Translocation t(11;18)(q21;q21) in gastric B-cell lymphomas.

Translocation t(11;18)(q21;q21) is the most frequent chromosomal aberration reported in gastric mucosa-associated lymphoid tissue (MALT) lymphomas. Intriguingly, this translocation has been reported only rarely in diffuse large B-cell lymphomas; it has been proposed that t(11;18)-positive tumors rarely progress to diffuse large B-cell lymphomas. We examined the frequency of chromosomal translocation t(11;18)(q21;q21) in mucosa-associated lymphoid tissue lymphoma and diffuse large B-cell lymphoma of the stomach. Paraffin-embedded tissues from patients with gastric B-cell lymphomas were selected retrospectively. The presence of the t(11;18)(q21;q21) was determined using reverse transcriptase-polymerase chain reaction and/or fluorescence in situ hybridization. beta-Actin transcript was also determined to evaluate the integrity and efficiency of RNA (cDNA) recovery from paraffin-embedded tissues. We analyzed 53 gastric B-cell lymphomas (33 diffuse large B-cell and 20 mucosa-associated lymphoid tissue) obtained from Italy, the USA, or Japan. Beta-actin transcript was amplified in 50 cases (94%), including 19 mucosa-associated lymphoid tissue and 31 diffuse large B-cell lymphomas (five with mucosa-associated lymphoid tissue components). The t(11;18) translocation was detected in 19% (6 of 31) cases with diffuse large B-cell lymphoma versus 26% (five of 19) with mucosa-associated lymphoid tissue lymphoma (P = 0.72). One of five diffuse large B-cell lymphomas with a mucosa-associated lymphoid tissue component showed the t(11;18)(q21;q21). In conclusion, translocation t(11;18)(q21;q21) was found in both mucosa-associated lymphoid tissue lymphomas and diffuse large B-cell lymphomas of the stomach at approximately equivalent frequencies; its presence does not exclude progression to diffuse large B-cell lymphoma.

Mycobacterium avium subspecies paratuberculosis and Crohn's disease granulomas.

OBJECTIVE: Chronic infection with Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) has been proposed as a cause of Crohn's disease. Although numerous investigators have examined the link between M. paratuberculosis and Crohn's disease, the evidence remains controversial. The aim of this study was to examine intestinal granuloma from Crohn's patients for M. paratuberculosis using a semi-nested M. paratuberculosis-specific IS900 polymerase chain reaction (PCR). MATERIAL AND METHODS: Paraffin-embedded ileal or colonic tissues of patients with Crohn's disease were analyzed. Microdissection of this tissue into "granulomas" and "not granulomas" was performed. On the basis of sequences reported in GenBank alignments, we designed primer sets specific for M. paratuberculosis. The presence of the M. paratuberculosis was examined by semi-nested IS900-specific PCR with human beta-actin gene as a control for DNA quality. RESULTS: Biopsies from 20 Crohn's patients were examined. Human beta-actin gene was amplified in all samples. M. paratuberculosis DNA was detected in the microdissected granuloma in 1 (5%) patient with Crohn's disease and in none of the "not granuloma" tissues. CONCLUSIONS: M. paratuberculosis DNA can rarely be detected within Crohn's granuloma. These results do not support M. paratuberculosis as the primary etiology of Crohn's disease.

Gastric atrophy, diagnosing and staging.

H. pylori is now accepted as the cause of gastritis and gastritis-associated diseases, such as duodenal ulcer, gastric ulcer, gastric carcinoma, and gastric MALT lymphoma. The natural history of H. pylori gastritis includes inflammation progressing from the antrum into the adjacent corpus resulting in an atrophic front of advancing injury leading to a reduction in acid secretion and eventual loss of parietal cells and development of atrophy. Sub-typing intestinal metaplasia has no clinical value to the patient, the pathologist, or the endoscopist. The pattern, extent, and severity of atrophy, with or without intestinal metaplasia, is a far more important predictor than is intestinal metaplasia subtype. The challenge remains to identify a reliable marker that relates to pre-malignant potential.

Co-localization of TFF2 with gland mucous cell mucin in gastric mucous cells and in extracellular mucous gel adherent to normal and damaged gastric mucosa.

Trefoil factor 2 (TFF2) is mucin associated peptide that has a mucosal barrier function in addition to participating in repair and healing. We examined the localization of TFF2 and gastric mucins in gastric mucous cells, the surface mucous gel layer (SMGL) adherent to normal gastric mucosa, and in the mucoid cap covering gastric erosions. Carnoy's solution, or formalin/picric acid-fixed paraffin embedded materials from resected stomachs and formalin-fixed paraffin embedded gastric biopsy materials were used. Sections were immunostained for the TFF2 and histochemically stained for gastric mucins. In addition, thick sectioned gastric mucosa fixed in Carnoy's solution were stained with FITC-labeled GSA-II lectin specific for gland mucous cell mucin and examined for three-dimensional images of the SMGL using a confocal laser scanning microscope. The TFF2 and gland mucous cell mucin were found intermixed together in the gastric gland mucous cells, in the SMGL in laminated layers, and in the mucoid cap. A laminated arrangement of continuous sheets of gland mucous cell mucin in the SMGL was demonstrated in the three-dimensional images. Co-localization of the TFF2 with gland mucous cell mucin suggests a physical interaction between the TFF2 and gland mucous cell mucin. The TFF2 trapped in the adherent mucins may be responsible for mucosal defense, healing, and repair.

Noninvasive versus histologic detection of gastric atrophy in a Hispanic population in North America.

BACKGROUND & AIMS: Cancer risk is directly correlated with the severity and extent of mucosal atrophy, making identification of atrophy a goal in cancer prevention programs. The aim of this study was to compare targeted histology with noninvasive testing for the identification of antral and/or corpus atrophy in North America. METHODS: In a cross-sectional study of a random sample of households, 8 gastric biopsy specimens were obtained from defined locations in the antrum and corpus. Biopsies were scored for the presence of Helicobacter pylori and gastric atrophy (defined as loss of normal glandular components). Atrophy was scored by using the Sydney system and a system based on the number and location of corpus biopsies with atrophy. Patients' sera were examined for pepsinogen I, pepsinogen II, and gastrin-17 (fasting and stimulated). RESULTS: One hundred eighty volunteers, approximately 30 per age group and ranging in age from 18-82 years, participated. There were 76 men. The overall weighted prevalence of a corpus atrophy was 4.7% (95% confidence interval, 2.3-7.0). There was a significant inverse relationship between the grade of corpus atrophy and the pepsinogen I/pepsinogen II ratio (R = -0.31, P < .01). We failed to confirm the usefulness of the proposed algorithm by using gastrin-17, H. pylori serology, and serum pepsinogens to categorize the gastric histology. The Sydney system underestimated the prevalence of corpus atrophy by approximately 25%. CONCLUSION: Noninvasive testing is both possible and practical by using pepsinogen assays for the identification of the precancerous condition of moderate to severe corpus atrophy in North American Hispanic patients.

Interobserver variation in the histopathological assessment of malt/malt lymphoma: towards a consensus.

BACKGROUND: The classification of mucosa associated lymphoid tissue (MALT) lymphoma is based on characteristic morphologic and immunophenotypic patterns, with distinctive chromosomal aberrations. The critical first step is diagnosis on evaluating H&E-stained sections. We performed an inter-observer study to determine the degree of agreement among pathologists in evaluating gastric lymphocytic infiltrates for MALT lymphoma. METHODS: A set of 41 H&E-stained gastric sections (36 endoscopic biopsies and 5 surgically resected sections) that ranged from simple gastritis to primary gastric lymphoma was reviewed separately and independently by 17 participants including hematopathologists, pathologists with a special interest in gastrointestinal pathology, and general pathologists. The participants were from the United States, Europe, and Japan. Results were entered into a standardized data collection form and the results were analyzed using kappa statistics. Monte Carlo simulation was used to adjust for multiple biases. RESULTS: Overall, interobserver reproducibility in the morphologic evaluation of gastric MALT was suboptimal. The kappa statistic was 0.3 for simple gastritis, low-grade MALT and for high grade MALT lymphoma. Monte Carlo simulation suggested that the degree of disagreement was directly related to the pathologist's experience in evaluating gastric biopsies for MALT lesions. However, after conjointly reviewing all cases, the Houston workshop agreed on findings that would increase the reproducibility of diagnosis, especially for pathologists with limited experience with this disease. These included the availability of macroscopic data, extensive sampling, the presence of lymphoepithelial lesions, immunophenotyping and particularly abnormal mucosa localization of B-cells, in addition to other molecular finding such as monoclonality and translocation t (11;18). The group also agreed on the need for standardizing the terminology currently used to facilitate future comparison between studies. CONCLUSIONS: Though the study shows poor agreement on morphologic MALT lymphoma categorization, the Houston workshop suggested recommendations that should increase the diagnostic accuracy and reproducibility of MALT lymphoma diagnosis. A follow up workshop will be organized to measure the diagnostic reproducibility for MALT lymphoma using the suggested recommendations.

False negative urea breath tests with H2-receptor antagonists: interactions between Helicobacter pylori density and pH.

BACKGROUND: We studied the effects of famotidine, sodium bicarbonate, and citric acid on the 13C-urea breath test (UBT). METHODS: Helicobacter pylori-infected volunteers received a UBT, 40 mg of famotidine at bedtime, and a second UBT (pudding test meal, 648 mg NaHCO3 tablet then 125 mg of urea in 200 ml of water containing 650 mg of NaHCO3). Experiment 2 consisted of four UBTs. Two were standard citric acid UBTs with 75 mg of urea and 2 g citric acid and two were sequential bicarbonate-citric acid UBTs. Sequential UBTs consisted of administration of a 648 mg bicarbonate tablet with 50 g of Polycose in 200 ml of water. Five minutes later, 125 mg of 13C-urea was given in 75 ml of water containing 650 mg of NaHCO3. Breath samples were collected after 15 minutes. Then, to acutely acidify the stomach, 4 g of citric acid was given in 200 ml of water. A second breath sample was collected 15 minutes after the citric acid. The standard UBTs were done before and after 6 days of famotidine (40 mg b.i.d.). Sequential UBTs were done after 1 and 6 days of famotidine therapy. Gastric biopsies for histology, culture, and mucosal cytokines were assessed before and after 6 days of famotidine. RESULTS: Eighteen subjects participated, 10 in each experiment; seven had endoscopy with biopsy. Famotidine/ bicarbonate resulted an approximately 50% fall in UBT values (p = .021) with 10% becoming negative. The gastric pH increased from 5.1 +/- 0.5 to 6.7 +/- 0.2 (p = .03) although no pH value predicted the occurrence of false negative results. Under famotidine acid suppression, NaHCO3 reduced the delta over baseline (DOB) by 63% (p = .021). This was reversed with citric acid. Histology showed a H2-receptor antagonist-associated increase in the depth of gastric corpus inflammation. CONCLUSIONS: H2-receptor antagonists differ from proton pump inhibitors as high intragastric pH may cause a reduction in urease activity, unrelated to a reduced bacterial load and reversed by citric acid.

Eradication of Helicobacter pylori by 7-day triple-therapy regimens combining pantoprazole with clarithromycin, metronidazole, or amoxicillin in patients with peptic ulcer disease: results of two double-blind, randomized studies.

AIM: To compare the short-term (7-day) safety and efficacy of two triple-therapy regimens using pantoprazole with those of two dual-therapy regimens (one with pantoprazole and one without), for Helicobacter pylori eradication in patients with peptic ulcer disease. METHODS: H. pylori infection was identified by rapid urease (CLOtest), and confirmed by histology and culture. Patients were enrolled into one of two randomized, double-blind, multicenter, parallel-group studies. In study A, patients received oral pantoprazole 40 mg, clarithromycin 500 mg, and metronidazole 500 mg (PCM); pantoprazole, clarithromycin and amoxicillin 1000 mg (PCA); or pantoprazole and clarithromycin (PC). In study B, patients received PCM, PCA, PC, or clarithromycin and metronidazole without pantoprazole (CM). Treatments were given twice daily for 7 days. H. pylori status after therapy was assessed by histology and culture at 4 weeks after completing the course of study treatment. Modified intent-to-treat (MITT; each study: n = 424, n = 512) and per-protocol (PP; each study: n = 371, n = 454) populations were analyzed. The MITT population comprised all patients whose positive H. pylori status was confirmed by culture and histology; the PP population comprised patients who also complied with > or = 85% of study medication doses. RESULTS: A total of 1016 patients were enrolled. Cure rates among patients with clarithromycin-susceptible H. pylori strains were 82 and 86% for PCM, and 72 and 71% for PCA, in studies A and B, respectively. Cure rates among patients with metronidazole-susceptible H. pylori strains were 82 and 87% for PCM, and 71 and 69% for PCA, in studies A and B, respectively. The combined eradication rates observed with the PCM regimen were superior to those of all other regimens tested. Side-effects were infrequent and mild. CONCLUSIONS: PCM had the highest overall eradication rate in these two studies examining 7-day treatment regimens. All regimens were safe and well tolerated.

Enterococcus gastritis.

Helicobacter pylori infection is the most common cause of gastritis with its associated sequelae. Gastritis secondary to other bacteria is rare. This report describes Enterococcus-associated gastritis in a 59-year-old diabetic man. Nine months after receiving treatment for H. pylori-associated gastritis, he underwent endoscopy to confirm H. pylori eradication and to evaluate the status of previously seen ulcers. Mucosal biopsy specimens revealed severe active but focal gastritis adjacent to gram-positive coccobacilli in short to long chains with no H. pylori. Culture grew an Enterococcus similar to E. hirae and E. durans. No treatment was given, and endoscopy done 2 months later showed complete resolution of the gastritis and absence of H. pylori or enterococci. Our patient's gastritis represents a previously undescribed manifestation of Enterococcus infection. It is possible that the presence of NSAID gastric mucosal injury and diabetes predisposed this individual to the development of transient Enterococcus gastritis.

Helicobacter pylori and hetertopic gastric mucosa in the upper esophagus (the inlet patch).

OBJECTIVES: Helicobacter pylori (H. pylori) may colonize gastric mucosa wherever it is found in the GI tract. Heterotopic gastric mucosa in the upper esophagus (inlet patch) is a potential site for H. pylori infection and may provide a reservoir for oral-oral transmission or a niche where antibiotics might have difficulty reaching. The aim of this study was to analyze the intensity and distribution of H. pylori in the inlet patch. METHODS: Whenever a cervical inlet patch was observed, mucosal biopsy samples were taken to confirm the endoscopic diagnosis and to search for H. pylori and active inflammation. In addition, mucosal biopsy samples were also taken from the gastric mucosa. Formalin-fixed biopsy specimens were cut and stained with a new dual stain developed in our laboratory. The stain is a combination of periodic acid-Schiff and a silver stain that allows simultaneous visualization of H. pylori and gastric type epithelium. The density of H. pylori was scored using a visual analog scale of 0 to 5. The type of mucosa in the inlet patch was also recorded. RESULTS: The study included 48 patients; 37 had H. pylori gastritis and 27 of these (73%) had H. pylori identified on their heterotopic gastric mucosa. A higher density of H. pylori in the stomach was associated with a higher prevalence in the inlets. Active inflammation correlated with active infection in the inlet patch and the presence of antral type mucosa. CONCLUSION: H. pylori colonization of heterotopic gastric mucosa in the upper esophagus is common and is closely related to the H. pylori density in the stomach. The fact that H. pylori was not found in all cases suggests that another event such as reflux may be required for H. pylori to colonize heterotopic mucosa.

Studies regarding the mechanism of false negative urea breath tests with proton pump inhibitors.

OBJECTIVE: The mechanism of false negative urea breath tests (UBTs) results among proton pump inhibitor (PPI) users is unknown. We studied the time course of PPI-associated negative UBT, the relation to Helicobacter pylori density, and whether gastric acidification would prevent false negative UBT results. METHOD: In the UBT experiment, H. pylori-infected volunteers received omeprazole 20 mg b.i.d. for 13.5 days. UBTs with citric acid were done before, after 6.5 days of PPI, and 1, 2, 4, 7, and 14 days after therapy. In the culture and histology experiment, after a wash-out of >5 months, nine of the original subjects were rechallenged with omeprazole for 6.5 days. Antral and corpus biopsies for histology and culture were done before and 1 day after PPI administration. RESULTS: Thirty subjects (mean age 42 yr) were enrolled. UBTs were significantly reduced on day 6.5 (p = 0.031); 10 subjects (33%) developed transient negative UBTs. The UBT recovered in all but one subject by the fourth day post-PPI and in all subjects by day 14. In the culture and histology experiment, upon PPI rechallenge, three of nine subjects (33%) had negative UBTs. H. pylori density, whether measured by culture or histology, decreased with PPI therapy; antral biopsies became histologically negative in five subjects and corpus biopsies in three subjects. CONCLUSION: PPI-induced negative UBT results were related to the anti-H. pylori effect of the PPI. Acidification of the stomach did not prevent false negative UBT results. Three days is likely the minimum delay from stopping PPI until one should perform a test for active infection. A delay of 14 days is preferred.

New serological assay for detection of putative Helicobacter pylori virulence factors.

We evaluated a new immunoblot assay (Helicoblot 2.1) for Helicobacter pylori infection and CagA and VacA status by using serum samples from 222 patients. The test accurately detected H. pylori infection and VacA status, but improvements in the interpretation criteria are required before it can be recommended for determination of CagA status.

Genomic fingerprinting and genotyping of Helicobacter pylori strains from patients with duodenal ulcer or gastric cancer from different geographic regions.

Continuing attempts have been made to classify pathogenic strains within bacterial populations based on DNA fingerprints and to identify virulence factors in H. pylori. We studied 287 H. pylori isolates from patients with duodenal ulcer or gastric cancer from three different geographic regions. DNA fingerprints were generated using REP-PCR and analyzed by cluster analysis. The status of three candidate virulence factors-vacA polymorphism, cagA and iceA,-were examined by PCR amplification. Cluster analysis of the REP-PCR fingerprints showed clustering by geographic region but not by disease presentation. cagA was detected in 91.3% of the isolates. Differences in vacA subtypes were observed among the three geographic regions. There was no association between iceA subtypes and clinical outcome. We conclude that geographic differences among the H. pylori strains exist in single gene allelic variants as well as in the conserved noncoding regions such as REP sequences throughout the entire bacterial genome. We did not detect any association between disease presentation and H. pylori genotypes using either DNA fingerprinting or candidate single gene virulence factors.

Clinical presentation in relation to diversity within the Helicobacter pylori cag pathogenicity island.

OBJECTIVE: This study investigated the genetic diversity of the cag pathogenicity island (PAI) in Helicobacter pylori (H. pylori) in relation to clinical outcome and interleukin (IL)-8 production. METHODS: Seven genes in the cag PAI (cagA, cagE, cagG, cagM, cagT, open reading frame 13 and 10) were examined by polymerase chain reaction and Southern blot hybridization using H. pylori from 120 patients with different presentations (duodenal ulcer, gastric cancer, gastritis alone). IL-8 production from AGS cells (gastric cancer cell line) cocultured with H. pylori was measured by ELISA. RESULTS: An intact cag PAI was present in 104 (87%) isolates, and five (4%) had deletions within the cag PAI; 11 (9%) lacked the entire cag PAI. Clinical isolates containing the complete cag PAI induced a greater secretion of IL-8 as compared with those without the cag PAI (3048 +/- 263 vs 480 +/- 28 pg/ml, p < 0.001). Deletion of only cagG reduced IL-8 secretion by two thirds. Deletions of more than one locus reduced IL-8 secretion to background. A similar proportion of H. pylori from patients with gastritis, duodenal ulcer, or gastric cancer had intact cag PAI (88%, 88%, and 85%, respectively). Although the presence of cagG was a better predictor of the presence of an intact cag PAI than cagA or cagE, the presence or absence of any of these genes had no association with clinical presentation. CONCLUSION: Although the cag PAI plays an important role in IL-8 production, clinical presentation cannot be predicted by the presence of an intact cag PAI or any of these seven cag PAI genes.

Importance of Helicobacter pylori oipA in clinical presentation, gastric inflammation, and mucosal interleukin 8 production.

BACKGROUND & AIMS: Disease-associated virulence factors of Helicobacter pylori may not be independent of one another. The aim was to determine which H. pylori virulence factor(s) was the most important predictor of severity of gastric inflammation or clinical outcome. METHODS: cag Pathogenicity island (PAI), vacA babA2, and iceA status were determined by polymerase chain reaction (PCR). oipA functionality was based on switch status determined by PCR-based sequencing. A backward stepwise multiple regression analysis was performed to determine which factor(s) was the most discriminating for clinical outcome as well as the relationship to mucosal histology (H. pylori density, neutrophil infiltration, intestinal metaplasia, and gastric atrophy) and mucosal interleukin 8 (IL-8) production. RESULTS: H. pylori were obtained from 247 patients (86 with gastritis, 86 with duodenal ulcer, and 75 with gastric carcinoma). Although oipA status was closely linked to specific cag PAI, vacA, and babA2 genotypes, only oipA status remained in the final model to discriminate duodenal ulcer from gastritis (adjusted odds ratio [OR] = 5 and 95% confidence interval [CI] = 2.1-11.9). Among the factors, only a functional oipA was significantly associated with high H. pylori density, severe neutrophil infiltration, and high mucosal IL-8 levels (P < 0.001). oipA status had no relationship to gastric atrophic changes. CONCLUSIONS: oipA functional status was related to clinical presentation, H. pylori density, and gastric inflammation. cag PAI, babA2, or vacA status appear important only as surrogate markers for a functional oipA gene.

Patterns of gastric atrophy in intestinal type gastric carcinoma.

BACKGROUND: Multifocal atrophic gastritis (MAG) is currently considered a precancerous lesion leading to intestinal type gastric carcinoma. The current study aimed to describe the topography of atrophy in stomachs with early gastric carcinoma. METHODS: Resected stomachs from patients with intestinal type gastric carcinoma were routinely processed, sectioned (an average of 108 sections/stomach), and stained with a triple stain. Sections were scored on a visual analog scale for Helicobacter pylori and intestinal metaplasia. The type of epithelium (antral, oxyntic, transitional) was recorded. Atrophy was defined as the loss of normal glandular components and included intestinal metaplasia and/or pseudo-pyloric metaplasia of the corpus. Pseudo-pyloric metaplasia was identified by the presence of pepsinogen I in mucosa that was topographically corpus but phenotypically antrum. RESULTS: Sixteen stomachs with intestinal type gastric carcinoma were examined. In none of the specimens examined was MAG (independent foci of atrophy) identified. In the majority (88%), atrophy was present as a continuous sheet. Islands of intestinal metaplasia (multifocal intestinal metaplasia) were present within a sheet of pseudo-pyloric metaplasia. A few specimens (12%) had a non-atrophic corpus with almost total replacement of antral epithelium with intestinal metaplasia. Multifocal dysplasia distant from the original tumor was found both in areas with and without intestinal metaplasia. CONCLUSIONS: Contrary to popular belief, atrophy in intestinal type gastric carcinoma is not present as independent foci, but rather as a continuous sheet. Previous studies failed to identify pseudo-pylori metaplasia as a marker for atrophy.

NSAID gastric ulceration: predictive value of gastric pH, mucosal density of polymorphonuclear leukocytes, or levels of IL-8 or nitrite.

NSAID use and Helicobacter pylori both cause damage to the gastric mucosa and can cause peptic ulcers. Our aim was to test the relationship between gastric mucosal polymorphonuclear leukocyte (PMN) infiltration and the severity of NSAID-induced gastric injury. H. pylori density, mucosal interleukin-8 (IL-8), and nitrite levels were assessed after receiving placebo and again after receiving 1000 mg of naproxen daily for three days. Histology was graded using a visual analog scale (0-5). IL-8 levels were assayed by ELISA and nitrite levels by Griess reaction. Eleven healthy volunteers with H. pylori infection entered. All had normal-appearing gastric mucosa after placebo. Postnaproxen gastric damage included three with none, one with mild, three with moderate, two with severe, and three were very severe mucosal injury (including one with an ulcer >5 mm). There was an inverse correlation between endoscopic score and the pH of the gastric juice post-therapy (R = -0.77, P = 0.004). There was no significant change in histologic or biochemical parameters from pretreatment levels. And none of the parameters (eg, PMN density) predicted endoscopic outcome. In conclusion, there was no relation between mucosal PMN density and endoscopic mucosa injury. PMN infiltration, while not predictive, may be a surrogate for an H. pylori infection-related increased risk of NSAID ulcers.