Adherence of Helicobacter pylori to areas of type II intestinal metaplasia in Korean gastric mucosa.

The aim of this study was to examine whether Helicobacter pylori (H. pylori) attaches to areas of intestinal metaplasia in Korean patients. Gastric biopsy specimens with intestinal metaplasia from 8 gastric cancers, 24 gastric ulcers, 11 duodenal ulcers, and 57 chronic gastritis were examined. The specimens were stained with periodic acid-Schiff/alcian blue pH 2.5 and high-iron diamine/alcian blue pH 2.5 to identify the subtype of intestinal metaplasia, and then immunohistochemical stain was done with rabbit anti-H. pylori polyclonal antibody. In 17 patients, H. pylori attached to areas of type II intestinal metaplasia. All areas of intestinal metaplasia showing adherence contained sialomucin, and H. pylori was not detected in the areas of intestinal absorptive cells and sulfomucin-containing metaplastic cells.     

Clinicopathological features of duodenal bulb biopsies and their relationship with upper gastrointestinal diseases

AimTo assess the prevalence of the lesions in duodenal bulb mucosa and the relationship between duodenal lesions and upper gastrointestinal diseases, including helicobacter pylori infection.MethodsClinical, endoscopic and pathological data of the cases with duodenal bulb and gastric mucosal biopsy from January 2005 to May 2017 were analyzed retrospectively.ResultsA total of 3540 patients were enrolled. The biopsy from protuberant lesions with endoscopic morphology are mostly duodenal gastric heterotopia or adenoma. The biopsy from duodenal ulcers are often observed in inflammatory changes and gastric metaplasia.Patients with gastric heterotopia had a significantly lower prevalence of chronic atrophic gastritis, intestinal metaplasia, and gastric ulcer; and much higher prevalence of gastroesophageal reflux disease and gastric fundic polyps.Patients with gastric metaplasia had been positively associated with gastroesophageal reflux disease, and negatively associated with gastric fundic polyps.There were positive correlation between helicobacter pylori infection and duodenal active inflammation, Brunner gland hyperplasia, gastric metaplasia and duodenal ulcer. However, Patients with gastric heterotopia in bulb had been negatively associated with helicobacter pylori infection.ConclusionsThe mucosa lesions in duodenal bulb were associated with concurrent gastric fundic gland polyps, gastroesophageal reflux disease, duodenal ulcer, and helicobacter pylori infection.     

Histological study of chronic gastritis from the United Arab Emirates using the Sydney system of classification.

AIMS--To determine the prevalence of Helicobacter pylori in five main nationality groups with gastric ulcer, duodenal ulcer, and non-ulcer dyspepsia; and to determine the histopathological types of gastritis and assess the graded variables of Helicobacter associated gastritis. METHODS--Gastric antral and corpus biopsy specimens from 437 patients were examined for the prevalence of H pylori, 337 of which were classified and graded histologically according to the Sydney system. RESULTS--The overall colonisation rate of H pylori was 90%, and there was no significant difference between groups of different ethnic origins. The colonisation rates were 99%, 89%, and 78% in patients with duodenal ulcer, non-ulcer dyspepsia, and gastric ulcer, respectively. Helicobacter associated gastritis was the most common form of chronic gastritis (87%). H pylori density was greater in the antrum than the body. Gastric atrophy in helicobacter associated gastritis was seen in 54% of the cases (43% grade I, 10% grade II, 1% grade III) and increased the older the patients. Atrophy of the corpus alone was very rare (1%). Atrophy and intestinal metaplasia were more prevalent in patients with gastric ulcer than duodenal ulcer. CONCLUSION--The colonisation rate of H pylori was similar in the five groups studied and was almost invariably present in gastric biopsy specimens in patients with duodenal ulcer. H pylori associated gastritis was the most common form of gastritis. Atrophy was mainly of low grade and increased the older the patient.     

Duodenal bulb biopsy findings for patients with non-ulcer dyspepsia with or without Campylobacter pylori gastritis

Duodenal bulb biopsy specimens from 85 patients with non-ulcer dyspepsia (30 of whom had normal stomachs and 52 of whom had Campylobacter pylori gastritis) were examined for the presence and amount of gastric surface epithelial metaplasia (using both the hematoxylin and eosin stain and the Alcian blue-periodic acid-Schiff method), acute inflammation, and C. pylori (using the Giemsa stain). Gastric metaplasia occurred in the duodenal bulb in 61% of patients with gastric C. pylori and in an identical percentage for those who lacked C. pylori gastritis. For patients with gastric metaplasia, foci of metaplastic cells were seen in 70% of their bulb biopsy fragments. The Alcian blue-periodic acid-Schiff stain was superior to the hematoxylin and eosin stain for detecting gastric metaplasia. Only one of 33 patients without gastric C. pylori had gastritis and duodenitis. Fourteen of 52 (27%) patients with C. pylori gastritis had duodenitis; C. pylori was seen in the duodenal biopsy specimens from 13 of these patients. The organisms were often few, requiring oil immersion microscopy for detection. Each patient with duodenitis had gastric metaplasia, but some of these metaplastic foci were not inflamed. When present in the duodenum of patients with C. pylori gastritis, gastric metaplasia, acute inflammation, and C. pylori are typically patchy. Hence, several biopsy fragments of the duodenal bulb would be required for studies designed to determine the effectiveness of compounds used to treat C. pylori duodenitis.     

Chronic inactive gastritis and coccoid Helicobacter pylori in patients treated for gastroesophageal reflux disease or with H pylori eradication therapy

Gastric biopsy specimens from 105 consecutive adults with persistent dyspepsia who did not have changes due to esophageal reflux disease changes or gastric or duodenal ulcers at endoscopy were scored using the updated Sydney gastritis classification system. The medication history of proton pump inhibitors (PPIs) or Helicobacter pylori eradication therapy during the month before endoscopy was retrieved. Of the patients, 72 (68.6%) had chronic inactive gastritis, and 7 (6.7%) had antral-predominant, chronic mild active gastritis. H pylori infection was present in 36 patients (34.3%), of whom 29 had chronic inactive gastritis. Forty-six patients (43.8%) had a positive medication history, including 40 (56%) of 72 with chronic inactive gastritis. The most common morphologic feature associated with H pylori infection was moderate chronic inactive gastritis, which was found most often in patients who had received recent PPIs or H pylori eradication therapy. Pathologists should be aware of the extensive use of these medications, their association with chronic inactive gastritis, and rare H pylori thatfrequently are coccoid shaped. Modified Giemsa stain may not be the optimal method to detect H pylori in this group of patients.     

Gastric giardiasis.

AIMS: To assess the prevalence of gastric giardiasis in patients undergoing upper gastrointestinal endoscopy, and to define the clinicopathological correlates of gastric Giardia lamblia infection. METHODS: Consecutive gastric biopsy specimens (n = 15,023) from 11,085 patients, taken at Feltre City Hospital (north eastern Italy) from January 1986 to December 1991, were histologically and immunocytochemically examined for the occurrence of G lamblia trophozoites. Three gastric biopsy specimens from patients harbouring G lamblia infection, who repeated endoscopy before treatment, were also examined electron microscopically. RESULTS: Forty one patients (0.37% of the population study) harboured gastric giardiasis. All patients underwent upper gastrointestinal endoscopy because of dyspepsia, epigastric pain, or abdominal distension. Only two patients had diarrhoea at the time of investigation. Giardiasis was clinically unsuspected in all cases, although the nine patients who also had duodenal biopsies performed had concomitant intestinal giardiasis. Gastric giardiasis was invariably associated with chronic atrophic gastritis. Intestinal metaplasia of the gastric mucosa and Helicobacter pylori infection were found in 32 and 37 of the 41 patients with gastric giardiasis, respectively. CONCLUSIONS: The invariable association of gastric giardiasis with chronic atrophic gastritis, most often showing intestinal metaplasia and H pylori infection, indicates that a decreased gastric acidity is a prerequisite for localisation of G lamblia to the gastric mucosa. Though its possible role as a gastric pathogen remains to be elucidated, these findings suggest that trophozoites should be carefully searched for when examining gastric biopsy specimens showing chronic atrophic gastritis.     

Cytotoxin production by Helicobacter pylori from patients with upper gastrointestinal tract diseases.

A cytotoxin produced by some Helicobacter pylori strains has recently been identified. The cytotoxin induces intracellular vacuolization of cultured cells. The aim of the present study was to examine the frequency of occurrence of cytotoxin-producing strains of H. pylori from subjects with upper gastrointestinal disease including nonulcer dyspepsia, gastric and duodenal ulcer disease, gastroesophageal reflux disease, and gastric cancer. Broth culture filtrates of clinical isolates of H. pylori recovered from 175 patients were used to inoculate Vero and HeLa cell monolayers for the detection of vacuolating cytotoxin activity. The results obtained demonstrated that the highest percentage of strains producing cytotoxin were found in subjects with peptic ulcer disease (gastric ulcer, 65%; duodenal ulcer, 66%; P < 0.01 compared with nonulcer dyspepsia, 38%). Of the 11 patients with gastroesophageal reflux disease, 4 of 5 patients in this group who had esophageal ulcers, were found to be infected with strains that produced cytotoxin. Three of the four patients with carcinoma of the stomach were also found to be infected with cytotoxic strains of H. pylori. With increasing severity of mucosal damage in subjects with a normal upper gastrointestinal tract, macroscopic gastritis, duodenitis, and peptic ulceration, there were corresponding increase in the proportion of strains producing cytotoxin; these increases were 32, 46, 50, and 66%, respectively. H. pylori strains from subjects with ulcer disease commonly produced vacuolating cytotoxin, suggesting that it may be a virulence factor in the pathogenesis of peptic ulcer disease.     

Histology of chronic gastritis with and without duodenitis in patients with Helicobacter pylori infection.

AIM: To compare the histological characteristics of Helicobacter pylori positive chronic gastritis in patients with and without associated duodenitis. METHODS: Gastric mucosal biopsy specimens were obtained from patients undergoing endoscopy for dyspepsia. Severity of gastritis and density of H pylori infection were graded according to the Sydney system. RESULTS: Of the 69 patients studied, 15 had normal histology, 22 had chronic gastritis only (77.3% H pylori positive), 21 had duodenitis (90.5% H pylori positive), and 11 had other diagnoses. In the H pylori positive patients, the median gastritis score was higher in the duodenitis group (6, range 3-9) than in the chronic gastritis only group (5, range 2-8), because of greater neutrophil activity scores in patients with duodenitis (median score 2 v 1). There were no differences in the density of H pylori infection, inflammation, atrophy, or intestinal metaplasia between patients with chronic gastritis only and those with duodenitis. CONCLUSIONS: These results suggest that H pylori positive patients with duodenitis have a more severe form of gastritis than those without associated duodenal inflammation. This is because of increased neutrophil activity, which seems to be independent of the density of H pylori infection.     

Gastric epithelium in the duodenum: its association with Helicobacter pylori and inflammation.

Duodenal biopsy specimens from 471 adults and 47 children were examined to determine the prevalence and distribution of gastric epithelium in the duodenal bulb in relation to age, gender, gastroduodenal inflammation, smoking, alcohol and consumption of nonsteroidal anti-inflammatory drugs (NSAID). Gastric metaplasia was present in the anterior wall duodenal biopsy specimen in 31%, was significantly less common in patients under 17 than in adults, and was more common in males than females. In sixty two adults who underwent multiple radial duodenal biopsy gastric metaplasia was randomly distributed around the duodenal circumference; sixty three per cent of the patients with gastric metaplasia found on multiple biopsy were detected by just the anterior biopsy. Gastric metaplasia was not obviously associated with alcohol, cigarette, or NSAID consumption. While the presence of gastric metaplasia was associated with adulthood, male sex, and low fasting gastric juice pH, its extent was associated with active duodenitis and Helicobacter-associated gastritis. On logistic regression, gastric metaplasia in the duodenum and gastric Helicobacter pylori were independent predictors of active duodenitis, but were not significantly associated with inactive duodenal inflammation. H pylori was observed in duodenal biopsy specimens from 32 patients, all with active duodenitis; bacteria were present only on foci of gastric metaplasia, and were more likely to be seen when the metaplasia was extensive. It is proposed that inflammatory injury to the duodenal mucosa by H pylori may stimulate the development of further gastric metaplasia, and that the area of duodenum susceptible to colonisation with H pylori may therefore increase progressively until mucosal integrity is compromised and ulceration supervenes.     

Serologic detection of infection with cagA+ Helicobacter pylori strains.

Approximately 60% of Helicobacter pylori isolates possess the cagA gene and express its 120- to 140-kDa product (CagA). In this study, the cagA gene was detected in H. pylori isolates from 26 (81.3%) of 32 patients with duodenal ulcers (DU), 17 (68.0%) of 25 patients with gastric ulcers, and 23 (59.0%) of 39 patients with nonulcer dyspepsia (NUD). By Western blotting (immunoblotting) with antiserum to CagA, in vitro CagA expression was demonstrated for 95.5% of cagA+ strains compared with 0% of strains lacking cagA. Sera from patients infected with cagA+ strains (n = 66) reacted with recombinant CagA in an enzyme-linked immunosorbent assay to a significantly greater extent than either sera from patients infected with strains lacking cagA (n = 30) or sera from uninfected persons (n = 25) (P < 0.001). A strain lacking cagA was isolated from eight patients who had serum immunoglobulin G antibodies to CagA, which suggests that these patients were infected with multiple strains. Serum immunoglobulin G antibodies to CagA were present in 87.5, 76.0, and 56.4% of patients with DU, gastric ulcers, and NUD, respectively (odds ratio, 5.41; 95% confidence interval, 1.44 to 24.72; P = 0.004 [DU versus NUD]). These data demonstrate an association between infection with cagA+ H. pylori and the presence of duodenal ulceration and indicate that serologic testing is a sensitive method for detecting infection with cagA+ strains.     

Helicobacter pylori-induced chronic active gastritis, intestinal metaplasia, and gastric ulcer in Mongolian gerbils

The establishment of persisting Helicobacter pylori infection in laboratory animals has been difficult, but in 1996 Hirayama reported the development of a successful Mongolian gerbil model. The present study was undertaken with two aims: to better characterize the normal histological structure and histochemical properties of the gastric mucosa of the Mongolian gerbil; and to evaluate the progression of the histopathological features of H. pylori-induced gastritis in this animal model for one year after the experimental infection. Seventy-five Mongolian gerbils were used. Mongolian gerbils were sacrificed at 2, 4, 8, 12, 26, 38, and 52 weeks after H. pylori inoculation. Sections prepared from stomachs immediately fixed in Carnoy's solution were stained with hematoxylin and eosin and Alcian blue at pH 2.5/periodic acid-Schiff, a dual staining consisting of the galactose oxidase-cold thionin Schiff reaction and paradoxical Concanavalin A staining, and with immunostaining for H. pylori and BrdU. H. pylori infection induced in the Mongolian gerbil a chronic active gastritis, in which a marked mucosal infiltration of neutrophils on a background of chronic inflammation became detectable 4 weeks after inoculation and continued up to 52 weeks. Intestinal metaplasia and gastric ulcers appeared after 26 weeks in some of the animals, whereas others developed multiple hyperplastic polyps. The Mongolian gerbil represents a novel and useful model for the study of H. pylori-induced chronic active gastritis and may lend itself to the investigation of the epithelial alterations that lead to intestinal metaplasia and gastric neoplasia.     

Giardia lamblia trophozoites in gastric biopsies

To assess the prevalence of gastric giardiasis in gastric biopsies of patients with carcinoma stomach and in patients taking treatment for duodenal ulcer. Gastric biopsy specimens from 54 patients of carcinoma stomach and 100 antral biopsies from patients taking treatment for duodenal ulcer were included in the study. Sections were stained with haematoxylin and eosin, methylene blue and May Grunwald-Giemsa stains and examined for presence of Giardia lamblia trophozoites. Eight out of 54 (14.9%) biopsies of gastric carcinoma patients harboured trophozoites of Giardia lamblia. Associated H. pylori infection was present in all biopsies (8/8; 100%). Atrophy and intestinal metaplasia was present in 62.5% (5/8) and 25% (2/8) cases respectively. Sections from seven out of 35 patients (20%) taking treatment for duodenal ulcer showed presence of G. lamblia. H. pylori infection, gastritis and atrophy were found in 85.7% (6/7), 71.4% (5/7) and 28.6% (2/7) cases respectively. First gastric biopsy in these patients was negative for G. lamblia but 2nd and 3rd biopsies were positive. A careful search for G. lamblia trophozoites should be made while examining the gastric biopsies, especially in patients with carcinoma stomach, intestinal metaplasia, atrophic gastritis and those taking treatment for duodenal ulcer. This may help in indirect diagnosis of clinically unsuspected cases of intestinal giardiasis and may explain persistence of vague upper gastrointestinal tract (UGIT) symptoms despite clearance of H. pylori in patients on anti-ulcer therapy.     

Distribution of Helicobacter pylori colonisation and associated gastric inflammatory changes: difference between patients with duodenal and gastric ulcers.

AIMS--To determine the gastric distribution of Helicobacter pylori in patients with duodenal and gastric ulcers; and to examine the mucosal inflammatory response. METHODS--Patients with newly diagnosed, uncomplicated duodenal and gastric ulcers were endoscoped and two biopsy specimens each taken from the antrum and the body. Specimens were evaluated blind by one pathologist to determine H pylori activity (scored 0-3) and inflammatory changes (according to the Sydney classification). RESULTS--Adequate biopsy material was obtained from 40 and 44 patients with gastric and duodenal ulcers, respectively. Although antral colonisation with H pylori was more common in the antrum of the latter, the organism was equally likely to be found in the body of both sets of patients; the density of colonisation was higher in those with gastric ulcers. Active gastritis and mucosal atrophy were more common in the body of those with gastric ulcers; intestinal metaplasia was also more common in the antrum of these patients. CONCLUSIONS--Gastritis in patients with duodenal ulcers is mainly antral, but the incidence of gastric body colonisation with H pylori seems to be the same in patients with either type of ulcer. There is, however, a significant difference in colonisation density. The cause and importance of this are not obvious and may be related to either host or organism factors.     

Helicobacter pylori affects the quality of experimental gastric ulcer healing in a new animal model.

Helicobacter pylori has been implicated in the genesis of human gastritis, dyspepsia, and peptic ulcers. However, its influence in the quality of experimental gastric ulcer healing has not been previously investigated. Standardized gastric fundic ulcers were produced in 50 male Sprague-Dawley rats (150-200 g) by a 4 mm in diameter focal, serosal application of 100% acetic acid. Thirty rats were administered 2 ml H. pylori suspension (urease producing, ATCC 43504) in normal saline (10(8) CFU/ml) 2x/day for 7 days. Twenty rats (controls) received 2 ml normal saline 2x/day for 7 days. Gastric ulcer surface area was measured under a dissecting microscope and mucosal specimens were obtained for qualitative and quantitative histology. No gross or microscopic duodenal abnormalities were identified at sacrifice. Ninety percent of control rats showed grossly and microscopically entirely healed ulcers. The remaining 10% showed partially reepithelialized ulcers (area, 0.78 to 1.77 mm2; mean, 1.27 +/- 0.7 mm2). The grossly "healed" mucosa demonstrated marked dilatation of gastric glands lined with mature surface epithelial cells. Parietal cells were scanty (5-10% of all cells). One hundred percent of the H. pylori-exposed rats showed persistence of chronic active ulcers (area, 1.76 to 19.63 mm2; mean, 8.95 +/- 6.15 mm2). The ulcer beds were infiltrated by acute and chronic inflammatory cells, abundant fibroblasts, and capillary networks. The raised ulcer borders were characterized by dilated glands lined by mature surface epithelial cells. Various special stains demonstrated the presence of H. pylori in the surface mucus and within the crypts.(ABSTRACT TRUNCATED AT 250 WORDS)     

Helicobacter pylori associated gastric diseases and lymphoid tissue hyperplasia in gastric antral mucosa

AIM: To investigate the relation between Helicobacter pylori associated gastroduodenal diseases and lymphoid tissue hyperplasia in the antral mucosa and to pursue its evolution after eradication of H pylori. METHODS: Gastric antral biopsy specimens were obtained from 438 patients with H pylori positive gastroduodenal diseases (185 chronic gastritis, 69 gastric ulcer, and 184 duodenal ulcer) and 50 H pylori negative healthy controls. Lymphoid follicles and aggregates were counted and other pathological features were scored according to the updated Sydney system for classification of chronic gastritis. After a course of anti-H pylori treatment, biopsy specimens were obtained at four to six weeks, 12 months, and 24 months in the chronic gastritis patient group. RESULTS: The total prevalence of lymphoid follicles and aggregates in the biopsies was 79.9% (350 of 438; 95% confidence intervals (CI), 0.76 to 0.84). The prevalence and density of lymphoid follicles and aggregates were significantly different in the various gastroduodenal diseases. The highest prevalence (89.9%; 95% CI, 0.83 to 0.97) and density (0.82) of lymphoid follicles and aggregates occurred in patients with gastric ulcers. The lowest prevalence of lymphoid follicles and aggregates was found in patients with chronic gastritis (74.6%; 95% CI, 0.68 to 0.81), and the lowest density of lymphoid follicles and aggregates (0.56) was seen in patients with duodenal ulcers. The prevalence and density of lymphoid follicles and aggregates correlated strongly with the activity and severity of gastric antral mucosal inflammation. The eradication of H pylori resulted in a decrease in the prevalence and density of lymphoid follicles and aggregates. CONCLUSION: The prevalence and density of lymphoid follicles and aggregates in gastric antral mucosal biopsies correlated closely with H pylori infection.     

Association of Helicobacter pylori with gastritis and peptic ulcer diseases

The occurrence of Helicobacter pylori(H.pylori) and its relationship with gastric mucosa were studied by light and electron microscopy and culture of biopsy specimens from gastric mucosa of 160 patients with upper gastrointestinal symptoms. H. pylori were present in 96.6% of patients with active chronic gastritis, 100% of patients with duodenal ulcer and 76.9% of patients with gastric ulcer, while present in only 6.3% of individuals with histologically normal gastric mucosa. The bacteria colonized the antral mucosa more frequently than the body or than the duodenal cap mucosa. The bacteria were rarely seen in the intestinalized epithelium per se, but there was no significant difference in prevalence of H. pylori between gastritis with intestinal metaplasia and gastritis without intestinal metaplasia. H. pylori could be seen in close association with the surface of gastric epithelial cells below the mucus layer without evidence of intracellular parasitism, All of the strains tested were susceptible to penicillin, erythromycin, and most of them susceptible to tinidazole and bismuth salts. It is concluded that H. pylori are highly associated with gastritis and peptic ulcer diseases and its prevalence rates in patients with those diseases is higher than in developed countries. This strong association of H. pylori infection with gastritis and peptic ulcer diseases suggest a possible etiologic role for the bacterium in those diseases.     

Helicobacter heilmannii gastritis: association with acid peptic diseases and comparison with Helicobacter pylori gastritis.

We analyzed 2 antral and 1 corpus full-thickness random endoscopic gastric mucosal samples obtained from 946 patients with duodenal ulcers (6077 biopsies) and from 281 patients with nonsteroidal anti-inflammatory drug-associated gastric ulcers (1794 biopsies). We stained tissue sections with hematoxylin and eosin and Warthin-Starry silver stain and immunostained them with polyclonal antibodies against Helicobacter pylori. Hematoxylin- and eosin-stained sections from 6 patients with Helicobacter heilmannii (18 biopsies) and 23 randomly selected patients with H. pylori (68 biopsies) were evaluated and semiquantitated for the presence of acute inflammation, chronic inflammation, glandular atrophy, intestinal metaplasia, H. pylori, H. heilmannii, lymphoid follicles, or vasodilatation. Additional specimens were obtained for H. pylori culture, a CLO test, and serologic examination. H. heilmannii was detected in 6 (0.49%) of 1227 patients (14 [0.18%] of 7871 biopsies). Of these, 4 (0.42%) of 946 were patients with duodenal ulcers (9 [0.15%] of 6077 biopsies), and 2 (0.71%) of 281 were patients with nonsteroidal anti-inflammatory drug-associated gastric ulcers (5 [0.28%] of 1794 biopsies). We found H. heilmannii with hematoxylin and eosin stain, Warthin-Starry stain, and immunoperoxidase stain for H. pylori. Culture for H. pylori was negative in the four patients with duodenal ulcers. The CLO and serologic tests were positive in three of five and five of five patients, respectively. Our results indicate that H. heilmannii, like H. pylori, is associated with peptic ulcer disease (both active and inactive gastritis) and that it preferentially colonizes the gastric antrum. The severity of the H. heilmannii-associated gastritis is less intense and lymphoid aggregates are less common than in H. pylori-associated gastritis. Morphologic detection seems to be the method of choice for detecting H. heilmanni. Immunoperoxidase stain specific for H. pylori also stains H. heilmannii, indicating cross-reacting antigenic epitopes between H. heilmannii and H. pylori.     

Clinical and histological associations of cagA and vacA genotypes in Helicobacter pylori gastritis.

AIMS: To determine the relation among the cytotoxin associated gene (cagA) and vacuolating cytotoxin gene (vacA) status of Helicobacter pylori isolates, the associated clinical diseases, and the severity and pattern of chronic gastritis. METHODS: Helicobacter pylori was cultured from gastric biopsies obtained from dyspeptic patients. DNA was extracted from the isolates and the cagA and vacA status determined by the polymerase chain reaction (PCR). The prevalence of the different cagA and vacA genotypes in three clinical groups, duodenal ulcer, gastric ulcer, and non-ulcer dyspepsia was compared. The histological features in sections from two antral and two corpus biopsies were graded by one blinded observer. The grades were compared with age and sex matched groups with different cagA and vacA genotypes, and with duodenal ulcers, or non-ulcer dyspepsia. RESULTS: Isolates from 161 patients were included. One hundred and nine (68%) harboured a cagA+ strain and 143 (89%) harboured a vacA s1 strain. The prevalence of cagA+ strains in duodenal ulcer patients (94%) was highly significantly greater than in those with non-ulcer dyspepsia (56%). However, of the patients infected with a cagA+ strain, almost equal numbers had non-ulcer dyspepsia or peptic ulceration. Chronic inflammation, polymorph activity, surface epithelial degeneration, atrophy, and intestinal metaplasia were all significantly more severe in the cagA+ than in the cagA- group, whereas only corpus epithelial degeneration was significantly more severe in the vacA s1 group compared with the vacA s2 group. Patients infected with cagA+ strains were almost four times more likely to have antral intestinal metaplasia than cagA- patients. An antral predominant gastritis was present in duodenal ulcer patients compared with matched non-ulcer dyspepsia patients, but this was not attributable to cagA or vacA status. CONCLUSIONS: Helicobacter pylori strains showing cagA positively and the vacA s1 genotype are associated with more severe gastritis but these virulence factors do not appear to determine the overall pattern. The pattern is closely linked to clinical disease. Therefore, it is likely that the nature of the disease complicating chronic infection is determined by host and environmental factors, while bacterial factors determine the magnitude of the risk of developing such disease.     

The prevalence of lymphoid follicles in Helicobacter pylori associated gastritis in patients with ulcers and non-ulcer dyspepsia.

AIMS--To determine the prevalence of lymphoid follicles in Helicobacter pylori positive and negative gastritis in antral and body type gastric mucosa in patients with non-ulcer dyspepsia (NUD), duodenal ulcer, or gastric ulcer; to correlate follicle presence with patient age; to evaluate the correlation between the prevalence of lymphoid follicles and active and inactive gastritis and its severity; and to assess the positive predictive value of lymphoid follicle prevalence with respect to H pylori infection. METHODS--Gastric biopsy specimens, graded according to the Sydney system, from 337 patients were studied. RESULTS--Lymphoid follicles occurred more often in antral mucosa (78%) than in body type mucosa (41%) and were observed in 85% of patients with H pylori positive gastritis. There was no significant difference between NUD and gastric and duodenal ulcer disease with regard to the presence of lymphoid follicles. The positive predictive value of the presence of lymphoid follicles in H pylori infection was 96%. Lymphoid follicles were more commonly observed in patients aged between 10 and 29 years. Lymphoid follicles were more frequently found in pangastritis of all subtypes than in antral gastritis and also in active gastritis than in inactive gastritis. The presence of lymphoid follicles correlated strongly with the degree and severity of gastritis. CONCLUSION--Lymphoid follicles are a constant morphological feature of H pylori associated gastritis.