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.     

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.     

A reliable method for the simultaneous identification of H pylori and gastric metaplasia in the duodenum

While an association of Helicobacter pylori infection with duodenal mucosa gastric metaplasia has been described, the details and extent of the interaction are lacking. One of the limiting factors has been the lack of a staining technique that allows simultaneous visualisation of the bacteria and gastric metaplasia in the duodenum. This report describes a new stain that allows the simultaneous visualisation of duodenal gastric metaplasia and H pylori and compares the new stain with the component stains.     

Molecular resistance testing of Helicobacter pylori in gastric biopsies

OBJECTIVE: To evaluate simultaneous diagnosis of infection and molecular resistance testing of Helicobacter pylori. METHODS: Gastric biopsies were obtained from 26 rapid urease-positive and 51 rapid urease-negative test kits used to diagnose H pylori infection. Following glass bead-assisted DNA isolation, amplification of H pylori 16S ribosomal DNA (rDNA), glmM, and 23S rDNA target genes was performed. RESULTS: Helicobacter pylori DNA was successfully amplified from 100% (26/26) of urease-positive and 3.9% (2/51) of urease-negative gastric biopsies. Subsequent restriction enzyme-mediated digestion of 23S rDNA amplification products revealed that 17% (4/24) of urease-positive and H pylori DNA-positive biopsy specimens contained point mutations (A2142G or A2143G) associated with clarithromycin resistance. Helicobacter pylori DNA from gastric biopsies was successfully amplified 8 weeks following rapid urease testing. CONCLUSION: Helicobacter pylori genotyping may be used to detect macrolide-resistant H pylori in individuals prior to initiation of therapy or in patients refractory to anti-H pylori therapy. Two urease-negative specimens yielded Helicobacter DNA distinct from that of H pylori and indicated the need for further investigations of Helicobacter species present in the human stomach.     

Detection of Helicobacter pylori in gastric biopsy and resection specimens.

AIMS: To compare the sensitivity of detecting Helicobacter pylori in gastric biopsy and resection specimens using tinctorial and silver impregnation stains, immunohistochemistry and the polymerase chain reaction (PCR). METHODS: Formalin fixed, paraffin wax embedded tissue from 33 gastric biopsy specimens (26 showing chronic gastritis and seven showing low grade mucosa associated lymphoid tissue (MALT) lymphoma) together with blocks of uninvolved mucosa from gastrectomy specimens for MALT lymphoma (five cases) were studied. Consecutive sections were stained using haematoxylin and eosin, Giemsa, the Warthin-Starry silver stain, and a polyclonal antibody directed against H pylori using an immunoperoxidase technique following heat induced antigen retrieval. PCR analysis of DNA extracted from a further section was carried out using primers which amplified a 411 base pair fragment of the urease A gene. RESULTS: H pylori was detected in 14 (37%) sections stained with haematoxylin and eosin, 21 (55%) with Giemsa, 23 (61%) with Warthin-Starry, and 25 (66%) stained with the antibody. Seventeen (45%) cases were positive on PCR. Immunohistochemistry was positive in all cases in which H pylori was detected by other methods. CONCLUSION: Immunohistochemistry using an immunoperoxidase technique following heat induced antigen retrieval for detecting H pylori in gastric biopsy and resection specimens is highly sensitive and easy to use.     

Detection of Helicobacter pylori DNA in Fecal Samples from Infected Individuals

Stool, gastric biopsy, and serum samples were collected from 22 subjects. DNA from stool was extracted, amplified, and hybridized with primers specific for the 16S rRNA gene of Helicobacter pylori. DNA from gastric biopsy specimens was analyzed similarly for comparison. Universal primers were used to confirm successful extraction of DNA from samples. Histologic, serologic, and DNA analyses were scored in a blinded fashion. Universal primer amplification verified successful DNA extraction from all stool and gastric tissue specimens. The gastric tissue DNA assay was positive for H. pylori in 11 of the 22 subjects, correlating completely with histologic and serologic results. Stool DNA was positive for H. pylori by our molecular assay in 8 of these 11 H. pylori-positive subjects. All subjects who were negative by histologic, serologic, and gastric tissue DNA analyses were also negative by stool DNA analysis. Compared to histology, serology, and gastric tissue DNA analyses, the sensitivity of our stool DNA assay was 73%, with a specificity of 100%.     

Sulphomucins favour adhesion of Helicobacter pylori to metaplastic gastric mucosa.

AIMS: To assess the influence of sulphomucin secretion on Helicobacter pylori colonisation and adhesion to metaplastic gastric cells. METHODS: Gastric biopsies from 230 H pylori positive patients with intestinal metaplasia were analysed. Sulphated mucins and H pylori were visualised using a new technique combining high iron diamine-alcian blue mucin stains with the Steiner silver stain for the bacteria. RESULTS: Sulphomucin secretion anywhere in the mucosa and a histological diagnosis of dysplasia increase the risk of H pylori adhesion to metaplastic cells (odds ratios 19.9 and 4.3, respectively). However, only 9.4% of cases showing sulphomucin secretion and 10.8% of cases with dysplasia had evidence of adhesion of H pylori bacteria to metaplastic cells. CONCLUSIONS: The findings suggest that H pylori may play a role in the advanced stages of carcinogenesis. It will be of interest to investigate if the relative small proportion of type III metaplasias that actually progress to carcinoma show persistence of H pylori.     

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.     

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.     

Helicobacter pylori and gastric carcinoma

A retrospective study was performed on gastric carcinomas to establish the prevalence of Helicobacter pylori infection in gastric epithelium adjacent to the tumour. A total of 105 carcinomas were studied. The overall prevalence of Helicobacter pylori infection was 59%. The prevalence in different age cohorts from patients with gastric carcinoma was compared with that in patients suffering from non-ulcer dyspepsia and, based on serological testing, with that in healthy blood donors. The presence of Helicobacter pylori in cancer patients aged 41-50 and 51-60 was significantly higher than in blood donors. No difference was seen in comparison with non-ulcer dyspepsia patients. The presence of Helicobacter pylori showed an inverse correlation with the extent of intestinal metaplasia. The intestinal type of carcinoma was associated with a higher bacterial load than the diffuse type. These data suggest that the presence of Helicobacter pylori in gastric mucosa could play a role in the pathogenesis of gastric carcinoma, especially in the young age group.     

Helicobacter pylori in gastroduodenal diseases: Rapid identification by endoscopic brush cytology

Previous reports showed Helicobacter pylori (H. pylori) in type B gastritis-affected stomachs. This study was carried out to compare H. pylori staining effectiveness on biopsy to brush cytology. Tissue and brush parallel samples of gastric mucosa with abnormal or normal appearances were examined: 57.6% H. pylori-positive pieces from the antrum and 19.2% from the body were found, versus 65.3% and 25% H. pylori-positive brush smears, respectively. H. pylori resembling organisms were mainly related to chronic and acute antral inflammations and were often associated with higher amounts of round-shaped cocco-bacteria. In addition, H. pylori direct stain on brushing is proposed as the most rapid and reliable method for the routine diagnosis of Helicobacter pylori infection, in both ulcer or nonulcer gastritis.     

Effects of Helicobacter pylori on the cadherin-catenin complex

BACKGROUND: The cadherin-catenin complex is the key component of the adherens junction in epithelial cells, and changes in this complex are implicated in gastric adenocarcinoma. Germline mutations in E-cadherin have been described in diffuse-type gastric adenocarcinoma. Helicobacter pylori infection is the first stage in gastric carcinogenesis. AIMS: To determine whether H pylori was associated with changes in the complex, and whether this was affected by virulence of the strain. METHODS: Epithelial cell lines were cultured with H pylori using the wild-type pathogenic and non-pathogenic strains and CagE null and VacA null isogenic mutants. Gastric biopsy specimens at endoscopy were obtained from patients with (n = 17) and without (n = 15) H pylori infection, and E-cadherin and beta-catenin expression was assessed by immunohistochemistry. H pylori was typed by polymerase chain reaction from these patients for CagE and VacA. RESULTS: In vitro studies showed that coculture with a pathogenic strain of H pylori led to disruption of epithelial junctional beta-catenin expression, but without evidence of nuclear translocation or signalling. This effect was independent of a functional Cag pathogenicity island and vacuolating activity, but dependent on live bacteria. No marked differences in beta-catenin or E-cadherin expression were seen in gastric biopsy specimens in patients with and without H pylori infection. CONCLUSION: Acute H pylori infection disrupts junctional beta-catenin in vitro, but chronic infection by H pylori has no effect on E-cadherin and beta-catenin expression, as seen in gastric biopsy specimens at the initial gastritis stage of the proposed Correa pathway of gastric carcinogenesis. A later effect at the later stages of atrophy or intestinal metaplasia cannot be ruled out.     

Histopathological changes in gastric mucosa colonized by H. pylori

Helicobacter pylori (H. pylori), infection has been linked to acute and chronic gastritis, non-ulcer-dyspepsia, peptic ulcer, gastric adenocarcinoma and gastric non-Hodgkin's lymphoma of mucosa-associated lymphoid tissue (MALT). The epithelial changes in H. pylori colonized gastric mucosa are easy to recognize in routine Haematoxylin & Eosin stained sections and are so distinctive that they can serve as a helpful histological indicator for the presence of H. pylori in gastric biopsies. The histopathology of seventy-five gastric biopsies showing colonization by H. pylori was studied. Histologically, the H. pylori colonized gastric epithelium showed characteristic changes that were topographically related to the bacteria. These changes included irregular surface, epithelial pits, individual cell dropout and microerosion, which were specific for H. pylori colonization. These were absent in areas not colonized by H. pylori and in 20 consecutive H. pylori negative gastric biopsies seen during the same study period. As specific treatment for H. pylori infection is available, identification of H. pylori colonization in gastric biopsies should be attempted in all cases of gastritis, peptic ulcers and non-ulcer-dyspepsia.     

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.     

Antral histopathological changes in acid peptic disease associated with Helicobacter pylori

The histopathology of the antral mucosa of patients with acid peptic disease was studied in relation to Helicobacter pylori infection. Three hundred and fifty-five patients underwent gastroscopy and biopsy on 443 occasions. During each gastroscopy, two antral samples were taken for Rapid Urease Test (RUT) for H. pylori and two antral samples for histopathology. Haematoxylin and Eosin and modified Giemsa stained sections were studied. Histopathological changes in the antrum and the density of H. pylori were graded according to the Sydney System criteria. There was a significant association between the RUT and histology results for detection of H. pylori. The overall prevalence of H. pylori was 61.4% with a maximum incidence in the third and fourth decades of life, and an equal sex distribution. H. pylori colonisation was seen in 90.7% of patients with duodenal ulcer, 66.7% with gastric ulcer and 44.3% with non-ulcer dyspepsia. H. pylori colonisation was associated with more severe antral chronic active gastritis, lymphoid follicles, intestinal metaplasia and dysplasia. Elimination of H. pylori by treatment with anti-H. pylori regimens resulted in regression of the changes.     

Evaluation of diagnostic methods for Helicobacter pylori gastritis

The authors evaluated the use of direct Gram-stained smears, 1- and 24-hour urease broth tests, histologic examination, and culture to detect Helicobacter pylori in 100 gastric biopsy specimens from 97 patients with epigastric symptoms. Twenty-six patients had positive cultures and 27 had H. pylori identifiable in hematoxylin and eosin-stained sections. The gastric biopsy specimens from the 29 patients with culture and/or histologic findings positive for H. pylori showed active gastritis in 27 cases (93%), compared with 26 cases (37%) without H. pylori (P less than 0.0001). Chronic gastritis was present in 25 cases (86%) with H. pylori and 40 cases (56%) without H. pylori (P less than 0.01). Twenty patients had positive Gram-stained smears. Fifteen patients had positive 1-hour urease tests, and 3 had delayed positive 24-hour urease tests. There were no false-positive Gram's stain results, three false-positive 24-hour urease tests, two false-negative histologic results, and three false-negative cultures (one inadvertently incubated anaerobically). The sensitivities of the methods were as follows: 62% for the 24-hour urease test, 69% for direct Gram's stain, 90% for culture, and 93% for histologic examination. The authors conclude that the urease test used in this study has low sensitivity and limited specificity; that the direct Gram-stained smear is a useful, highly specific, rapid screening test; and that the lengthier methods of culture and histologic examination have comparably high sensitivity for the definitive diagnosis of H. pylori gastritis.     

The Helicobacter (Campylobacter) pylori-colonized duodenal mucosa and gastric metaplasia

Biopsies were obtained from non-ulcerated sites of the duodenum from 100 dyspeptic patients. Helicobacter (Campylobacter) pylori was cultivated from 19 of these biopsies. Active chronic duodenitis (ACD) was found in 17 biopsies and more than 5% gastric metaplasia in 20 biopsies. H. pylori as well as ACD occurred with a significantly increased frequency when more than 5% gastric metaplasia was found in the duodenal biopsies. H. pylori on metaplastic tissue without ACD was, however, seen in two cases. H. pylori was cultivated from 9% and ACD was found in 5% of the biopsies with less than 5% gastric metaplasia. Gastric metaplasia in the duodenum was found significantly more frequently in patients with endoscopic duodenitis or duodenal ulceration than in patients with normal endoscopy. No association between gastric metaplasia in the duodenum and gastric pH or serum antibodies against H. pylori was seen. This study indicates that there is an established, but not exclusive, connection between gastric metaplasia and the colonization of the duodenum by H. pylori, the most important role being played by the antral gastric mucosa rather than the duodenum.     

Use of Romanowsky type (Diff-3) stain for detecting Helicobacter pylori in smears and tissue sections.

A Romanowsky type (Diff-3) stain was used for identifying Helicobacter pylori in gastric biopsy specimens from 50 patients with ulcer and non-ulcer dyspepsia. Air dried smears were prepared from fresh biopsy tissue and histological sections were prepared from paraffin wax processed tissue. The Diff-3 technique is accomplished in five steps and takes about 30 seconds. Results using the Diff-3 stain correlated 100% with those using the Giemsa stain. The Diff-3 stain is reliable, simple, rapid, easy and clean, and smears prepared from fresh biopsy tissue can be examined and an immediate report given. The method is recommended for the identification of H pylori in smears prepared from fresh tissue as well as in sections prepared from processed tissue.     

Rapid and easy detection of Helicobacter pylori by in situ hybridization

Various in situ hybridization (ISH) methods have been used to identify Helicobacter pylori, a causative organism responsible for chronic gastritis and peptic ulcer disease, but they were hard to perform and time consuming. To detect H. pylori in a rapid and easily reproducible way, we developed synthetic biotinylated oligonucleotide probes which complement rRNA of H. pylori. Formalin-fixed and paraffin-embedded tissues from 50 gastric biopsy specimens were examined. Using a serologic test and histochemical stain (Warthin-Starry silver stain and/or Giemsa stain) as a standard, 40 of them were confirmed to be H. pylori-positive. Our ISH was quickly carried out within one hr and results were compared with those obtained from immunohistochemical stain. The ISH produced a positive reaction in 38 of 40 cases (95%). All H. pylori-negative cases failed to demonstrate a positive signal. The ISH has a sensitivity comparable to those of conventional histochemical and immunohistochemical stain, and has high specificity. In conclusion, ISH with a biotinylated oligonucleotide probe provides a useful diagnostic method for detecting H. pylori effectively in routinely processed tissue sections.     

Limited role of lipopolysaccharide Lewis antigens in adherence of Helicobacter pylori to the human gastric epithelium

In vitro and in vivo studies from various groups have suggested that Helicobacter pylori lipopolysaccharide (LPS) Lewis x (Le(x)) antigens mediate bacterial adhesion. We have now reevaluated this hypothesis by studying the adherence in situ of H. pylori strain 11637 and its corresponding Le(x)-negative rfbM mutant to human gastric mucosa from patients (n = 22) with various gastric pathologies. Significant binding of the parent strain was observed in only 8 out of 22 sections; in four out of eight patients, the Le(x)-negative mutant bound less well. One of these four patients displayed no gastric abnormalities, and the other three showed dysplasia, metaplasia, and adenocarcinoma, respectively; hence, we are unable to define the circumstances under which LPS-mediated adhesion takes place. We conclude that H. pylori LPS plays a distinct but minor role in adhesion.