Decrease of antigastric autoantibodies in Helicobacter pylori gastritis after cure of infection.

H. pylori infection leads to the formation of autoantibodies against canalicular structures with human parietal cells in about 30% of all patients. This type of autoreactivity is associated with gastric mucosa atrophy. This study aimed to analyse the effect of cure of infection on anticanalicular autoantibodies. H. pylori infection was cured in 34 patients. Sera of these patients were screened for anticanalicular autoantibodies using an immunohistochemical method before, 10 weeks after and one year after cure of infection. Prevalence of anticanalicular autoantibodies significantly decreased from 26% before treatment to 9% after one year. The data presented in this study add new information to the possible reversibility of gastric mucosa atrophy.     

Significant increase in antigastric autoantibodies in a long-term follow-up study of H. pylori gastritis

In 30% of H. pylori-infected patients a certain type of antigastric autoantibodies, reacting against canalicular structures within human parietal cells, is detectable. Furthermore, it has been shown that these autoantibodies are correlated with atrophy of the mucosa in the corpus. The aim of this study was to analyse the prevalence of these anticanalicular autoantibodies (ACAB) and their significance for development of gastric mucosa atrophy in a 12-year follow-up period. Gastric biopsy specimens from 62 persons in Saaremaa Island, Estonia, were collected in 1997 and assessed independently by two pathologists in accordance with the updated Sydney system. The sera of these persons were immunohistochemically screened for ACAB and for classic parietal cell antibodies (PCA). In addition, for 37 of the 62 persons, gastric biopsies and sera collected 12 years earlier (1985) were investigated in an analogous manner. ACAB increased significantly, from 8 out of 37 in 1985 to 17 out of 37 in 1997 (P=0.004; McNemar test). In 1997 a significant correlation existed between the presence of ACAB and corpus mucosa atrophy (19 out of 30 versus 10 out of 32 without atrophy; P=0.01; odds ratio (OR)=3.8, 95% CI 1.4–10.6). However, no correlation was found between ACAB and development of atrophy in the period from 1985 to 1997. All 37 persons were PCA negative in 1985, whereas in 1997, 2 turned out to be PCA positive. ACAB increased significantly with duration of H. pylori gastritis. The correlation between ACAB and presence of gastric corpus atrophy was confirmed. However, it is possible that ACAB are the consequence of and not a causative factor in gastric mucosa atrophy, insofar as the association of ACAB with progression of corpus atrophy was not significant. Received: 20 October 1999 / Accepted: 13 January 2000     

Apoptosis in chronic gastritis and its correlation with antigastric autoantibodies

 In the course of time, chronic gastritis may result in gastric atrophy, as in type A gastritis, where autoimmune reactions against parietal cells result in a loss of corpus glands. Two antigastric autoantibodies have been detected in Helicobacter pylori gastritis and are described as anti-luminal and anti-canalicular autoantibodies. The aim of this study was to determine whether increased apoptosis may be responsible for the loss of gastric epithelium and whether this apoptosis is correlated with antigastric autoimmunity. Gastric biopsies from normal mucosa and Helicobacter pylori gastritis were analysed for the presence of apoptosis using the TUNEL method. Helicobacter pylori gastritis was divided into cases (1) without autoantibodies, (2) with anti-luminal, and (3) with anti-canalicular autoantibodies. Apoptotic cells of the foveolar and of the glandular epithelium in the antrum and corpus were counted. The number of apoptotic cells in the gastric mucosa was significantly increased in all cases of gastritis. The highest number of apoptotic cells was observed in the gastric glands of the corpus mucosa in Helicobacter pylori gastritis with anti-canalicular autoantibodies. Apoptosis contributes to the development of gastric atrophy and there are various types of Helicobacter pylori gastritis. The positive correlation between apoptotic cell loss in the glandular zone of the corpus mucosa and the presence of anti-canalicular autoantibodies indicates a possible link between antigastric autoimmunity and atrophy in this type of Helicobacter pylori gastritis – similar to that in classic type A gastritis. Received: 19 November 1997 / Accepted: 24 March 1998     

Helicobacter felis gastritis in gnotobiotic rats: an animal model of Helicobacter pylori gastritis.

The gastric spirillum Helicobacter felis, originally isolated from the cat stomach, colonizes the stomachs of germfree rats. Studies were designed to examine the pathological and serological responses of germfree rats inoculated orally with H. felis. At 2 weeks postinoculation, the gastric mucosa of germfree rats had lymphocytes and eosinophils scattered in small foci throughout the subglandular region of the antrum. Small numbers of lymphocytes were present in the subglandular portion of the antral mucosa that focally extended through the lamina propria towards the luminal surface. Eight weeks postinoculation, the inflammation was confined to the antrum. It was characterized by increased numbers of lymphocytes and eosinophils in the subglandular areas, with focal aggregates of lymphocytes in the submucosa. Some lymphoid aggregates extended from the submucosa through the muscularis mucosa and lamina propria to the luminal surface. H. felis was demonstrated with the Warthin-Starry stain, bacterial culture, and urease assay, particularly in the antrum. H. felis also produced a significant immunoglobulin G antibody titer at 2, 4, and 8 weeks postinoculation as well as a transitory immunoglobulin M response at 2 to 4 weeks postinoculation. Contact control rats were not infected, inferring that fecal-oral spread of H. felis did not occur.     

Some ultrastructural aspects of Helicobacter pylori gastritis.

Ultrastructural examinations of biopsy specimens of the gastric mucosa were performed in 20 patients with chronic gastritis proven by endoscopy and microscopy. The presence of the Helicobacter pylori bacteria was found in close contact with epithelial cells of the antrum and corpus of the stomach. The bacteria were not present in the areas of frequently observed intestinal metaplasia. There were ultrastructural changes on the surface and within the cytoplasm of the epithelial mucous cells, which indicated their disturbed metabolism.     

Antigastric autoantibodies in Helicobacter pylori gastritis: prevalence, in-situ binding sites and clues for clinical relevance

Colonization of human gastric mucosa with Helicobacter pylori leads to chronic active gastritis and induces the occurrence of an acquired mucosa-associated lymphoid tissue (MALT) in the stomach. This remodelling of the gastric mucosa together with chronic antigen persistence may induce autoimmune reactions. The aim of this study was to investigate humoral autoimmune reactions to human gastric mucosa in H. pylori gastritis and their clinical relevance. Sera from patients with dyspeptic symptoms were tested for presence of IgG immunoglobulins against H. pylori. Gastric infection with H. pylori and alterations of gastric mucosa were demonstrated by histological examination of gastric biopsy specimens. All sera were tested for reactivity against human gastric mucosa by immunohistochemistry. Two different in-situ binding sites of antigastric autoantibodies were observed. Binding to canalicular structures within parietal cells was significantly correlated with antibodies to H. pylori, elevated basal gastrin levels and atrophy of gastric corpus glands. Our data indicate that autoimmune reactions to antigens in the human gastric mucosa occur in H. pylori gastritis and that they may play a role in the pathogenesis of the disease.     

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.     

Evidence for ethnic tropism of Helicobacter pylori.

Helicobacter pylori infection in humans is linked to gastritis, gastric and duodenal ulcers, and gastric cancer. Peptic ulcer disease, as distinct from chronic asymptomatic infection, is strongly associated with expression of bacterial virulence markers, including a major antigen, CagA, and the vacuolating cytotoxin VacA. We have previously described significant differences in colonization rates, independent of socioeconomic status, among ethnic groups in New Zealand. To evaluate relative risks for peptic ulcer disease, we examined the frequency of two virulence markers in H. pylori strains infecting these ethnic groups. Although these markers occurred significantly more frequently in strains isolated from Polynesians than in strains from Europeans, this frequency was not reflected in the incidence of peptic ulcer disease in the two groups. DNA fingerprinting of the urease gene showed that Polynesians are more frequently infected by a group of strains which are genetically distinct from those affecting European New Zealanders. Our data suggest that separate bacterial lineages may have evolved in parallel with race-specific specialization.     

Experimental gastritis induced by Helicobacter pylori in Japanese monkeys.

We used Japanese monkeys (Macaca fuscata) to establish an experimental model in order to clarify the pathogenicity of Helicobacter pylori in gastric and duodenal disorders. A suspension (5 ml; 10(9) CFU/ml) of H. pylori cells isolated from humans was sprayed around the antrum of the stomach of each of 12 of 17 animals with an endoscope. The remaining five animals were not inoculated; they served as a control group. On days 7, 14, and 28 after inoculation, the gastric mucosa samples were examined grossly and were biopsied for microscopic examination with an endoscope. H. pylori was recovered from 7 of the 12 inoculated animals (58%), and infiltration by neutrophils and monocytes was observed histologically. Macroscopic gastritis with erythema and erosions were noted for five of these animals. On day 28 after inoculation, five animals in the infected group were treated with ampicillin. In two infected but untreated animals, the bacteria persisted for more than 6 months. The result of the gastritis scoring of the antral mucosa and the ammonia concentration in the gastric secretion were significantly higher (P < 0.01 to 0.001) for the infected group than for the control group; however, these values decreased to levels comparable to those for the control group after treatment with ampicillin. Urease activity was positive in gastric biopsy specimens from five of the seven animals in the infected group after 7 days and from four of these animals after 14 days but was negative in all specimens from animals in the control group. The level of antibody (immunoglobulin G) in serum for the infected group was elevated but changed very little for the control group. These results suggest that this M. fuscata model can be used to study H. pylori infection and that H. pylori can induce gastritis.     

Helicobacter pylori infection and chronic gastritis in gastric cancer.

AIMS: To investigate the prevalence of Helicobacter pylori associated chronic gastritis in patients with gastric cancer. METHODS: Serum IgG antibodies for H pylori were determined in 54 consecutive patients with gastric carcinoma. The prevalence of H pylori in gastric mucosa was also examined histologically (modified Giemsa) in 32 patients from whom adequate biopsy specimens of the antrum and corpus were available. Thirty five patients with gastrointestinal tumours outside the stomach and 48 with non-gastrointestinal malignancies served as controls. RESULTS: Of the 54 patients, 38 (70%) had H pylori antibodies (IgG) in their serum (three additional patients had H pylori antibodies IgA, class specific but not IgG specific). This prevalence was significantly higher (p less than 0.05) than that (49%) in the 35 controls. No differences in prevalence of H pylori antibodies were found between gastric cancer cases of intestinal (IGCA) or diffuse (DGCA) type, both these types showing H pylori antibodies (IgG) in 71% of the patients. In the subgroup of 32 subjects, five patients had normal gastric mucosa and four showed corpus limited atrophy ("pernicious anaemia type" atrophy of type A). All of these nine patients had no evidence of current or previous H pylori infection in serum (no IgG antibodies) or in tissue sections (negative Giemsa staining). The remaining 23 patients had antral or pangastritis, and all had evidence of current or previous H pylori infection. CONCLUSIONS: H pylori associated chronic gastritis was the associated disease in 75% of the patients with gastric cancer occurring equally often in both IGCA and DGCA groups. About 25% of cases seem to have a normal stomach or severe corpus limited atrophy, neither of which showed evidence of concomitant H pylori infection.     

Helicobacter pylori gastritis and primary gastric non-Hodgkin's lymphomas.

AIMS--To evaluate further the relation between gastric malignant lymphoma of the mucosa associated lymphoid tissue (MALT) and Helicobacter pylori. METHODS--One hundred and sixty two surgical specimens of MALT lymphoma were retrospectively investigated to determine tumour type and inflammatory patterns. In 121 cases biopsy specimens obtained before surgery were available and stained with haematoxylin and eosin, periodic acid Schiff, Giemsa and Warthin-Starry stains. RESULTS--Residual lymphoid follicles were found less often in high grade malignant than in low grade malignant MALT lymphomas. Chronic active gastritis was shown within the mucosa at some distance from the tumours in 143 of 146 specimens. In all the cases for which biopsy specimens could be evaluated, colonisation of the mucosa by H pylori had occurred. Lymphoid follicles and lymphoid aggregates were detected in 82.7% of the antral, and in 85% of the body mucosa specimens. CONCLUSIONS--These data support the hypothesis that H pylori has an important role in the development of MALT lymphomas. Furthermore, the chronic inflammation preceding malignant transformation might enhance the probability of malignant transformation via chronic stimulation of the lymphoid tissue. This might in part indicate why MALT lymphomas occur most often in the stomach.     

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.     

Helicobacter pylori, gastritis, and peptic ulceration in the elderly.

AIMS: To determine the histopathological types of gastritis, presence of H pylori, and of peptic ulceration in patients aged 70 and over, compared with younger adults. METHODS: Gastric antral and corpus biopsy specimens from 112 elderly patients were classified and graded histologically according to the Sydney system. Details of recent antibiotic and non-steroidal anti-inflammatory drug use were recorded. Eighty four of the patients were positive for H pylori IgG antibodies and parietal cell antibodies. The results were compared with those from a series of 124 adult patients aged under 60. RESULTS: H pylori were visible at histological examination in only 57 of 87 (65.5%) elderly patients with chronic gastritis (excluding "special forms") compared with 72 of 79 (91.1%) of the younger patients with gastritis (p < 0.0002). Severe atrophy of the corpus mucosa was significantly associated with absence of H pylori (p < 0.002), and was present in eight of 30 elderly patients with helicobacter negative gastritis. Other explanations for absence of H pylori include recent antibiotic intake, more intestinal metaplasia, and lower bacterial load in elderly patients (p < 0.05). Autoimmune gastritis and NSAID use did not seem to be relevant. Serodiagnosis showed reduced sensitivity (81%) in patients who were helicobacter positive histologically, but was positive in 14 of 23 (61%) with H pylori negative gastritis histologically, suggesting either current infection that had been missed or previous infection. Peptic ulceration was significantly associated with NSAID use, but not with H pylori in the elderly. CONCLUSIONS: The spectrum of gastritis is different in the elderly, compared with younger adults, due to a significant group with chronic gastritis who are H pylori negative on histological examination. NSAID use, but not demonstration of H pylori (at histological examination) is associated with peptic ulceration in the elderly.     

Association of Helicobacter pylori with HLA-DR antigen expression in gastritis.

AIMS: To assess the association between Helicobacter pylori-associated gastritis and HLA-DR antigen (class II antigen) expression. METHODS: Fifty endoscopic gastric biopsy specimens were studied for the presence of H pylori, degree and type of inflammation, and for HLA-DR antigen expression in the epithelium. The cases were chosen to represent different categories: inflamed gastric mucosa with (n = 13) and without (n = 20) H pylori, and non-inflamed mucosa (n = 17). RESULTS: The antigen was aberrantly expressed in the antral mucosal epithelium in 11 of 12 cases (92%) with acute-on-chronic gastritis when H pylori was also present. It was present in the antrum in only seven of 18 H pylori negative cases (39%) with acute-on-chronic/chronic gastritis. One of three cases of acute gastritis and three of seven cases of chronic gastric erosions (non-inflamed category) showed positive staining. Generally, there was more staining in the antral than body mucosa and in the surface/foveolar epithelium than in the glands. No aberrant HLA-DR antigen expression was found in the 10 cases of normal gastric mucosa examined. CONCLUSIONS: These findings suggest that H pylori may have a role in the induction of class II HLA antigen expression in chronic gastritis and lend support to the view that these organisms may be responsible for part of the inflammatory response.     

Mast cells in Helicobacter pylori associated antral gastritis

Mast cells are known to be effector cells in various inflammatory reactions, but their role in gastritis is unclear. The present study was undertaken to investigate the extent of mast cell involvement in antral gastritis with and without Helicobacter pylori (H. pylori) infection and thus evaluate the possible role of mast cells in the pathogenesis of H. pylori-associated gastritis. Antral mucosal biopsies were taken from 212 subjects with symptoms suggestive of acid peptic disease. Sections were assessed for inflammation. Modified Giemsa stain was used to detect H. pylori infection and 1% toluidine blue to count mast cells. Mast cell counts were significantly higher in the antral mucosa even in H. pylori-negative gastritis (68.4 +/- 6.7/mm2), as compared to normal non-inflamed mucosa (45.7 +/- 5.8/mm2) (P < 0.05). However, with H. pylori infection, the mucosal mast cell count were markedly increased (123.8 +/- 4.7/mm2) as compared to normal mucosa (P < 0.01). and H. pylori-negative gastritis (P < 0.01) this increase was noticed uniformly in patients with H. pylori-positivity, irrespective of the presence or absence of a peptic ulcer. After cure of H. pylori infection, the mast cell density decreased significantly (44.9 +/- 4.6/mm2) to reach levels that were similar to those in normal mucosa. There was a positive correlation between the antral mucosal mast cell density and polymorphonuclear and mononuclear cell infiltration (rs = 0.61). H. pylori infection, and 0.73 respy. It was concluded that could be responsible for increasing the mast cell density in the gastric antrum. Probably by inducing castain mucosal cytokine.     

Chemical gastritis induced by naproxen in the absence of Helicobacter pylori infection.

AIM--To evaluate the histological changes that occur in the antral mucosa of healthy male subjects before and after one week of naproxen administration, using a chemical gastritis score according to the Helicobacter pylori status. METHODS--Nineteen male subjects (mean age 31 years) underwent two endoscopies: one before and the other after one week of naproxen treatment (1 g daily). Antral biopsy specimens were assessed for the presence of H pylori infection and for chemical gastritis, defined as the presence of foveolar hyperplasia, muscle fibres in the lamina propria, oedema, and vasodilatation, in the absence of acute or chronic inflammatory cell infiltrate. RESULTS--Of the 19 subjects, eight had H pylori infection. After one week of naproxen treatment, none of those with H pylori infection developed chemical gastritis, while five of 11 (45%) of those without H pylori infection did. In the absence of H pylori infection there was no evidence of inflammation, either before or after naproxen administration. CONCLUSIONS--A different pattern of antral histological change occurs following naproxen administration. This pattern is related to the presence or absence of H pylori infection, suggesting that H pylori status should be determined in histological studies of subjects taking non-steroidal anti-inflammatory drugs.     

Acute inflammation of the proliferative zone of gastric mucosa in Helicobacter pylori gastritis.

The neutrophilic infiltration has been regarded to represent the activity of Helicobacter pylori gastritis. It may involve the epithelium and/or lamina propria. The incidence and degree of the two types of infiltration do not correlate with each other frequently. We correlated the two types of neutrophilic infiltration with H. pylori infection and other pathologic parameters respectively in 300 randomly selected gastric biopsies as well as serial biopsies from a separate group of 95 patients who were treated for H. pylori infection. The "random biopsies" had chronic gastritis of various degrees, and the organisms were identified in 239 cases (79.7%); in the "treated group," the organisms disappeared completely in 62 cases (65.3%). Characteristically, the intraepithelial neutrophilic infiltration was predominantly localized to the proliferative zone of the gastric mucosa (zone 2) where the density of H. pylori was considerably lower than the surface epithelium. In the "random biopsies," both acute epithelial and interstitial neutrophilic infiltration correlated significantly (p < 0.01) with the H. pylori infection. In the "treated group," however, only acute epithelial inflammation correlated significantly (p < 0.01) with the eradication of infection while acute interstitial inflammation did not. Acute epithelial inflammation was no less frequently present in advanced chronic gastritis than in early chronic gastritis. Acute epithelial inflammation of the proliferative zone is a characteristic pathologic finding of H. pylori gastritis, and appears to be directly associated with the pathogenesis of H. pylori gastritis and its progression.     

Interobserver variation in the histopathological scoring of Helicobacter pylori related gastritis

AIM: To test the reproducibility between two histopathologists of features of Helicobacter pylori gastritis, using the updated Sydney classification. METHODS: 290 dyspeptic Dutch patients with biopsy proven H pylori infection were enrolled in the study. Gastric antral mucosal biopsy specimens were analysed before and after H pylori eradication treatment. The biopsies were scored semi-quantitatively by two histopathologists, according to the updated Sydney classification system. Variables analysed included the density of H pylori infection, the degree of chronic inflammation, inflammatory activity, atrophy, intestinal metaplasia, and surface epithelial damage. Before grading biopsy specimens, both pathologists reached a consensus on the scoring of gastritis through interactive sessions using a multiheaded microscope. Subsequently all biopsy specimens were graded. Interobserver variability was also analysed using weighted kappa scores. RESULTS: For interobserver agreement on scoring the various gastritis features a high degree of reproducibility was reached overall. Agreement on grading of atrophy was the lowest; however, moderate to good reproducibility was achieved, with weighted kappa values of 0.49 in the pretreatment biopsies and 0.52 in the post-treatment biopsies. Disagreement was most common in biopsy specimens with lesser degrees of atrophy. A high degree of agreement was obtained for intestinal metaplasia, with weighted kappa values of 0.72 in the pretreatment biopsies and 0.73 in the post-treatment biopsies. The best agreement was reached in the assessment of the density of H pylori both before and after H pylori eradication treatment, with excellent weighted kappa values of 0.76 and 0.95, respectively. The grade of reproducibility of inflammatory activity, superficial epithelial damage, and chronic inflammation was high, with weighted kappa values varying from 0.60 to 0.76 and 0.62 to 0.83 before and after eradication, respectively. CONCLUSIONS: Reproducibility of grading H pylori related gastritis is high using the updated Sydney system. Despite the novel criteria for scoring atrophy, there was imperfect agreement on this feature between two independent histopathologists.