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Rasmi Y, Sadreddini M, Jamali M, Peirouvi T, Khosravifa F. Frequency of Cytotoxin Associated Gene A(+) Helicobacter pylori in Peptic Ulcer Disease: Difference Between Gastric and Duodenal Ulcer Disease. JOURNAL OF MEDICAL SCIENCES 2009. [DOI: 10.3923/jms.2009.146.150] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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CagA and VacA Helicobacter pylori antibodies in gastric cancer. CANADIAN JOURNAL OF GASTROENTEROLOGY = JOURNAL CANADIEN DE GASTROENTEROLOGIE 2008; 22:255-8. [PMID: 18354754 DOI: 10.1155/2008/521724] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
BACKGROUND Infection with different genotypes of virulent Helicobacter pylori strains (cytotoxin-associated gene A [CagA]- and/or vacuolating cytotoxin A [VacA]-positive) can play a role in the development of atrophic gastritis, duodenal ulcer (DU) and gastric cancer (GC). OBJECTIVE To determine whether patients with GC and H pylori-negative histological staining had previously been infected with H pylori CagA- and/or VacA-positive virulent strains. METHODS Twenty-three GC patients with a mean (+/- SD) age of 68.14+/-9.8 years who tested H pylori-negative on histological staining took part in the study. Three control groups were included. The first group comprised 19 patients with past H pylori infection and DUs eradicated 10 years earlier, with a mean age of 58+/-18.2 years. H pylori-negative status for this group was determined every year with Giemsa staining, and follow-up testing occured 120+/-32 months (mean +/- SD) after therapy. The subsequent control groups included 20 asymptomatic children, with a mean age of 7+/-4.47 years, and with H pylori-negative fecal tests; the final group contained 30 patients without clinical symptoms of H pylori infection, with a mean age of 68+/-11.6 years, who tested H pylori-negative by histological staining. RESULTS Prevalence of CagA and VacA seropositivity, respectively was 82.6% and 73.91% in GC patients; 84.2% and 84.2% in H pylori-negative DU patients; 25% and 5% in H pylori-negative children; and 36.6% and 16.6% in the patients without clinical symptoms on histological staining. CagA and VacA antibody positivity was not significantly different between GC patients and patients with DUs that had been eradicated 10 years earlier. Significant positivity was found between the children's group and the H pylori-negative (with past DUs) group (P<0.001). A statistically significant difference was found in age between groups (P<0.03). CONCLUSIONS Patients with GC, even when H pylori-negative at the time of the present study, may have been infected by H pylori before the onset of the disease, as confirmed by CagA and VacA seropositivity. These data reinforce the hypothesis that H pylori may be a direct carcinogenic agent of GC.
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Abstract
For more than 10 years a vaccine against Helicobacter pylori has been the elusive goal of many investigators. The need for a vaccine was highlighted when eradication attempts in developing countries were foiled by reinfection rates of 15-30% per annum. In addition, physicians in developed countries were concerned that attempts at total eradication of H. pylori would result in widespread macrolide resistance in both H. pylori and other important pathogens. Although attempts to produce vaccines against H. pylori have failed in their ultimate goal, considerable knowledge has been developed on the pathogenesis and immunology of Helicobacter infections. In this article we describe an alternative use for this new knowledge, i.e. a plan to use live Helicobacter species to deliver vaccines against other organisms. Because of its intimate attachment to the gastric mucosa and long-term residence there, H. pylori might succeed as an antigen delivery system, a goal which has eluded most other strategies of nonparenteral vaccination.
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Affiliation(s)
- Barry Marshall
- Helicobacter pylori Research Laboratory, Microbiology and Immunology, University of Western Australia, Perth, Western Australia, Australia.
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Sökücü S, Ozden AT, Süoğlu OD, Elkabes B, Demir F, Cevikbaş U, Gökçe S, Saner G. CagA positivity and its association with gastroduodenal disease in Turkish children undergoing endoscopic investigation. J Gastroenterol 2006; 41:533-9. [PMID: 16868800 DOI: 10.1007/s00535-006-1788-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2005] [Accepted: 02/05/2006] [Indexed: 02/04/2023]
Abstract
BACKGROUND Cytotoxin-associated gene A (CagA) product is a bacterial virulence factor contributing to the pathogenicity of Helicobacter pylori (HP) infection in humans. Host factors, which vary in different countries, interact with bacterial factors to determine the disease state. Our objective was to investigate the frequency of CagA-positive HP strains and evaluate the contribution of CagA positivity to symptoms and development of mucosal lesions in HP-infected Turkish children. METHODS We conducted a prospective clinical trial in 240 consecutive Turkish children undergoing endoscopy (110 girls, 130 boys; mean age, 8.7 +/- 4.3 years). HP infection was diagnosed on the basis of a positive rapid urease test and histology of the mucosal specimens. HP IgG and CagA IgG antibodies were measured by enzyme-linked immunosorbent assay in HP-positive children. RESULTS The HP positivity rate was 50.4% in our study group (51 girls, 70 boys; mean age, 9.9 +/- 3.9 years). CagA was positive in 74.4%. HP infection was less common in children with vomiting (25.9%, P < 0.05). CagA positivity was not associated with any clinical symptom. HP positivity was higher in children with duodenal ulcer (80% vs. 49.1%, P = 0.05); while CagA positivity was similar. Antral nodularity was strongly associated with HP positivity and CagA positivity (30.6% vs. 3.4% and 36.7% vs. 12.9%, respectively, P < 0.05). A negative association between CagA positivity and esophagitis was observed (20% vs. 76.7%, P < 0.05). CONCLUSIONS CagA positivity is common in HP-infected Turkish children. Esophageal lesions are less common in children infected with CagA-positive strains. Although HP is associated with duodenal ulcer disease, CagA positivity does not seem to contribute to development of ulcers in children in our series.
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Affiliation(s)
- Semra Sökücü
- Department of Pediatric Gastroenterology and Hepatology, Istanbul School of Medicine, Istanbul University, Capa, 34390, Istanbul, Turkey
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Sokić-Milutinović A, Todorović V, Milosavljević T. [Clinical significance of infection with cag A and vac A positive Helicobacter pylori strains]. SRP ARK CELOK LEK 2005; 132:458-62. [PMID: 15938230 DOI: 10.2298/sarh0412458s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Clinical relevance of infection with different Helicobacter pylori strains was reviewed in this paper. Helicobacter pylori (H. pylori) infection plays a role in pathogenesis of chronic gastritis, peptic ulcer disease, gastric adenocarcinoma and MALT lymphoma. Extragastric manifestations of H. pylori infection most probably include acne rosacea and chronic urticaria, while the importance of H. pylori infection for pathogenesis of growth retardation in children, iron deficiency anemia, coronary heart disease, stroke and idiopathic thrombocytopenic purpura remains vague. The expression of two H. pylori proteins, cytotoxin associated protein (cag A) and vacuolization cytotoxin (vac A) is considered to be related with pathogenicity of the bacterium. It is clear that presence of cag A+ strains is important for development of peptic ulcer; nevertheless, it is also protective against esophageal reflux disease. On the other hand, cag A+ strains are common in gastric adenocarcinoma and MALT lymphoma patients, but it seems that certain subtypes of vac A cytotoxin are more important risk factors. Infection with cag A+ strains is more common in patients with acne rosacea, stroke and coronary heart disease.
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Zullo A, Sanchez-Mete L, Hassan C, Diana F, Festuccia F, Attili AF, Morini S. Helicobacter pylori density and cagA status in cirrhotic patients: a case-control study. J Gastroenterol Hepatol 2004; 19:1174-8. [PMID: 15377296 DOI: 10.1111/j.1440-1746.2004.03440.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND AND AIM Despite a similar Helicobacter pylori prevalence, peptic ulcer is more frequent in cirrhotic patients than in controls. We evaluated whether cirrhotic patients had an increased bacterial density and/or a higher prevalence of H. pylori cagA-positive strains than controls. METHODS A total of 36 dyspeptic cirrhotic patients with H. pylori infection and 72 matched controls were enrolled. H. pylori infection was detected at histology on Giemsa staining, bacterial density was assessed using difference over baseline (DOB) values at 13C urea breath test, and cagA status was established at serology. RESULTS Overall, both DOB values and prevalence of cagA did not significantly differ between cirrhotic patients and controls. However, peptic ulcer controls showed significantly higher DOB value (27.9 +/- 17.4 vs 19.4 +/- 9.3, respectively; P = 0.009) and cagA positive rate (85%vs 48%; P = 0.01) than non-ulcer dyspepsia patients. Although not statistically significant, a similar trend was observed in cirrhotic patients with peptic ulcer for DOB values (26.5 +/- 16.3 vs 18.3/1000 +/- 9.2, respectively; P = 0.07), whereas the cagA-positive rate was similar between peptic ulcer and non-ulcer dyspepsia patients (60%vs 50%; P = 0.30). CONCLUSIONS The present data showed that both bacterial density and cagA prevalence did not differ between cirrhotic patients and controls.
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Affiliation(s)
- Angelo Zullo
- Gastroenterology and Digestive Endoscopy, Nuovo Regina Margherita Hospital, Rome, Italy.
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Sokic-Milutinovic A, Wex T, Todorovic V, Milosavljevic T, Malfertheiner P. Anti-CagA and anti-VacA antibodies in Helicobacter pylori-infected patients with and without peptic ulcer disease in Serbia and Montenegro. Scand J Gastroenterol 2004; 39:222-6. [PMID: 15074390 DOI: 10.1080/00365520310008403] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND The expression of two Helicobacter pylori proteins, CagA and VacA, is associated with more severe pathogenesis and clinical outcomes of the infection. However, this association varies among geographical regions and ethnic groups. We therefore evaluated CagA and VacA seroprevalence in H. pylori-positive dyspeptic patients in Serbia and Montenegro. METHODS In 173 consecutive dyspeptic patients referred to endoscopy (67M, mean age 49 +/- 15, 76 smokers), immunoblot assay was used to detect serum antibodies against CagA and VacA. Presence of H. pylori infection was assessed using a rapid urease test (RUT), routine histology and serology (anti-IgG ELISA). Duodenal ulcer (DU) was diagnosed in 28, gastric ulcer (GU) in 3 and non-ulcer dyspepsia (NUD) in the remaining 142 patients. RESULTS 129 (74.6%) patients were H. pylori-positive, 27 (96.4%) with DU, 3 (100%) with GU and 99 (69.7%) with NUD (P < 0.01); 121 (93.8%) patients carried anti-CagA antibodies and there was no difference between the DU and NUD groups. VacA antibodies were detected in sera of 50 (38.75%) and were more prevalent in patients with DU compared to the NUD group (P < 0.05). CONCLUSIONS In Serbia and Montenegro there is high seroprevalence of CagA-positive H. pylori strains in dyspeptic patients with and without peptic ulcer, while VacA-positive strains are more closely related to peptic ulcer disease.
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Affiliation(s)
- A Sokic-Milutinovic
- Clinic for Gastroenterology and Hepatology, Institute for Digestive Diseases, Clinical Center of Serbia, University of Belgrade, Serbia and Montenegro.
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Palli D, Menegatti M, Masala G, Ricci C, Saieva C, Holton J, Gatta L, Miglioli M, Vaira D. Helicobacter pylori infection, anti-cagA antibodies and peptic ulcer: a case-control study in Italy. Aliment Pharmacol Ther 2002; 16:1015-20. [PMID: 11966512 DOI: 10.1046/j.1365-2036.2002.01253.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
AIM To evaluate the association between infection with specific strains of Helicobacter pylori and peptic ulcer in patients referred for upper gastrointestinal endoscopy. METHODS One thousand, six hundred and twenty-six consecutive dyspeptic patients, referred to one Endoscopy Unit in Bologna, Italy, were enrolled. For each participant, a blood sample was obtained for the measurement of distinct immunoglobulin G antibodies against H. pylori lysate and cytotoxin associated gene A (cagA). A case-control study included the whole series: patients diagnosed with duodenal (n=275) or gastric (n=71) ulcer were identified and independently compared with controls with non-ulcer dyspepsia (n=1280). RESULTS H. pylori seroprevalence (at least one positive marker) was associated with increasing age, male sex and a diagnosis of peptic ulcer. This association was stronger with duodenal ulcer (multivariate odds ratio (OR), 5.2; 95% confidence interval (CI), 3.5-7.9) than with gastric ulcer (OR, 2.3; 95% CI, 1.2-4.4). Further analyses showed that H. pylori lysate+/cagA- subjects had a moderately increased risk of duodenal (OR, 3.2), but not gastric (OR, 1.1), ulcer. When cagA+ subjects were separately compared with seronegative patients, there was a six-fold increased risk for duodenal ulcer and a three-fold increased risk for gastric ulcer. CONCLUSIONS A strong positive association between infection with a cagA+ H. pylori strain and the presence of peptic disease was found. The seroprevalence of anti-cagA antibodies among patients with non-ulcer dyspepsia is so high (41%) to preclude its use as a pre-endoscopic screening test.
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Affiliation(s)
- D Palli
- Epidemiology Unit, CSPO, Florence, Italy
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Paoluzi OA, Rossi P, Montesano C, Bernardi S, Carnieri E, Marchione OP, Nardi F, Iacopini F, Pica R, Paoluzi P. Discrepancy between polymerase chain reaction assay and Western blot analysis in the assessment of CagA status in dyspeptic patients. Helicobacter 2001; 6:130-5. [PMID: 11422468 DOI: 10.1046/j.1523-5378.2001.00019.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
BACKGROUND Infection with CagA-positive Helicobacter pylori may be diagnosed by detecting cagA gene by polymerase chain reaction assay (PCR) or serum antibodies against CagA by Western blot analysis. The aim of this study is to evaluate whether results of PCR and Western blot analysis are in agreement in CagA status assessment. PATIENTS AND METHODS Thirty-six dyspeptic patients with unknown H. pylori status underwent upper gastrointestinal endoscopy to assess the presence of mucosal lesions and to collect six gastric biopsies (three from the antrum and three from the body) for evaluation of H. pylori infection (rapid urease test, histology and PCR for ureA gene) and gastritis. CagA status was assessed by PCR (cagA gene) on two biopsy specimens and by Western blot analysis of serum (CagA-antibodies) in each patient. RESULTS At endoscopy, nine patients showed normal mucosa, 15 a duodenal ulcer and 12 antral erosions. Twenty-eight patients were found to be H. pylori-positive and eight H. pylori-negative. Of the 28 H. pylori-positive patients, 17 were CagA-positive and five were CagA-negative by both methods, five were CagA-positive by Western blot analysis but not by PCR and one was CagA-positive by PCR but not by Western blot analysis. Of the eight H. pylori-negative patients, none was CagA-positive by PCR, while six were CagA-positive by Western blot analysis. Therefore, the two tests agreed in only 24 patients (67%). In those patients in whom the PCR and Western blot analysis were not in agreement, the histological features appear to suggest that the results of the Western blot analysis should be considered false positives or false negatives. CONCLUSIONS PCR and Western blot analysis failed to provide comparable data in many cases. Western blot analysis seems to be more likely to give misleading results than PCR. Thus, PCR seems to be the method of choice to assess CagA status.
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Affiliation(s)
- O A Paoluzi
- Department of Microbiology, University of Tor Vergata, Italy
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Orsini B, Ciancio G, Censini S, Surrenti E, Pellegrini G, Milani S, Herbst H, Amorosi A, Surrenti C. Helicobacter pylori cag pathogenicity island is associated with enhanced interleukin-8 expression in human gastric mucosa. Dig Liver Dis 2000; 32:458-67. [PMID: 11057919 DOI: 10.1016/s1590-8658(00)80001-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND In vitro studies showed that Helicobacter pylori strains carrying the cag pathogenicity island are able to induce epithelial secretion of Interleukin-8. AIMS To evaluate the assessment of cag pathogenicity island and the expression of Interleukin-8 in the gastric mucosa of Helicobacter pylori-infected patients and correlate these data with the activity of gastritis and Helicobacter pylori density. METHODS cag status was determined by polymerase chain reaction directly on gastric biopsies from 13 Helicobacter pylori+ patients with non-ulcer dyspepsia and 13 Helicobacter pylori+ with duodenal ulcer. Interleukin-8 gene transcription and protein expression were analysed by in situ hybridization and immunofluorescence, respectively. Gastritis activity and Helicobacter pylori density were also investigated. RESULTS cag was present in 20/26 of Helicobacter pylori+ patients: in 7/13 non-ulcer dyspepsia (53.8%] and in 13/13 duodenal ulcer patients (100%), (p<0.05). Interleukin-8 mRNA and protein expression in epithelial and inflammatory cells was higher in cag+ than in cag- patients (p<0.005). Gastritis activity significantly correlated with cag (p<0.05) and Interleukin-8 expression (p<0.005]. Helicobacter pylori density was enhanced in cag+ [p<0.005] and correlated with Interleukin-8 expression (p<0.0051. CONCLUSIONS The present study demonstrates that in Helicobacter pylori-infected human gastric mucosa, cag+ infection is associated with enhanced Interleukin-8 expression, higher levels of active gastritis and bacterial density, and presence of duodenal ulcer.
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Affiliation(s)
- B Orsini
- Department of Clinical Pathophysiology, University of Florence, Italy
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Fallone CA, Barkun AN, Göttke MU, Best LM, Loo VG, Veldhuyzen van Zanten S, Nguyen T, Lowe A, Fainsilber T, Kouri K, Beech R. Association of Helicobacter pylori genotype with gastroesophageal reflux disease and other upper gastrointestinal diseases. Am J Gastroenterol 2000; 95:659-69. [PMID: 10710054 DOI: 10.1111/j.1572-0241.2000.01970.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Helicobacter pylori (H. pylori) is a recognized pathogen, but it may also have a protective effect for gastroesophageal reflux disease (GERD). We compared the prevalence of potential virulence factors (cagA, cagE, vacA genotypes) in GERD to other upper gastrointestinal diseases and controls. METHODS A total of 405 patients underwent gastroscopy with H. pylori isolation and serum testing. Patient diagnostic subgroups were prospectively defined. Genotypes were determined by amplification using polymerase chain reaction. CagA antibodies were determined by western blot, enzyme-linked immunosorbent, and flow microsphere immunofluorescent assays. RESULTS Patients were grouped as follows: nonulcer dyspepsia (26%), GERD (20%), gastric ulcer (17%), duodenal ulcer (12%), gastric cancer (6%), or controls (19%). The cagA gene was present in 94-97% of subjects in all categories, but the cagA antibody was less prevalent in nonulcer dyspepsia (69%, 95% CI: 48-86%, p = 0.02) and GERD (69%, CI: 39-91%, p < 0.05) than in those with gastroduodenal pathology including gastric ulcer, duodenal ulcer, and gastric cancer (92%, CI: 81-98%). The cagE gene and vacA S1 genotype were more frequent in patients with gastroduodenal pathology (p < 0.01). GERD was associated with a significantly lower rate of vacA S1 genotype than controls (29% (CI: 10-56%) versus 80% (CI: 59-93%), p < 0.01). The vacA S1 genotype was associated with the presence of cagA antibodies. CONCLUSIONS The cagE and vacA S1 genotypes are more prevalent in patients with peptic ulcer or gastric cancer, suggesting a potential function in virulence for these genes. However, the vacA S1 genotype was also more prevalent in controls than GERD, suggesting a potential protective effect against GERD.
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Affiliation(s)
- C A Fallone
- Division of Gastroenterology, McGill University Health Center, McGill University, Montreal, Quebec, Canada
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Maaroos HI, Vorobjova T, Sipponen P, Tammur R, Uibo R, Wadström T, Keevallik R, Villako K. An 18-year follow-up study of chronic gastritis and Helicobacter pylori association of CagA positivity with development of atrophy and activity of gastritis. Scand J Gastroenterol 1999; 34:864-9. [PMID: 10522603 DOI: 10.1080/003655299750025318] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND We wanted to evaluate the course of chronic gastritis and its association with Helicobacter pylori and CagA seropositivity in an adult sample from Saaremaa (Estonia) during an 18-year follow-up. METHODS Seventy persons (31 men, 39 women; median age, 57.5 years) from a primary sample of 304 subjects endoscoped in 1979 were reinvestigated by endoscopy and biopsy in 1997. The state of the gastric mucosa and the presence of H. pylori in histologic sections from the antrum and corpus were assessed both in 1979 and 1997 in 66 subjects in accordance with the Sydney system, and H. pylori status in all 70 subjects was determined with the enzyme-linked immunosorbent assay (ELISA). Anti-CagA IgGs were determined with the ELISA, using the recombinant fragment of CagA. RESULTS During an 18-year follow-up 11% of the subjects developed atrophy in the antrum, whereas 35% developed it in the corpus. Development of atrophy in the corpus and the appearance of intestinal metaplasia in the antrum were associated with increased activity of gastritis both in the initial and last follow-up biopsies. Anti-CagA positivity was found in 71% of H. pylori-seropositive persons (94% of subjects). There was a significant association between CagA positivity and the activity of gastritis, the presence of atrophy or damage to surface epithelial cells in the antrum and in corpus mucosal biopsy specimens at the last follow-up endoscopy. CONCLUSION The CagA-positive strains of H. pylori enhance the development of atrophic gastritis compared with CagA-negative strains.
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Affiliation(s)
- H I Maaroos
- Dept of Family Medicine, Hospital of Oncology, University of Tartu, Estonia
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Abstract
Intensive investigation into the interactions of Helicobacter pylori with the human host during the period of this review has led to several important developments in our understanding of H. pylori pathogenesis. There is direct evidence to support a central role for bacterial adhesion to host gastric epithelial Lewis antigens. Adherence can result in activation of host signaling cascades, including tyrosine phosphorylation events. H. pylori induces an immune response that is skewed toward a T-helper cell (Th) 1 phenotype, and an insufficient Th2 response is associated with the inability of the host to eradicate the organism. An area of active investigation has been the induction of epithelial apoptosis, both in direct response to H. pylori and by T-cell mediated pathways. Although the consensus is that the cagA gene product is not involved in pathogenesis, the presence of the cag pathogenicity island is associated with increased gastric inflammation and decreased epithelial repair. Interestingly, infection with cagA+H. pylori appears to result in decreased prevalence of both gastroesophageal reflux disease and adenocarcinoma of the esophagus and cardia.
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Affiliation(s)
- K T Wilson
- Division of Gastroenterology, Department of Medicine, University of Maryland School of Medicine and Baltimore Veterans Affairs Medical Center, University of Maryland Medical Systems, Room N3W62, 22 South Greene Street, Baltimore, MD 21201, USA
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