between these two loci irrespective of cagA strain status in HpD.

CONCLUSION

Our findings suggest that low-grade duodenal eosinophilia is significantly associated with NOD1-796 GG allele specially in cagA strain and with allelic combination NOD1-796 GG/IL-1B-511 single T-allele independent of cagA strain infection in HpD patients.

Low-grade duodenal eosinophilia is associated with cagA in Helicobacter pylori-related dyspepsia

BACKGROUND AND AIM

Functional dyspepsia (FD) is a multifactorial disorder. Helicobacter pylori (H. pylori)-related dyspepsia (HpD) may be considered a separate entity. Duodenal eosinophilia is a potential pathogenic mechanism in FD. However, the impact of duodenal eosinophilia and H. pylori virulence genes in HpD was not explored. We aim to evaluate the association of H. pylori virulence genes and low-grade duodenal eosinophilia in HpD.

METHODS

A multi-center cross-sectional study was conducted. A total of 301 patients who meet Rome-III criteria were selected before upper endoscopy, and 95 patients were included after normal endoscopy and positive H. pylori in gastric biopsies were assessed. Clinical parameters, H. pylori virulence genes (cagA, oipA, and vacA) and duodenal histology were evaluated.

RESULTS

Sixty-nine (72%) patients had epigastric pain syndrome (EPS), 17 (18%) post-prandial distress syndrome (PDS) and 9 (10%) EPS/PDS overlap. FD syndromes were not associated with cagA or oipA strains. A significantly trend of vacA s1/m1 (78%) and s1/m2 (80%) positive strains in EPS was observed. Histological duodenal grading of chronic inflammation, low-grade duodenal eosinophilia and intra-epithelial lymphocytes showed no difference in oipA and vacA strains. Low-grade duodenal eosinophilia was significant in cagA positive strain, and the OR for low-grade duodenal eosinophilia with H. pylori cagA positive strain was 4.2 (95% CI, 1.78-9.93). Adjusting for age, gender, smoking, diabetes, alcohol, PPI, and NSAID, the OR was 5.44 (1.989-14.902).

CONCLUSION

Our findings suggest that low-grade duodenal eosinophilia is significantly associated with cagA strain in HpD.

Impact of endoscopy-based research on quality of life in healthy volunteers

AIM: To study the impact of an endoscopy-based long-term study on the quality of life in healthy volunteers (HV).

METHODS: Ten HV were included into a long-term prospective endoscopy-based placebo-controlled trial with 15 endoscopic examinations per person in 5 different drug phases. Participants completed short form-36 (SF-36) and visual analog scale-based questionnaires (VAS) for different abdominal symptoms at days 0, 7 and 14 of each drug phase. Analyses were performed according to short- and long-term changes and compared to the control group.

RESULTS: All HV completed the study with duration of more than 6 mo. Initial quality of life score was comparable to a general population. Analyses of the SF-36 questionnaires showed no significant changes in physical, mental and total scores, either in a short-term perspective due to different medications, or to potentially endoscopic procedure-associated long-term cumulative changes. Analogous to SF-36, VAS revealed no significant changes in total scores for pathological abdominal symptoms and remained unchanged over the time course and when compared to the control population.

CONCLUSION: This study demonstrates that quality of life in HV is not significantly affected by a long-term endoscopy-based study with multiple endoscopic procedures.

Could gastric histology be a useful marker for making decision on Helicobacter pylori eradication therapy in patients with dyspepsia?

CONTEXT: It still remains an open debate whether Helicobacter pylori eradication is beneficial or not for the improvement of symptoms in functional dyspepsia. Differences in geographic distribution, the worldwide H. pylori genetic variability and the fact that the outcome of infection is strongly related to the virulence of the infecting strain are factors that might be driving ongoing controversies. OBJECTIVE: To study the correlation between gastric histology and H. pylori serology status in patients with dyspepsia. METHODS: This is a cross-sectional study where 40 consecutive dyspeptic patients (28 women and 12 men, mean age 48.5 years) with endoscopically normal stomachs were selected from the endoscopy unit at a university hospital in Recife, PE, Northeast of Brazil, between March 1998 and July 1999. Patients underwent gastric mucosal biopsy and serological tests (anti-Hp and anti-CagA antibodies). Gastric biopsies were examined using H-E and Giemsa stains and gastritis was classified and graded (mild, moderate or severe) according to "the updated Sydney System - Houston, 1994". RESULTS: Among 40 patients with dyspepsia the gastric histology revealed that about ¼ had moderate (25%) or severe (2.5%) gastritis. This subgroup of patients also had a greater positive frequency of anti-Hp (100% vs 41%; P = 0.0005) and anti-CagA (91% vs 58%; P = 0.09) antibodies when compared with those with normal histology (27.5%) or mild gastritis (45%). CONCLUSION: Since upper gastrointestinal endoscopy is part of the functional dyspepsia investigation and serology for anti-CagA antibody is not available in daily clinical practice, by biopsying gastric mucosa we would only be able to selectively apply H. pylori eradication therapy for those with histology that best correlate with virulent infecting strains (moderate or severe gastritis) - around ¼ of our study patients with dyspepsia.

Helicobacter pylori infection: a clinical overview

BACKGROUND

Helicobcater pylori colonizes the stomach of more than half of the world's population, and the infection continues to play a key role in the pathogenesis of a number of gastroduodenal diseases. Colonization of the gastric mucosa with Helicobcater pylori results in the development of chronic gastritis in all infected individuals and in a subset of patients chronic gastritis progresses to complications (i.e. ulcer disease, gastric neoplasias, some distinct extragastric disorders). The clinical outcome of the disease is dependent on many variables, including Helicobcater pylori genotype, innate host physiology, genetic predisposition and environmental factors. Helicobcater pylori eradication decreases the incidence of gastroduodenal ulcer and prevents its recurrence. Helicobcater pylori eradication for gastric cancer prevention has been suggested by preclinical research and clinical trials, showing even reversibility of precancerous lesions (atrophic gastritis and intestinal metaplasia) after Helicobcater pylori eradication.

AIMS

To review the current literature about H. pylori and its related pathologies.

CONCLUSION

At present, several clinical manifestations are recognized to be causally linked to Helicobcater pylori infection, and most of them can be cured by Helicobcater pylori eradication. Besides the relationship of Helicobcater pylori and gastroduodenal diseases, it has been well established that Helicobcater pylori infection is also involved in some extragastrointestinal diseases.

Effects of proton-pump inhibitors on functional dyspepsia: a meta-analysis of randomized placebo-controlled trials

BACKGROUND & AIMS

The aim of this study was to assess systematically the efficacy of proton pump inhibitors (PPIs) in the treatment of functional dyspepsia compared with placebo and to determine if any difference in the response exists between symptom subgroups of functional dyspepsia.

METHODS

A literature search was performed through September 2005 in PubMed, Medline, Embase, CINAHL, and Cochrane databases to include randomized, double-blind, placebo-controlled trials evaluating the efficacy of PPIs for the treatment of functional dyspepsia. Relative risk (RR) and relative risk reduction (RRR) and 95% confidence intervals (CI) were calculated under a random-effects model.

RESULTS

Seven studies with a total of 3725 patients were identified. PPIs were found to be more effective than placebo for reducing symptoms in patients with functional dyspepsia (RRR, 10.3%; 95% CI, 2.7%-17.3%). The estimated number needed to treat is 14.6 (95% CI, 8.7-57.1). When stratified analyses were performed, a significant difference in the efficacy was observed only in patients with ulcer-like (RRR, 12.8%; 95% CI, 7.2%-18.1%) and reflux-like dyspepsia (RRR, 19.7%; 95% CI, 1.8%-34.3%), but not in those with dysmotility-like (RRR, 5.1%; 95% CI, -10.9% to 18.7%) and unspecified dyspepsia (RRR, -8.0%; 95% CI, -23.7% to 5.6%). The effect of H pylori on the efficacy of PPIs remains unclear. Significant heterogeneity among studies was found for the overall analysis, dysmotility-like dyspepsia, H pylori-negative subgroup, and different dose subgroups.

CONCLUSIONS

PPIs are more effective than placebo for the management of patients with ulcer-like and reflux-like functional dyspepsia.

Clinical outcomes of eradication of Helicobacter pylori in nonulcer dyspepsia in a population with a high prevalence of infection: results of a 12-month randomized, double blind, placebo-controlled study

Ninety-one Helicobacter pylori-positive patients with nonulcer dyspepsia were randomized to receive either lansoprazole, amoxicillin, and clarithromycin or lansoprazole and placebo. A validated questionnaire assessed dyspeptic symptoms at baseline and at 3, 6, and 12 months. Endoscopies and biopsies were performed at baseline and at 3 and 12 months. There was an overall trend, although not statistically significant, for a benefit of H. pylori eradication. Of the patients in the antibiotics group, 16 of 46 (35%) had symptomatic improvement, versus 9 of 43 (21%) in the control group (P = 0.164). In a secondary analysis, it was found that of the patients without endoscopic gastric erosions, 15 of 34 (44%) in the antibiotics group and 5 of 33 (15%) of controls had symptomatic improvement (P = 0.015). Helicobacter pylori eradication did not prove to be clinically beneficial, although a tendency to symptomatic benefit was detected. Further studies are necessary to confirm the implications of endoscopic gastric erosions in these patients.

Pharmacogenetics‐Based New Therapeutic Concepts

Pharmacogenetics, one of the fields of clinical pharmacology, studies how genetic factors influence drug response. If hereditary traits are taken into account appropriately before starting drug treatment, the type of drug and its dosage can be tailored to the individual patient's needs. Pharmacogenetics adds a considerable amount of stringency to the doctor's therapeutic approach. Today, it is the relationship between dosage requirements and genetic variations in drug metabolizing enzymes like cytochrome P450 (CYP) 2D6 and CYP2C19, or in drug transporters like p-glycoprotein, that is substantiated best. A standard dose will bring about more adverse effects than usual if enzymatic activity is lacking or feeble. Sometimes, however, therapeutic response might be better due to higher concentrations: proton pump inhibitors for eradication of Helicobacter pylori are more efficacious in carriers of a deficient CYP2C19 variant. The drug's interaction with its target (e.g. receptor) also depends on genetic factors. In some cases genetic tests can help distinguish between responders and non-responders of a specific drug treatment. The first pharmacogenetic tests are already on the market.

Helicobacter pylori and nonmalignant diseases

This paper reviews the new literature from the past year on the association between colonization with Helicobacter pylori and non-malignant disease of the upper gastrointestinal tract. This issue has, in the past year, remained a topic of wide research interest yielding many important new data. These data show that H. pylori eradication is the most effective therapy for peptic ulcer disease, but that a considerable proportion of ulcer patients remain to have dyspeptic symptoms. The discussion on the interaction between H. pylori and NSAID use in the etiology of ulcer disease has not yet been settled. Several studies, both from Asia and Europe, now reported that H. pylori eradication has a minimal effect on the primary prevention of ulcer disease in NSAID users, but eradication appears of relevance for the secondary prevention of ulcer disease in addition to proton pump inhibitor maintenance therapy. Various studies brought further support for the hypothesis that H. pylori eradication is of some benefit for patients with non-ulcer dyspepsia, although the effects are limited. The prevalence of H. pylori is lower among GERD patients than among controls, but H. pylori eradication has not been consistently shown to increase the risk for the newly development of GERD in an individual subject undergoing H. pylori eradication. The discussion on H. pylori and GERD should not preclude us from treating H. pylori-infected patients for accepted clinical indications. In patients using proton pump inhibitors for GERD, H. pylori eradication leads to a resolution of their corpus-predominant pangastritis, without impairing the efficacy of PPI therapy.