Geographical pathology of Helicobacter pylori infection: is there more than one gastritis?

IVTH BRAZILIAN CONSENSUS CONFERENCE ON HELICOBACTER PYLORI INFECTION

ABSTRACT Significant progress has been obtained since the III Brazilian Consensus Conference on H. pylori infection held in 2012, in Bento Gonçalves, Brazil, and justify a fourth meeting to establish updated guidelines on the current management of H. pylori infection. Therefore, the Núcleo Brasileiro para Estudo do Helicobacter pylori e Microbiota (NBEHPM), association linked to Brazilian Federation of Gastroenterology (FBG) held its fourth meeting again in Bento Gonçalves, RS, Brazil, on August 25-27, 2017. Twenty-six delegates, including gastroenterologists, endoscopists, and pathologists from the five regions of Brazil as well as one international guest from the United States, participated in the meeting. The participants were invited based on their knowledge and contribution to the study of H. pylori infection. The meeting sought to review different aspects of treatment for infection; establish a correlation between infection, dyspepsia, intestinal microbiota changes, and other disorders with a special emphasis on gastric cancer; and reassess the epidemiological and diagnostic aspects of H. pylori infection. Participants were allocated into four groups as follows: 1) Epidemiology and Diagnosis, 2) Dyspepsia, intestinal microbiota and other afections, 3) Gastric Cancer, and, 4) Treatment. Before the consensus meeting, participants received a topic to be discussed and prepared a document containing a recent literature review and statements that should be discussed and eventually modified during the face-to-face meeting. All statements were evaluated in two rounds of voting. Initially, each participant discussed the document and statements with his group for possible modifications and voting. Subsequently, during a second voting in a plenary session in the presence of all participants, the statements were voted upon and eventually modified. The participants could vote using five alternatives: 1) strongly agree; 2) partially agree; 3) undecided; 4) disagree; and 5) strongly disagree. The adopted consensus index was that 80% of the participants responded that they strongly or partially agreed with each statement. The recommendations reported are intended to provide the most current and relevant evidences to management of H. pylori infection in adult population in Brazil.

Impact of Helicobacter pylori infection and microscopic duodenal histopathological changes on clinical symptoms of patients with functional dyspepsia

AIM

To evaluate the microscopic histopathological changes in duodenal tissue and its relationship to the severity of symptoms in patients with functional dyspepsia while taking the effect of Helicobacter pylori (H. pylori) infection into account.

METHODS

Several gastric and duodenal biopsy specimens were obtained in 217 patients with functional dyspepsia and were evaluated for H. pylori infection and histopathological changes. Severity of symptoms was assessed by Leeds Dyspepsia Questionnaire (LDQ) and its relationship to histopathological changes and H. pylori infection status was assessed.

RESULTS

Helicobacter pylori infection was associated with presence and severity of microscopic duodenitis (p < 0.001). In H. pylori-infected patients, the presence of microscopic duodenitis was independent of microscopic gastritis (p = 0.74). Severity of dyspepsia symptoms was not higher in H. pylori-infected patients than non-infected patients (p = 0.15), but in the presence of H. pylori infection and microscopic gastritis, microscopic duodenitis significantly worsened the LDQ symptom severity score (p < 0.001). In multivariate analysis, the odds of experiencing severe symptoms in patients with severe microscopic duodenitis was 2.22 times greater than in individuals with very mild, mild, or moderate duodenitis.

CONCLUSIONS

Microscopic duodenitis in H. pylori-infected patients may play a major role in producing and aggravating symptoms in FD patients and may be a determinant factor to consider in whether to treat H. pylori infection in functional dyspepsia.

Absence ofHelicobacter pyloriin healthy laryngeal mucosa

Objectives:

To evaluate the presence ofHelicobacter pyloriin healthy laryngeal mucosa.

Design:

Prospective analysis ofHelicobacter pyloricolonisation in healthy laryngeal mucosa, using the13C urea breath test and polymerase chain reaction analysis.

Subjects:

Twenty randomly chosen men (28–78 years) without laryngeal pathology or gastrointestinal disease were investigated. All subjects were scheduled for elective operative procedures, under general, endotracheal anaesthesia. Cytobrush samples were taken forHelicobacter pyloriDNA detection. Nested polymerase chain reaction testing was performed on DNA solutions using two primer pairs from the urease A gene of theHelicobacter pylorigenome. The13C urea breath test was performed on two exhalation samples.

Results:

Eight (40 per cent) of the subjects were positive for urease on urea breath testing; none were positive forHelicobacter pyloriDNA on polymerase chain reaction testing.

Conclusion:

Based on these results, we do not considerHelicobacter pylorito be a normal constituent of healthy laryngeal microflora.

Differences in peptic ulcer between the East and the West

PUD affects both the East and the West. The magnitude of the problem, however, varies within these regions. The study of peptic ulcer epidemiology is impeded by the paucity of general population-based data, invasiveness of diagnostic tests, and variable access to testing facilities. As such, direct comparisons of PUD epidemiology between the East and the West are difficult. The prevalence rates of H pylori are highly variable and depend greatly on the local sanitation conditions. The use of NSAIDs and aspirin is ubiquitous and increasing especially for the antiplatelet activity of aspirin in the prophylaxis of cardiovascular events. There is evidence that pharmacogenetics play a role in susceptibility to the ulcerogenic properties of NSAIDs. The prevalence of PUD parallels the risk factors, but emerging in both the East and the West is idiopathic PUD, now a substantial proportion of ulcers in areas of declining H pylori infection. Genetic polymorphisms affect the efficacy of treatment using PPIs. Local H pylori resistance rates also influence the eradication success rates.

OLGA gastritis staging in young adults and country-specific gastric cancer risk

Geographical differences have been shown in the clinical outcomes of Helicobacter pylori-associated gastritis phenotypes and in gastric cancer risk. This study tested whether the Operative Link on Gastritis Assessment (OLGA) staging correlated with gastric cancer risk in populations from 3 continents. Mapped gastric biopsies were obtained from 316 dyspeptic adults aged less than 41 years from 8 geographic areas that differed in gastric cancer risk. Gastric atrophy was assessed according to internationally validated criteria. Gastritis stage was established according to the OLGA staging system. The most prevalent gastritis stages were 0 to II, which included all subjects entered from Chile, Germany, India, Italy, and Thailand. Gastritis Stages III and IV were limited to the Chinese and Korean populations. Indians had a high prevalence of H pylori infection without high-stage gastritis. In populations at different cancer risk, the gastritis OLGA stage mirrored the gastric cancer incidence. Gastritis staging identifies a subgroup of higher-risk patients.

Bactericidal and morphological effects of NE-2001, a novel synthetic agent directed against Helicobacter pylori

The antibacterial activities of NE-2001 were tested against 24 clinical isolates of Helicobacter pylori and compared with those of amoxicillin, clarithromycin, metronidazole, and furazolidone. The MIC(50) and MIC(90) of this synthetic compound on the isolates were 8 and 16 mug/ml, respectively. This action was highly selective against Helicobacter pylori; there was a >4-fold difference between the concentration of NE-2001 required to inhibit the growth of Helicobacter pylori and that required to inhibit the growth of common aerobic and anaerobic bacteria. Exposure of Helicobacter pylori (ATCC43504) to NE-2001 at the MIC (4 mug/ml), or at a greater concentration, resulted in an extensive loss of viability. The phenomenon was also observed at pH levels between 3.0 and 7.0. When two clinical Helicobacter pylori strains were successively cultured at subinhibitory concentrations of NE-2001, no significant changes in the bactericidal effects were found. The morphological alterations of Helicobacter pylori cells (ATCC43504), exposed to NE-2001 at various concentrations for 6 h, were observed using transmission electron microcopy. The bacterium displayed features such as swelling, vacuole-like structures in the cytoplasm, and cell destruction following exposure to NE-2001. The efficacy of NE-2001 was maintained when evaluated in eight clinical isolates resistant to metronidazole and five isolates resistant to both metronidazole and clarithromycin (MIC ranging between 4 and 16 mug/ml). The above-described results suggest that NE-2001 may have the potential to be developed as a candidate agent for the treatment of Helicobacter pylori infection.

Staging and grading of chronic gastritis

Chronic gastritis is an inflammatory condition of the gastric mucosa that may include structural alterations of the glandular compartment. The semiquantitative scoring systems advocated in the Sydney Systems and the subsequent Atrophy Club Guidelines remain essential for the recognition of the spectrum of the lesions detectable in gastric inflammatory disease. Most practicing pathologists, however, find them too cumbersome to use in their routine diagnostic activities. In this article, we propose a reporting system for chronic gastritis in staging and grading. Staging would convey information on the topography and extension of the gastric atrophic changes, whereas grading should represent the semiquantitative assessment of the combined severity of both mononuclear and granulocytic inflammation. This system could offer gastroenterologists a more immediate perception of the overall condition of the gastric mucosa while also providing useful information about gastric cancer risk.

Geographic pathology of Helicobacter pylori gastritis

BACKGROUND AND AIM

Helicobacter pylori is etiologically associated with gastritis and gastric cancer. There are significant geographical differences between the clinical manifestation of H. pylori infections. The aim of this study was to compare gastric mucosal histology in relation to age among H. pylori-infected patients from different geographical areas using the same grading system. The prevalence of atrophy and intestinal metaplasia were also compared with the respective gastric cancer incidence in the different countries.

METHODS

A total of 1906 patients infected with H. pylori from seven countries were evaluated. Entry criteria included H. pylori positive cases with antral and corpus biopsies between the ages of 18 and 75 years. The minimum number of cases required from a country was 100. Hematoxylin-eosin stained biopsies from antrum and corpus were scored semiquantitatively using the parameters suggested by the Sydney Classification System. Statistical evaluation was performed using Kruskal-Wallis test and Spearman's rank correlation test.

RESULTS

The severity of gastric atrophy varied among the different groups with the highest scores being present in Japan. The lowest scores were found in four European countries and in Thailand. The scores for intestinal metaplasia were low in general except for Xi-an, Japan, and Shanghai. For all the countries, the presence of atrophy in the antrum correlated well (r = 0.891) with the incidence of gastric cancer.

CONCLUSION

Using a standardized grading system in a large study of H. pylori-related geographic pathology, we found major differences in the overall prevalence and severity of H. pylori gastritis in relation to age. These differences mirrored the respective incidences of gastric cancer in those geographical areas.

Ethnic difference of Helicobacter pylori gastritis: Korean and Japanese gastritis is characterized by male- and antrum-predominant acute foveolitis in comparison with American gastritis

AIM: To investigate the clinicopathological factors underlying the ethnic differences of Helicobacter pylori gastritis and cancer.

METHODS: We analyzed clinicopathological parameters of gastric biopsies having H pylori infection that were randomly selected from different ethnic populations including 147 Americans, 149 Japanese, and 181 Koreans.

RESULTS: Males were predominant in Japanese and Korean populations (77.9 and 67.4% respectively) in comparison with Americans (48.3%) (P<0.001). H pylori gastritis in Koreans and Japanese was characterized by the predominant antral involvement. In the antrum, neutrophilic infiltration into the proliferative zone of pit, i.e., acute foveolitis, was more frequent in Koreans (82%) than in Japanese (71%) (P<0.05) and Americans (61%) (P<0.001). Interstitial neutrophilic infiltration, intestinal metaplasia and atrophy were also frequent in Koreans and Japanese. In the body, the prevalence of acute foveolitis was not significantly different among the populations while chronic interstitial inflammation and lymphoid follicles were more pronounced in the body of Americans than in the body of others (P<0.01).

CONCLUSION: The male-, and antrum-predominant H pylori gastritis in Koreans and Japanese is compatible with the pattern of sex and topographical distribution of gastric cancer incidence. Our data suggest that persistent acute foveolitis at the proliferative zone is a crucial step in the gastric carcinogenesis.

Comparison of different routes of vaccination for eliciting antibody responses in the human stomach

Determination of optimal routes to induce mucosal immune responses locally in the stomach and duodenum are important steps in the development of vaccines against Helicobacter pylori infection. In this study, we immunized H. pylori-infected individuals either nasally or rectally with a model antigen, i.e. cholera toxin B subunit, and compared the immune responses after these routes with the responses after oral or intrajejunal vaccination. Specific antibody levels in serum as well as specific antibody levels and antibody-secreting cells in biopsies from antrum and duodenum were determined by ELISA and ELISPOT methods. In contrast to oral vaccination, nasal and rectal vaccination did not induce significant increases in specific antibody-secreting cells either in the antrum or duodenum. Furthermore, when analyzing the antibody levels in saponin extracted biopsies, intrajejunal vaccination was superior to both nasal and rectal vaccination in inducing antigen-specific IgA levels in the stomach. We conclude that oral vaccination is the optimal route for induction of antigen-specific IgA antibody responses in the stomach and duodenum of humans, while nasal or rectal vaccination is less suitable for this purpose.

Review article: after gastritis--an imaginary journey into a Helicobacter-free world

This article explores the consequences of the world-wide trend that may result--at different times for different populations--in the disappearance of Helicobacter pylori and gastritis. After a brief historical introduction, some of the factors that contribute to the decrease in the prevalence of H. pylori are presented. The most apparent results of this trend in the industrialized world have been a decrease in the incidence of peptic ulcer and distal gastric adenocarcinoma. However, some other conditions of the upper digestive tract, such as acid reflux disease and adenocarcinoma of the cardio-oesophageal junction have been increasing. This simultaneous increase has led to the speculation that it may be causally related to the decreased prevalence of gastritis, and currents of thought supporting a laissez faire attitude with regards to H. pylori infection have developed. If these trends continue, future research aimed at understanding the pathogenesis of H. pylori-related conditions, including gastric carcinogenesis, will hinge on access to populations in which H. pylori is still highly prevalent, and on further refinement of the recently introduced Mongolian gerbil model.

The prevalence of Helicobacter pylori infection in benign laryngeal disorders

Helicobacter pylori (HP) is an accepted cause of chronic active gastritis and has a major causative role in peptic ulcers. It is a gastric carcinogen. Its role in nonulcer dyspepsia (NUD) is less clear, yet 50% of patients with NUD are infected with HP, and some recent literature demonstrates long-term improvement of symptoms following eradication. HP has been investigated in several other organ systems, but has not been investigated to any major degree in laryngeal disorders, a region that could be directly exposed to the bacterium from pharyngolaryngeal reflux. This study represents one arm of a larger study designed to investigate such a relationship. Of 101 patients with nonmalignant voice disorders presenting to our voice clinics, 54.5% tested positive for the H. pylori organism. Of the controls, 47.1% tested positive. When striated into age groups of < 45 years, 46-61 years, and > 62 years, and then age-matched with the controls, the likelihood of infection with the H. pylori organism was greater in both the experimental middle group, and in the middle group when combined with the elder group, than in the matched controls, and this difference demonstrated a trend approaching statistical significance. This finding is discussed in the light of other studies on HP and on gastroesophageal reflex (GER).

Geographic differences in the distribution of intestinal metaplasia in duodenal ulcer patients

OBJECTIVE

A strong correlation exists between atrophic gastritis and the intestinal type of gastric carcinoma. Duodenal ulcer disease characteristically has an antral predominant gastritis and a lower risk for gastric cancer. The aim of this study was to investigate the extent and distribution of intestinal metaplasia in duodenal ulcer in countries differing in gastric cancer incidence.

METHODS

Topographically mapped gastric biopsy specimens (median 11) were obtained from patients with duodenal ulcer in four countries (Korea, Colombia, USA, and South Africa). Sections were stained with a triple stain and evaluated for Helicobacter pylori (H. pylori), active inflammation, and intestinal metaplasia.

RESULTS

One hundred and sixty-five patients with duodenal ulcer were examined (29 from Korea, 52 from Colombia, 62 from the USA, and 22 from South Africa). The percentage of biopsies with intestinal metaplasia was significantly greater in Korean patients (86%) compared with that in other countries (50%) (p = 0.0004). Intestinal metaplasia was most prevalent in the antrum lesser curve and greater curve, and the body lesser curve. Intestinal metaplasia was present in the gastric corpus of 38% of duodenal ulcer patients from Korea compared with an average of 10% elsewhere (p = 0.018). No differences were observed in the density or distribution of H. pylori infection or in the degree of active gastritis between countries.

CONCLUSIONS

Although antral predominant gastritis is the prevalent pattern of gastritis in duodenal ulcer, intestinal metaplasia in the gastric corpus may be found with geographic differences. These findings suggest that duodenal ulcer and gastric cancer are not mutually exclusive diseases but are rather ends of the spectrum of H. pylori infection.

Concurrent enteric helminth infection modulates inflammation and gastric immune responses and reduces helicobacter-induced gastric atrophy

Helicobacter pylori is causally associated with gastritis and gastric cancer. Some developing countries with a high prevalence of infection have high gastric cancer rates, whereas in others, these rates are low. The progression of helicobacter-induced gastritis and gastric atrophy mediated by type 1 T-helper cells may be modulated by concurrent parasitic infection. Here, in mice with concurrent helminth infection, helicobacter-associated gastric atrophy was reduced considerably despite chronic inflammation and high helicobacter colonization. This correlated with a substantial reduction in mRNA for cytokines and chemokines associated with a gastric inflammatory response of type 1 T-helper cells. Thus, concurrent enteric helminth infection can attenuate gastric atrophy, a premalignant lesion.

Role of Helicobacter pylori gastritis in gastric atrophy, intestinal metaplasia, and gastric neoplasia

Helicobacter pylori is the major cause of chronic gastritis worldwide. With an estimated rate of infection of over one half of the world's population, it is responsible for extensive morbidity and mortality. Infection with this organism does not appear to spontaneously resolve. Instead it reaches a chronic stage from which a number of outcomes are possible. This article reviews those outcomes that have been linked to H. pylori and explores the pathogenesis while attempting to resolve the discrepant paths infection can take. The associations include duodenal and gastric ulcers and the majority of gastric lymphomas of B-cell type derived from the mucosa-associated lymphoid tissue (MALT). Chronic gastritis has also been shown to evolve into atrophy with intestinal metaplasia in certain populations. This change in the gastric epithelium has been linked with an increased risk of gastric adenocarcinoma. Microsc. Res. Tech. 48:313-320, 2000. Published 2000 Wiley-Liss, Inc.

Clinical relevance of the cagA, vacA, and iceA status of Helicobacter pylori

BACKGROUND & AIMS

Clinical outcome of Helicobacter pylori infection may be associated with specific virulence-associated bacterial genotypes. The aim of this study was to assess the relationships between H. pylori cagA, vacA, and iceA status and severity of disease.

METHODS

Gastric biopsy specimens from 94 patients in The Netherlands were analyzed by polymerase chain reaction and reverse hybridization.

RESULTS

cagA was present in 63 (67%) of 94 cases and was associated with peptic ulcer disease (P = 0.0019). vacA geno-types s1a/m1, s1b/m2, s1b/m1, s1b/m2, and s2/m2 were found in 36.2%, 23.4%, 2.1%, 5.3%, and 20.2%, respectively. Ten isolates (10.6%) contained multiple vacA genotypes. The presence of peptic ulcers was associated with type s1 strains (P = 0.0006) but not with the m type (P = 0.2035). cagA and vacA s1 were strongly associated (P < 10(-5)). iceA1 was found in 53 (56.4%) and iceA2 in 25 (26.6%) of the 94 cases. In 14 isolates (14.9%), both iceA alleles were found, and 2 (2.1%) were negative for both iceA1 and iceA2. iceA1 was also associated with peptic ulcer disease (P = 0.0042). The iceA allelic type was independent of the cagA and vacA status.

CONCLUSIONS

vacA s1, cagA, and iceA1 are markers of H. pylori strains that are more likely to lead to ulcer disease.

Typing of Helicobacter pylori vacA gene and detection of cagA gene by PCR and reverse hybridization

The present report describes an analysis of two virulence genes of Helicobacter pylori. Parts of the cagA gene, as well as parts from the signal (s) and middle (m) regions of the mosaic vacA gene, were amplified with biotin-labelled PCR primers and the products were subsequently analyzed by a single-step reverse hybridization line probe assay (LiPA). This assay comprises a strip containing multiple specific probes for the vacA s region (sla, slb, and s2 alleles), the vacA m region (ml and m2 alleles), and the cagA gene. A total of 103 H. pylori-positive materials, including cultured isolates, gastric biopsy specimens, and surgical specimens from patients living in Portugal (n = 55) and The Netherlands (n = 48) were tested by the PCR-LiPA. cagA was detected in 84 and 73% of the Portuguese and Dutch patients, respectively. vacA typing results, as determined by reverse hybridization, were completely concordant with those of sequence analysis. Most Portuguese patients (72%) contained type slb, whereas most Dutch patients (61%) contained type sla (P < 0.001). The method is also very effective at detecting the presence of multiple genotypes in a single biopsy specimen. The prevalence of multiple strains in Portuguese patient samples was significantly higher (29%) than that in Dutch patient samples (8%) (P = 0.001). There was a significant association between the presence of ulcers or gastric carcinoma and the presence of vacA type sl (sla or slb; P = 0.008) and cagA (P = 0.003) genes.

Histological classification of gastritis and Helicobacter pylori infection: an agreement at last? The International Workshop on the Histopathology of Gastritis

An international workshop has assessed and revised the Sydney System for the reporting of gastritis. Much of the original approach was retained including division into acute, chronic and special forms, and grading of chronic inflammation, polymorph activity, atrophy, intestinal metaplasia and H. pylori density into mild, moderate and marked categories. Visual analog scales have been introduced as a simple guide to grading. The four biopsy sites have been changed to optimize detection of H. pylori, and supplemented by a fifth biopsy from the incisura angularis, the site which is most likely to yield premalignant changes. Chronic gastritis is classified into non-atrophic and atrophic forms with the latter divided into autoimmune (diffuse corpus atrophy) and multifocal. Histological reporting of gastritis should take into account the topographical pattern (antral or corpus predominant), and the final diagnostic term should ideally combine morphology and etiology to maximize the clinical value of gastric biopsy diagnosis.

Recognizing atrophy: another step toward a classification of gastritis

The Sydney System is a novel classification of gastritis that attempts to incorporate etiologic, topographic, and morphologic criteria into a clinically relevant scheme. In September of 1994, a group of 20 gastric pathologists from various parts of the world gathered in Houston, Texas, U.S.A., to reappraise the Sydney System 4 years after its introduction and to attempt to reach a broad consensus on gastritis. One of the most controversial issues at the Houston Workshop was the concept of atrophy. Several factors converge to foment confusion and disagreement. "Normal" is imprecisely defined; the loss of glands occurs with distinct patterns and has different functional significance in antrum and corpus; inflammatory infiltrate and lymphoid follicles in the lamina propria may alter the architecture of the gastric mucosa, particularly in the antrum, making loss especially arduous to discern from mere displacement; the relationship between atrophy and intestinal metaplasia remains incompletely understood; and finally, and perhaps most important, the topographic patterns of distribution and the genesis and evolution of atrophic gastritis have been among the most divisive predicaments in the tumultuous arena of gastritis. This article explores some of the difficulties surrounding the concept of atrophy, summarizes the resolutions made at the Houston Workshop, and presents a novel approach to the histopathologic evaluation of atrophic gastritis.