Role of Th22 cells in Helicobacter pylori-related gastritis and peptic ulcer diseases

Helicobacter pylori (H. pylori) has been shown to be one of the leading causes of peptic ulcer diseases (PUDs) and gastritis. T helper-22 (Th22) cells and its most important cytokine, interleukin-22 (IL-22) are importantly active in inflammation and inflammatory tissues. Since inflammation is one of the main attributes of infection caused by H. pylori and resulting complications (gastritis and gastrointestinal ulcer), this study was designed to evaluate the Th22 cells count and the IL-22 protein expression in people suffering from PUD and gastritis. The present study was conducted on 55 patients with gastritis, 47 patients with PUD and 48 uninfected subjects. After preparation of section and extraction of protein from antral biopsies, immunohistochemistry and western blot methods were used to evaluate the Th22 cells and IL-22 protein expression level, respectively. According to findings, the Th22 cells count and the IL-22 protein expression level in the infected subjects were siginficantly more than in the uninfected subjects. It should be noted that the Th22 cells count and the IL-22 protein expression level in the infected subjects with PUD were significantly greater than those in the infected subjects with gastritis. In addition, the Th22 cells count had positive correlation with the density of H. pylori, chronic inflammation score and acute inflammatory score in the infected subjects with PUD. The Th22 cells count had positive correlation with the Th17 cells count and inverse correlation with the Treg cells count in the infected subjects with PUD and gastritis. Our data demonstrated that abnormal hyper-activation of Th22 cells as well as its correlation with the Th17 cells during infection caused by H. pylori might damage tissues through immunopathological responses.

Regulatory T Cells and Myeloid-Derived Suppressor Cells in Patients with Peptic Ulcer and Gastric Cancer

BACKGROUND

Regulatory T Cells (Tregs) and Myeloid-Derived Suppressor Cells (MDSCs) are two main regulatory cells modulating the immune responses in inflammation and cancer.

OBJECTIVE

To investigate and compare Tregs and MDSCs in peptic ulcer and gastric cancer.

METHODS

Patients with dyspepsia were selected and divided into three groups of non-ulcer dyspepsia (NUD, n=22), peptic ulcer disease (PUD, n=25), and gastric cancer (GC, n=27) according to their endoscopic and histopathological examinations. Helicobacter pylori infection was diagnosed by rapid urease test and histopathology. The number of peripheral blood CD4+CD25+FoxP3+Tregs and CD14+HLA-DR- MDSCs were determined in all patients, by flow cytometry. The number of FoxP3+ regulatory T cells was also determined by immunohistochemistry (IHC).

RESULTS

The percentage of peripheral blood Treg cells in both PUD (0.81 ± 0.39, p<0.001) and GC groups (0.98 ± 0.65, p<0.001) were significantly higher than in NUD group (0.46 ± 0.10). These results were also confirmed by IHC. A significantly higher percentage of MDSCs in patients with PUD (0.73 ± 0.19, p<0.001) and GC (0.73 ± 0.16, p<0.001) was also observed when compared to NUD group (0.46 ± 0.16). There was no difference in the percentages of these two cell types between the PUD and GC groups. The percentages of Tregs and MDSCs in patients with PUD and GC were not significantly correlated.

CONCLUSIONS

Both Tregs and MDSCs showed higher frequencies in PUD and GC. These results suggest that immune-modulation by the Tregs and MDSCs may play a role in the pathogenesis of PUD and GC.

[SYSTEMIC CYTOKINOTHERAPY, USING BETALEUKIN IN A COMPLEX TREATMENT OF AN ACUTE GASTRODUODENAL ULCER BLEEDING]

Results of surgical treatment for an acute ulcer gastroduodenal bleeding in 120 patients, ageing 16-75 yrs old, were analyzed. In 20 of them a gastric ulcer was a cause of bleeding, while in 84--a duodenal ulcer, and in 16--a coexistent gastroduodenal ulcer. The bleeding activity was estimated in accordance to J. Forrest classification. In 57 patients (a comparison group) preoperatively and postoperatively a complex of a standard basal conservative therapy without immunocorrection was conducted, and in 63 (the main group)--a systemic cytokinotherapy (SCKTH), using betaleukin, was applied postoperatively additionally in a complex of therapy. A content of CD3+, CD4+, CD8+, CD19+, IgA, IgM, IgG was estimated in dynamics, as well as circulating immune complexes, phagocytic index, phagocytic number. There was established, that a dysbalance depth in the immune status have had depended upon the blood loss severity. The SCKTH application is pathogenetically substantiated, it promotes the immune status normalization, as well as a more favorable course of postoperative period and the results of treatment improvement.

Frequency of γδ T Cells and Invariant Natural Killer T Cells in Helicobacter Pylori-infected Patients with Peptic Ulcer and Gastric Cancer

To clarify the effect of γδ T cells and invariant Natural Killer T (iNKT) cells in pathophysiology of dyspeptic disorders, number of these two cells in patients with non-ulcer dyspepsia (NUD), peptic ulcer disease (PUD), and gastric cancer (GC) were compared.Patients with dyspepsia were divided into three groups of NUD, PUD, and GC according to their endoscopic and histopathological examinations. Helicobacter pylori infection was diagnosed by rapid urease test and histopathology. The number of peripheral blood CD3+TCRγδ(+) T cells and CD3+Va24Ja18+ iNKT cells were determined by flow cytometry. Immunohistochemistry (IHC) was also used for identifying the TCRγδ+ cells.Forty two patients with NUD (31.6%), 44 with PUD (33.1%), and 47 with GC (35.3%) were included in the study. The frequency of CD3+TCRγδ(+) T cells in peripheral blood of patients with GC (2.71±0.25) was significantly lower than that in NUD (3.97±0.32, p<0.05) and PUD groups (3.87±0.32, p<0.05). However, there was no significant difference in CD3+TCRγδ(+) T cell percentage between the NUD and PUD groups. The frequency of TCRγδ(+) lymphocytes was significantly lower in tissue samples from patients with GC (4.81±0.53) than in NUD (11.09±1.09, p<0.0001) and PUD groups (11.11±1.01, p<0.0001). Also, we could not find any significant difference in the percentage of mucosal TCRγδ+ cells between the NUD and PUD groups. The results showed no significant difference in iNKT cells percentage among the three groups of patients.The results suggest that decreasing number of γδ T cells may be related to development and progression of gastric cancer.

CCL20/CCR6-mediated migration of regulatory T cells to the Helicobacter pylori-infected human gastric mucosa

BACKGROUND

Helicobacter pylori-induced peptic ulceration is less likely to occur in patients with a strong gastric anti-inflammatory regulatory T cell (Treg) response. Migration of Tregs into the gastric mucosa is therefore important.

OBJECTIVE

To identify the homing receptors involved in directing Tregs to the gastric mucosa, and investigate how H pylori stimulates the relevant chemokine responses.

DESIGN

Gastric biopsy samples and peripheral blood were donated by 84 H pylori-infected and 46 uninfected patients. Luminex assays quantified gastric biopsy chemokine concentrations. Flow cytometry was used to characterise homing receptors on CD4(+)CD25(hi) Tregs. H pylori wild-type and isogenic mutants were used to investigate the signalling mechanisms behind CCL20 and IL-8 induction in gastric epithelial cell lines. Transwell assays were used to quantify Treg migration towards chemokines in vitro.

RESULTS

CCL20, CXCL1-3 and IL-8 concentrations were significantly increased in gastric biopsy samples from H pylori-infected patients. CCR6 (CCL20 receptor), CXCR1 and CXCR2 (IL-8 and CXCL1-3 receptors) were expressed by a higher proportion of peripheral blood Tregs in infected patients. Most gastric Tregs expressed these receptors. H pylori induced CCL20 production by gastric epithelial cells via cag pathogenicity island (cagPAI)-dependent NF-κB signalling. Foxp3(+), but not Foxp3(-), CD4 cells from infected mice migrated towards recombinant CCL20 in vitro.

CONCLUSIONS

As well as increasing Treg numbers, H pylori infection induces a change in their characteristics. Expression of CCR6, CXCR1 and CXCR2 probably enables their migration towards CCL20 and IL-8 in the infected gastric mucosa. Such qualitative changes may also explain how H pylori protects against some extragastric inflammatory disorders.

Immune responses to Helicobacter pylori infection

Helicobacter pylori (H. pylori) infection is one of the most common infections in human beings worldwide. H. pylori express lipopolysaccharides and flagellin that do not activate efficiently Toll-like receptors and express dedicated effectors, such as γ-glutamyl transpeptidase, vacuolating cytotoxin (vacA), arginase, that actively induce tolerogenic signals. In this perspective, H. pylori can be considered as a commensal bacteria belonging to the stomach microbiota. However, when present in the stomach, H. pylori reduce the overall diversity of the gastric microbiota and promote gastric inflammation by inducing Nod1-dependent pro-inflammatory program and by activating neutrophils through the production of a neutrophil activating protein. The maintenance of a chronic inflammation in the gastric mucosa and the direct action of virulence factors (vacA and cytotoxin-associated gene A) confer pro-carcinogenic activities to H. pylori. Hence, H. pylori cannot be considered as symbiotic bacteria but rather as part of the pathobiont. The development of a H. pylori vaccine will bring health benefits for individuals infected with antibiotic resistant H. pylori strains and population of underdeveloped countries.

Is there any relationship between Le(b) antigen expression and Helicobacter pylori infection?

INTRODUCTION

Helicobacter pylori infection is one of the main causes of peptic ulcer. There are some blood groups acting as receptors for the pathogen. Based on this view and previous attempts, we tried to examine the relationship between Lewis blood group and H. pylori infection.

MATERIALS AND METHOD

Blood and saliva samples were collected from 60 patients with established peptic ulcer induced by H. pylori. Secretory status of each patient was determined by both direct agglutination and saliva tests.

RESULTS

Seventy-two percent of the patients were secretor and expressed Lewis B antigen. This rate in control group was 61%. Statistical analysis showed no significant difference between the two groups.

CONCLUSION

This study did not find any correlation between Le(b) antigen expression and presence of H. pylori-induced peptic ulcer. It is now recommended that other factors like Lewis(x) and sialyl Lewis(x) should be investigated in binding, colonization and virulence of H. pylori infection in the future.

[Correction of the immunity disorders in patients while surgical treatment of coexistant gastroduodenal ulcers]

There were examined 64 patients, suffering combined gastroduodenal ulcers. Subpopulations of lymphocytes, using monoclonal antibodies, were used to estimate the patients immune status. The investigation was performed in a dynamics: immediately after admittance to hospital, on the operation day and on the tenth postoperative day. In 33 patients (the main group) reamberin was applied in a complex of surgical treatment and in 31 (the comparison group)--the conventional medicinal preparations. In all the patients before the treatment conduction there were revealed the cell immunity chain disorders like in a secondary immune deficiency state (SIDS). The SIDS elimination and the immunological indices improvement were promoted by incorporation of reamberin in the complex of surgical treatment.

[Dynamics of the main immunological indices in patients, suffering gastroduodenal ulcers, complicated by hemorrhage]

A deep clinical, immunological, microbiological analysis was performed in patients, suffering gastroduodenal ulcer, complicated by hemorrhage. Immunodeficiency state with the signs of autoimmunization was noted in the patients. These changes were most severe in a severe blood loss, the local endoscopic hemostasis instability, high risk of the hemorrhage recurrence occurrence, presence in a periulcer zone mucosa of a conditionally pathogenic and pathogenic microflora with a Klebsiella pneumoniae and Streptococcus beta-haemoliticus predominance. The analysis of the data obtained permits to prognosticate the pathologic process severity course and to improve the program of treatment.

[CD25-positivity and efficacy of roncoleukin in complex treatment of patients with gastroduodenal ulcers complicated by hemorrhage]

In 72 patients, suffering gastroduodenal ulcer disease recombinant interleukin-2 (LL-2) Roncoleukin ("Biotech", Russia) was applied in complex of treatment. The main populations of immunocytes, containing cellular-tissue receptor IL-2 CD25, were investigated in specimen from various zones of gastroduodenal mucosa and peripheral blood. There was established the trustworthy hyperexpression of CD25 in patients while gastrointestinal hemorrhage. Roncoleukin inclusion into the complex of treatment of patients have promoted more effective normalization of affinity of various immunocytes type towards IL-2 receptors, clinical signs occurrence of the disease elimination and the ulcer defect epithelization acceleration.

Reduced small-intestinal injury induced by indomethacin in interleukin-17A-deficient mice

BACKGROUND AND AIMS

The pathogenesis of enteropathy induced by non-steroidal anti-inflammatory drugs (NSAIDs) is still unclear, and there are no established treatments. Interleukin-17A (IL-17A) is a pro-inflammatory cytokine that has been associated with the development of chronic inflammatory diseases, including autoimmune diseases. To define the role of IL-17A in small intestinal injury and inflammation, we studied the effects of indomethacin administration in mice with targeted deletions of the IL-17A gene.

METHODS

Male C57BL/6 (wild-type) and homozygous IL-17A(-/-) C57BL/6 mice were subjected to this study. Indomethacin (10 mg/kg) was subcutaneously administered to induce small-intestinal damage. Indomethacin-induced lesions in the small intestine were evaluated by measuring the injured area and by histopathology. Also assessed were myeloperoxidase (MPO) activity, as an index of neutrophil accumulation, and intestinal mRNA expression for inflammatory cytokines.

RESULTS

The area of macroscopic ulcerative lesions, the MPO activity and the mRNA expression of inflammatory-associated chemokines, such as keratinocyte chemoattractant (KC), monocyte chemotactic protein-1 (MCP-1), and granulocyte-colony stimulating factor (G-CSF), were significantly increased in indomethacin-treated groups compared with the sham groups. The development of intestinal lesions by indomethacin was inhibited in IL-17A(-/-) mice compared with wild-type mice, together with significant suppression of the increased levels of MPO activities and KC, MCP-1, and G-CSF levels.

CONCLUSION

These findings demonstrate that IL-17A contributes to the development of indomethacin-induced small intestinal injury through upregulation of G-CSF, KC, and MCP-1. IL-17A might be a promising new therapeutic target to treat NSAID-induced enteritis.

[The level of serum cytokines in children infected with various strains of Helicobacter pylori]

Serum contents of 7 cytokines (IL-1, IL-1beta, IL-6, IL-8, TNF-alpha, INF-gamma, INF-alpha) were examined in 87 children aged 14-17 years according to presence of antibodies against Helicobacter pylori and cytotoxic CagA protein. There was a lack of difference in cytokine levels between infected and non-infected children. Thus H. pylori infection in children in contrast to adults does not cause changes in systemic cytokine secretion.

[Immune polymorphism analysis of HLA class II antigens in ulcer diseases associated with Helicobacter pylori in children]

Previous investigations have linked specific HLA class II alleles DRB1 and DQB1 to H. pylori infection (Y. Huang et al., 2005).

AIM

to investigate potential contribution of HLA-DRB1 and DQB1 alleles in H. pylori infection susceptibility in a Russian pediatric population.

METHODS

Polymerase chain reaction-sequence specific primer (PCR-SSP) method was used to study the HLA-DRB1, DQB1 allelic frequency distribution in 162 children (93 female) with H. pylori infection was determined by culture, breath test and histology.

RESULTS

The carrier frequency of DQB1*03 was higher among H. pylori--positive patients with chronic gastritis only compared with H. pylori-negative patients. The difference in carrier frequencies for HLA-DRB1*17 was higher in H. pylori-positive ulcer patients compared with an uninfected controls (chi2 = 3.69, p = 0.027). In addition, the frequency of genotypes that possess HLA-DQB1*07 allele in the H. pylori-positive children (with peptic ulcer/ chronic gastritis only) was significantly lower than that in the H. pylori-negative control group.

CONCLUSIONS

HLA-DQB1*07 allele may be associated with protection against H. pylori infection independently of clinical outcome. At the same time, HLA-DRB1*17 allele might be associated with susceptible gene to peptic ulcer formation among H. pylori-positive children.

Serum antibodies positivity to 12 Helicobacter pylori virulence antigens in patients with benign or malignant gastroduodenal diseases--cross-sectional study

AIM

To investigate the association of gastric histological and endoscopic findings in patients with Helicobacter pylori (H. pylori), according to presence of seropositivity to 12 bacterial virulence antigens.

METHODS

This is a cross-sectional single-center study of 360 consecutive outpatients referred in the period of one year to upper gastrointestinal endoscopy because of dyspeptic complaints. Patients sera were tested by Western blot method to determine the presence of serum antibodies to bacterial virulence antigens--p120 (CagA--cytotoxin-associated antigen), p95 (VacA - vacuolating cytotoxin), p67 (FSH--flagellar sheath protein), p66 (UreB--urease enzyme heavy subunit), p57 (HSP homologue--heath shock protein homologue), p54 (flagellin), p33, p30 (OMP--outer membrane protein), p29 (UreA--urease enzyme light subunit), p26, p19, and p17. Upper gastrointestinal endoscopy was performed, endoscopic diagnosis recorded, and 4 mucosal biopsy samples were obtained and assessed according to Updated Sydney protocol.

RESULTS

The sera of 207 patients were analyzed. Thirty patients had gastric adenocarcinoma, 126 peptic ulcers, and 51 normal finding. p120 (CagA) seropositivity was significantly more often present in patients with higher activity grade in the antrum (P = 0.025), p30 in patients with greater inflammation in the antrum (P = 0.025) and the corpus (P = 0.010), p33 in patients with greater inflammation in the corpus (P = 0.050), and p19 (OMP) in patients with lower intestinal metaplasia grades in the corpus (P = 0.025). Seroreactivity to all other bacterial proteins showed no association with the histological status of the stomach mucosa. Except for the seropositivity to protein p95 (VacA), which was more often present in patients with duodenal ulcer (P = 0.006), there was no difference in seroreactivity to other bacterial proteins and upper gastrointestinal endoscopic findings.

CONCLUSIONS

p120 (CagA), p33, p30 (OMP), and p19 (OMP) seropositivity was more often present in patients with higher grades of the histological parameters of gastritis and seropositivity to protein p95 (VacA) with endoscopic presence of duodenal ulcer. Histological parameters of gastritis are more associated with bacterial virulence than endoscopic findings.

Isocitrate dehydrogenase of Helicobacter pylori potentially induces humoral immune response in subjects with peptic ulcer disease and gastritis

Background

H. pylori causes gastritis and peptic ulcers and is a risk factor for the development of gastric carcinoma. Many of the proteins such as urease, porins, flagellins and toxins such as lipo-polysaccharides have been identified as potential virulence factors which induce proinflammatory reaction. We report immunogenic potentials of isocitrate dehydrogenase (ICD), an important house keeping protein of H. pylori.

Methodology/Principal Findings

Amino acid sequences of H. pylori ICD were subjected to in silico analysis for regions with predictably high antigenic indexes. Also, computational modelling of the H. pylori ICD as juxtaposed to the E. coli ICD was carried out to determine levels of structure similarity and the availability of surface exposed motifs, if any. The icd gene was cloned, expressed and purified to a very high homogeneity. Humoral response directed against H. pylori ICD was detected through an enzyme linked immunosorbent assay (ELISA) in 82 human subjects comprising of 58 patients with H. pylori associated gastritis or ulcer disease and 24 asymptomatic healthy controls. The H. pylori ICD elicited potentially high humoral immune response and revealed high antibody titers in sera corresponding to endoscopically-confirmed gastritis and ulcer disease subjects. However, urea-breath-test negative healthy control samples and asymptomatic control samples did not reveal any detectable immune responses. The ELISA for proinflammatory cytokine IL-8 did not exhibit any significant proinflammatory activity of ICD.

Conclusions/Significance

ICD of H. pylori is an immunogen which interacts with the host immune system subsequent to a possible autolytic-release and thereby significantly elicits humoral responses in individuals with invasive H. pylori infection. However, ICD could not significantly stimulate IL8 induction in a cultured macrophage cell line (THP1) and therefore, may not be a notable proinflammatory agent.

[Interleukin-1beta gene polymorphism as a predictor of eradication treatment efficacy in gastric and duodenal ulcer associated with Helicobacter pylori]

The results of recent research that IL gene polymorphism powerfully affects the course and the resolve of HP infection and finally impacts its treatment. The present article into the problem of IL polymorphism impact on HP eradication therapy efficiency in ulcer disease. The presence of proinflammatory allele positively influences eradication therapy, which can be used for determining the risk groups and individualized eradication therapy.

[Peculiarities of genotype distribution of interleukins (IL-1 and IL-10) in patients with peptic ulcer disease and their associations with persistence of Mycoplasma hyorhinis and Helicobacter pylori genotypes]

It was found for the first time in our study that there is a significant prevalence of combinations of IL-1 and IL-10 genotypes--IL-1B-511C/C, IL-1B+3954C/C, IL-1RN1/1, IL-10-1082A/A and IL-1B-511T/C, IL-1B+3954C/C, IL-1RN1/2, IL-10- 1082A/G--in the group of patients with gastric and duodenal ulcer disease and control one, respectively. The correlation between the Tox- (cagA- vacAs1-) strains of H. pylori and the combinations of genotypes IL-1B-511T/C, IL-1B +3954C/C, IL-1RN1/1, IL-10-1082G/G was shown (p <0,05). Co-infection with H. pylori and M. hyorhinis was detected in 19% of patients. The association between combinations of genotypes IL-1B-511T/T IL-1B+3954C/C, IL-1RN2/2, IL-10-1082A/G and co-infection with H. pylori and M. hyorhinis was also found (p <0,05).

A low prevalence of H pylori and endoscopic findings in HIV-positive Chinese patients with gastrointestinal symptoms

AIM: To compare the prevalence of H pylori infection, peptic ulcer, cytomegalovirus (CMV) infection and Candida esophagitis in human immunodeficiency virus (HIV)-positive and HIV-negative patients, and evaluate the impact of CD4 lymphocyte on H pylori and opportunistic infections.

METHODS: A total of 151 patients (122 HIV-positive and 29 HIV-negative) with gastrointestinal symptoms were examined by upper endoscopy and biopsy. Samples were assessed to determine the prevalence of H pylori infection, CMV, candida esophagitis and histologic chronic gastritis.

RESULTS: The prevalence of H pylori was less common in HIV-positive patients (22.1%) than in HIV-negative controls (44.8%; P < 0.05), and the prevalence of H pylori displayed a direct correlation with CD4 count stratification in HIV-positive patients. In comparison with HIV-negative group, HIV-positive patients had a lower incidence of peptic ulcer (20.7% vs 4.1%; P < 0.01), but a higher prevalence of chronic atrophy gastritis (6.9% vs 24.6%; P < 0.05)，Candida esophagitis and CMV infection. Unlike HIV-negative group, H pylori infection had a close relationship to chronic active gastritis (P < 0.05). In HIV-positive patients, chronic active gastritis was not significantly different between those with H pylori infection and those without.

CONCLUSION: The lower prevalence of H pylori infection and peptic ulcer in HIV-positive patients with gastrointestinal symptoms suggests a different mechanism of peptic ulcerogenesis and a different role of H pylori infection in chronic active gastritis and peptic ulcer. The pathogen of chronic active gastritis in HIV-positive patients may be different from the general population that is closely related to H pylori infection.

[Effects of cholinergic antagonists in stress]

Effects of methacine, hexamethonium and their combinations with neostigmine on activity of B-lymphocytes in various phases of immune response and development of stress ulcers induced in animals were studied. The drugs were found to modulate B-lymphocyte activity for 28 days and longer. By a water-immersion stress model it was shown that methacin is effective not only as m-cholinolytic but also as an immunoprophylactic drug reducing destructive changes in gastric mucosa. Injection of methacin 30 min before stress (block of m-cholinoreceptors) or 14 days before stress (maximal increase of B cell activity) results in 3-4-fold inhibition of ulcerogenesis in gastric mucosa.

Immunology of Helicobacter pylori infection

Helicobacter pylori is a Gram-negative, spiral bacterium that colonizes the gastric mucosa of at least 50% of the world's population and plays a causative role in the development of chronic gastritis as well as in gastric and duodenal ulcers. H. pylori triggers vigorous humoral and cellular immune responses in both systemic and mucosal compartments. In spite of this response, the vast majority of infected hosts are unable to clear the infection, and it persists for decades. Although Helicobacter is tolerated by a naïve host organism, preclinical studies have demonstrated that prophylactic or therapeutic vaccinations efficiently clear Helicobacter from the stomach. The understanding of the mechanisms leading to the Helicobacter persistence or the vaccine-induced eradication of Helicobacter in animal models will help to define optimal immunization strategies for future anti-Helicobacter vaccination clinical trials.

[Inflammation as a basis for Helicobacter pylori-associated diseases]

The molecular-cellular features of gastric mucosal inflammation caused by Helicobacter pylori are formulated. Chronic gastritis is considered as the morphological basis of gastric ulcer and non-cardial cancer of the stomach of intestinal type. The basic influences of the products of a pathogenicity island of bacterium (Cag A-protein) and VacA-cytotoxin on the gastric mucosa, as well as bacterial genetic polymorphism are discussed. The evolution of the phenotypes of chronic gastritis-- "ulcerative" "cancerous" is analyzed. Helicobacter pylori-associated inflammation may depend on the host's inflammatory response which in turn is determined by the allelic polymorphism of cytokine genes rather than the genetic characteristics of a bacterial strain.

Serum antibody positivity for distinct Helicobacter pylori antigens in benign and malignant gastroduodenal disease

Infection with Helicobacter pylori may be associated with a variety of gastroduodenal diseases. Although H. pylori infection is common, peptic ulcer disease and gastric cancer occur in only a small minority of infected persons. This work was intended to correlate the pathological findings with the serological response to certain H. pylori antigens. Serum samples were taken from 285 patients who underwent gastroscopy. H. pylori infection was diagnosed by histology, culture or rapid urease test (RUT). Serum IgG reactivity against H. pylori-specific antigens was studied by Western blot. There was a significant association between the diagnosis of gastric cancer and the presence of IgG antibodies against the 19.5, 33 and 136 kDa (CagA) antigens. Comparing all H. pylori-positive patients with the gastric cancer group for the presence of the 19.5, 33 and 136 kDa (CagA) antigens, the results were as follows: chi2: 17.482, p < 0.001, power P = 0.994, odds ratio (OR) for the presence of gastric cancer: 19.5 (95% confidence interval (CI): 4.11-92.56). Antibodies against CagA alone or other bands (except 33 and 19.5 kDa antigens), as well as the age of patients were not related to a diagnosis of gastric cancer. Male patients were more likely to develop duodenal ulcer. IgG antibodies against the 19.5, 33 and 136 kDa (CagA) antigens could be helpful to identify patients at enhanced risk for the development of gastric cancer.

Can anti-Helicobacter pylori and anti-CagA antibodies be used to select patients with dyspepsia for gastroscopy?

BACKGROUND

agA IgG antibody in sera may indicate presence of peptic ulcer disease among dyspeptic patients and therefore may be used as a serological marker to identify high risk patients for peptic ulcer who can be subjected to endoscopy. Present study was performed to identify association of CagA IgG antibody in patients with peptic ulcer.

METHODS

Consecutive patients with dyspepsia were subjected to endoscopy and sera was collected from each. Rapid urease test in antral tissue collected from each patient by endoscopic biopsy was performed. Antral tissue was also examined histologically. IgG Antibody against H. Pylori and CagA IgG antibody was tested in each patients sera.

RESULTS

Out of 82 patients with dyspepsia included in the study 28 had peptic ulcer. Of whom 26 were positive for anti IgG H. Pylori antibody. More than 80% patients with peptic ulcer patients had detectable anti Cag A antibody in contrast to 33% patients with non ulcer dyspepsia (P < 0.001).

CONCLUSION

Anti-Cag A antibody may be used as a screening test in patients with dyspepsia to select high risk patients for peptic ulcer for upper gastrointestinal endoscopy.

Pathogenesis of Helicobacter pylori infection

Helicobacter pylori is the first formally recognized bacterial carcinogen and is one of the most successful human pathogens, as over half of the world's population is colonized with this gram-negative bacterium. Unless treated, colonization usually persists lifelong. H. pylori infection represents a key factor in the etiology of various gastrointestinal diseases, ranging from chronic active gastritis without clinical symptoms to peptic ulceration, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue lymphoma. Disease outcome is the result of the complex interplay between the host and the bacterium. Host immune gene polymorphisms and gastric acid secretion largely determine the bacterium's ability to colonize a specific gastric niche. Bacterial virulence factors such as the cytotoxin-associated gene pathogenicity island-encoded protein CagA and the vacuolating cytotoxin VacA aid in this colonization of the gastric mucosa and subsequently seem to modulate the host's immune system. This review focuses on the microbiological, clinical, immunological, and biochemical aspects of the pathogenesis of H. pylori.

Association of Helicobacter pylori IgA antibodies with the risk of peptic ulcer disease and gastric cancer

AIM

To compare the prevalence of Helicobacter pylori (H pylori) IgG and IgA antibodies between adult subjects, with defined gastric diseases, non-defined gastric disorders and those representing the population.

METHODS

Data on H pylori IgG and IgA antibodies, determined by enzyme immunoassay, were analyzed in 3,252 subjects with DGD including 482 patients with gastric ulcer, 882 patients with duodenal ulcer, 1,525 patients with chronic gastritis only and 363 subjects with subsequent gastric cancer, 19,145 patients with NoDg and 4,854 POPUL subjects. The age-adjusted prevalences were calculated for 1- and 20-year age cohorts.

RESULTS

The prevalences of IgG antibodies were equally high (89-96%) in all 20-year age cohorts of the DGD groups, whereas the prevalences of IgG antibodies were lower and increased by age in the POPUL and NoDg groups. The prevalences of IgA antibodies were also higher in the DGD groups; among them CA (84-89%) and GU groups (78-91%) showed significantly higher prevalences than DU (68-77%) and CG patients (59-74%) (OR 2.49, 95%CI 1.86-3.34 between the GU and DU groups). In the CA, GU, and DU groups, the IgA prevalences showed only minor variation according to age, while they increased by age in the CG, POPUL, and NoDg groups (P<=0.0001). The IgA response, but not the IgG response, was associated with an increased risk of CA (OR 2.41, 95%CI 1.79-3.53) and GU (OR 2.57, 95%CI 1.95-3.39) in comparison with CG patients.

CONCLUSION

An IgA antibody response during H pylori infection is significantly more common in CA and GU patients as compared with CG patients.

[Immunoproteomics of Helicobacter pylori--strategy for improvement of diagnostic tests and vaccine development]

Helicobacter pylori, Gram-negative spiral-shaped bacteria, member of epsilon-Proteobacteria, colonizes the gastric mucosa of humans. H. pylori has been identified as the causative agent of chronic inflammation, chronic gastritis and peptic ulceration and is considered a risk factor for the development of mucosa-associated lymphoid tissue lymphoma and adenocarcinoma of the stomach. Although more than 50% of human population is infected with H. pylori only a subset develops disease. The completion of two H. pylori genome sequences revealed the enormous strain heterogeneity and permitted comparative proteome analysis. Immunoproteomics, a novel strategy combining standard proteomics with immunological screening, is currently method of choice for identification of new antigens of diagnostic and protective values. Highly specific antigens will be used as biomarkers of different pathology induced by H. pylori infection whereas novel highly immunogenic, conserved, abundant and surface-located proteins will facilitate efficient anti-Helicobacter vaccine construction.

Natural cytokines: new potentialities of immunotherapy of gastroduodenal ulcer

Addition of splenocytokine therapy to combined therapy of peptic ulcer accelerated healing and prolonged remission.

Helicobacter pylori, T cells and cytokines: the "dangerous liaisons"

Helicobacter pylori infection is the major cause of gastroduodenal pathologies, but only a minority of infected patients develop chronic and life threatening diseases, as peptic ulcer, gastric cancer, B-cell lymphoma, or autoimmune gastritis. The type of host immune response against H. pylori is crucial for the outcome of the infection. A predominant H. pylori-specific Th1 response, characterized by high IFN-gamma, TNF-alpha, and IL-12 production associates with peptic ulcer, whereas combined secretion of both Th1 and Th2 cytokines are present in uncomplicated gastritis. Gastric T cells from MALT lymphoma exhibit abnormal help for autologous B-cell proliferation and reduced perforin- and Fas-Fas ligand-mediated killing of B cells. In H. pylori-infected patients with autoimmune gastritis cytolytic T cells infiltrating the gastric mucosa cross-recognize different epitopes of H. pylori proteins and H+K+ ATPase autoantigen. These data suggest that peptic ulcer can be regarded as a Th1-driven immunopathological response to some H. pylori antigens, whereas deregulated and exhaustive H. pylori-induced T cell-dependent B-cell activation can support the onset of low-grade B-cell lymphoma. Alternatively, H. pylori infection may lead in some individuals to gastric autoimmunity via molecular mimicry.

Helicobacter pylori eradication decreases the expression of glycosylphosphatidylinositol-anchored complement regulators, decay-accelerating factor and homologous restriction factor 20, in human gastric epithelium

BACKGROUND

It has previously been reported that there is a strong correlation between the expression of glycosylphosphatidylinositol (GPI)-anchored complement membrane inhibitor in gastric epithelium and the severity of inflammation of gastric mucosa. To investigate the regulation of complement activity in gastric epithelium during Helicobacter pylori (H. pylori)-associated gastritis, the expression of GPI-anchored complement membrane inhibitors, decay-accelerating factor (DAF) and 20-kDa homologous restriction factor 20 (HRF20), and membrane cofactor protein (MCP), which is a transmembrane protein, were evaluated after removal of the H. pylori stimulus. Furthermore, the expression of the complement fragment, C3c, was also investigated.

METHODS

Forty-six patients with epigastric symptoms and endoscopically confirmed peptic ulcer or gastritis who had H. pylori infection of the gastric mucosa were enrolled in the present study. Biopsy specimens were obtained from the gastric antrum and corpus 1 month before and after eradication. Helicobacter pylori infection was determined by the rapid urease test, histology, and culture before eradication, and by histology, culture, and urea breath test after eradication. Gastric biopsy specimens obtained before and after eradication were evaluated for infiltration by neutrophils and mononuclear cells. The expression of complement membrane inhibitors, DAF, HRF20, and MCP and that of the main complement fragment, C3c, was immunohistochemically evaluated.

RESULTS

One month after the eradication of H. pylori, the infiltration by neutrophils and mononuclear cells in the gastric mucosa decreased significantly (P < 0.0001) as compared with that before eradication. The expression of DAF, HRF20, and C3c on gastric mucosal epithelium also significantly decreased in both the antrum and the corpus (P < 0.05) 1 month after eradication. However, no change was observed in the expression of MCP.

CONCLUSIONS

The decrease in the expression of GPI-anchored complement regulator and the complement after removal of a chronic microbial stimulus suggests that the gastric epithelium appears to undergo an aggressive stress of complement during H. pylori infection. Conclusively, DAF and HRF20 may play an important protective role against complement-mediated damage induced by chronic microbial stimuli in such a pathological condition.

[Gastric cytomedines effects on immune response in acute immobilization stress in rats]

Effects of gastric cytomedines on repair and immune response were studied in 137 white non-inbred rats. Erosions of gastric mucosa were induced by acute immobilization stress. A decrease in antibody production, titers of hemagglutinins and hemolysins was found on day 2 after stress. Gastric cytomedines in a dose 0.15 mg/kg intramuscularly stimulate immune response (increased production of antibodies, antibody dependent cellular cytotoxicity index, titers of hemagglutinins and hemolysins), fast erosions epithelization and have a protective action.

[Helicobacter pylori: focus on CagA and VacA major virulence factors]

After colonizing the human gastric mucosa, Helicobacter pylori can remain within the host for years and even decades, and is associated with several, highly significant gastric pathologies. In Mexico, the seroprevalence at 1 year of age is 20% and the estimated increment in seropositivity per year is 5% for children aged 1-10 years. More than 80% of adults are infected by the time they are 18-20 years old. Bacterial virulence factors have been proposed for H. pylori, such as urease, flagella, heat-shock protein, lipopolysaccharide, adhesions, vacuolating cytotoxin, cag pathogenicity island and the cytotoxin-associated protein, the latter being the most studied mechanism to date.

Increased Frequency of Antral CD4+ T and CD19+ B Cells in Patients with Helicobacter pylori-Related Peptic Ulcer Disease

Only a fraction of Helicobacter pylori (HP)-infected individuals develop clinical disease. Recent research indicates that immunological mechanisms may be important for understanding the pathophysiology of HP infection. Differences in the individual cellular immune response may reflect the clinical diversity. The aim of the present study was to investigate the cellular immune response against HP in three clinically well-defined patient groups: HP-positive peptic ulcer, HP-positive and HP-negative gastritis. Biopsies from gastric mucosa were processed for analysis by flow cytometry and histology. The number of T lymphocytes (CD3+) was significantly higher in HP-positive peptic ulcer (13.8%) than in HP-positive nonulcer gastritis (6.3%). A nonsignificant increase for B lymphocytes (CD19+) was noted as well. Furthermore, a significant difference was seen in mucosal CD4/CD8 ratio between HP ulcer (2.4) and nonulcer HP gastritis (1.0) patients. Thus, B cells (CD19+) and T-helper cells (CD4+) were dominant in gastric mucosa from peptic ulcer patients, and cytotoxic T cells (CD8+) were relatively dominant in gastric mucosa from nonulcer patients. In conclusion, distinct differences in the T-cell subset distribution of mucosal lymphocytes were detected in patients with HP infection, strongly correlated with the presence or absence of peptic ulcer.

[Autoimmune changes in patients with multiple gastroduodenal ulcers and their pathogenetic significance in the complex surgical treatment]

There were examined 73 patients, suffering for multiple gastroduodenal ulcers and included in the main group, and 56 patients with solitary gastroduodenal ulcer, included in the comparison group. The lymphocytes migration impeding reaction (LMIR) was applied to characterize the autoimmune changes in both groups of patients. It was established, that in the patients with multiple gastroduodenal ulcers and with ulcers of small sizes the LMIR was essentially lowered in relation to all the autoantigenes investigated. The data obtained trust the important significance of the immunological investigation conduction in substantiation of the pathologic process pathogenesis, what must be taken into account during performance of surgical treatment and while applying the treatment-rehabilitation measures after the operation.

[Complicated gastroduodenal ulcers]

The results of the treatment of 2384 patients with gastric and duodenal ulcers are analyzed. It is demonstrated that over last years the number of complications has increased: perforations -- 2.6 fold, and bleedings -- 7 fold. Markers of a destructive injury of gastric and duodenal mucosa (helicobacter contamination, immunological disorders, level of tumor necrotic factor alpha, indices of catabolism of connective tissue) were studied. It is revealed that such disorders have direct influence on destruction of gastric and duodenal wall manifesting as life-threatening complications.

[Relationship between CagA-bearing strains of Helicobacter pylori and gastrointestinal pathology]

AIM

To study the prevalence of CagA-positive strains of Helicobacter pylori in Novosibirsk residents and to assess their relation to some clinical parameters.

MATERIAL AND METHODS

Random sample of the population (218 males and 220 females aged 25-64 years) was examined. Antibodies against Helicobacter pylori and CagA protein were tested in the sera using enzyme immunoassay. Gastrointestinal symptoms were evaluated with questionnaire.

RESULTS

The prevalence of H. pylori infection was 88%, among H. pylori-positive persons CagA-positivity was revealed in 58%. Presence of antibodies to CagA protein was associated with dyspepsia (OR = 2.5, 95% CI 1.2-2.5) and history of peptic ulcer (OR = 3.6, 95% CI 1.0-14.5). CagA-positive subjects more frequently reported bowel disturbances, diarrhea, in particular (OR = 2.9, 95% CI 1.2-7.4).

CONCLUSION

The data showed similar distribution of H. pylori and CagA-positivity among adult population in Russia and Eastern European countries. CagA-positivity is associated with peptic ulcer and dyspepsia.

[The value of Helicobacter pylori stool antigen ImmunoCard STAT in diagnosis of HP infection and assessing of eradication of HP]

OBJECTIVE

To evaluate the value of Helicobacter pylori (Hp) stool antigen ImmunoCard STAT (HpSA ImmunoCard STAT) in diagnosis of Hp infection and assessment of eradication of Hp.

METHODS

Stool specimens were collected from 80 patients with upper gastrointestinal symptoms, 41 males and 39 females, aged 18 - 73, 40 of which undergoing gastroscopy and having never received Hp eradicating regimen (group A) and another 40 of which undergoing follow-up examination (group B). HpSA ImmunoCard STAT was used to detect the Hp status in the specimens of stool. Rapid urease test, Hp culture, and Warthin-Starry silver staining were used as "gold standards" to evaluate the Hp status of the biopsy specimens. (13)C-urea breath test ((13)C-UBT) was used as the "gold standard" for the patients that did not undergo gastroscopy. Part of the biopsy specimens of gastric mucosa underwent HpSA test too. The result was considered positive when 2 of the 3 tests in the "gold standard" were positive or culture of Hp was positive.

RESULTS

The sensitivity, specificity, and accuracy of HpSA test for the 80 patients as a whole were 100%, 93.2%, and 96.3%, not significantly different from those of the "gold standard". The sensitivity, specificity, and accuracy of HpSA test for the 40 patients in the group A were 100%, 86.7%, and 95.0% respectively; and the sensitivity, specificity, and accuracy of HpSA test for the 40 patients in the group B were 100%, 96.6%, and 97.5% respectively. The sensitivity and specificity of the 26 gastric biopsy specimens were both 92.3%.

CONCLUSIONS

HpSA test by HpSA ImmunoCard STAT is a simple and accurate test in diagnosis of Hp infection and assessment of eradication of Hp.

Gastrin 17 vaccine--Aphton: Anti-gastrin 17 immunogen, G17DT

Aphton is developing an anti-gastrin vaccine [Anti-gastrin 17 immunogen, G17DT, Gastrimmune], which neutralises the gastrin 17 hormone and the Gly-G17 hormone. Gastrin 17 is a growth factor for pancreatic, stomach and colorectal cancers, and a potent stimulator of gastric acid secretion.The anti-gastrin immunogen, G17DT, consists of a large carrier protein, called Diptheria Toxoid (DT). A synthetic peptide, which is similar to a portion of the gastrin 17 hormone (GT), is attached to the carrier protein. These are then contained in a liquid suspension vehicle. When administered to patients, G17DT induces an immune response producing antibodies, which cross-react and neutralise the target hormone thus preventing its interaction with disease-causing or -participating cells. Aphton has entered into an agreement with Aventis Pasteur for the marketing of G17DT in all human cancer indications in North America and Europe. Under the terms of the agreement, Aphton is responsible for product development, clinical trials and regulatory agency approvals. The agreement was originally with Pasteur Mérieux Connaught, a subsidiary of Rhône-Poulenc. However, in December 1999, Rhône-Poulenc merged with Hoechst to form Aventis. As a result of the merger, Pasteur Mérieux Connaught underwent a name change to Aventis Pasteur. In July 2002, Aphton announced that it would negotiate with companies wanting to licence the vaccine in territories other than North America and Europe. In February 2003, Aphton announced it had received fast track designation for G17DT in combination with cisplatin and fluorouracil for use in stage IV gastric cancer to improve overall survival. In July 2002, the US FDA granted G17DT orphan drug status for the treatment of gastric cancer, an indication that was broader than the indication Aphton originally sought. The vaccine was also granted orphan drug status in Australia for gastric cancer in December 2002. In July 2002, Aphton announced that the US FDA had granted G17DT orphan drug status for the treatment of adenocarcinoma of the pancreas. In September 2002, the US FDA also granted G17DT, used in combination with gemcitabine, fast track status for the treatment of pancreatic cancer patients. In addition, the vaccine was also granted orphan drug status in Australia for pancreatic cancer in December 2002. In March 2003, Aphton announced that the Committee for Orphan Medicinal Products had recommended to the European Commission that G17DT be granted orphan drug status for both pancreatic and gastric cancer in the EU. Aphton expects this will be approved and ratified within a few weeks. In August 2002, Aphton filed an IND with the US FDA, as well as the European equivalent, to conduct clinical trials for patients suffering from gastro-esophophageal reflux disease (GERD). The trials will assess, among other endpoints, the efficacy of G17DT in providing symptomatic relief to patients with GERD. In November 2002, Aphton announced that it had received approval to initiate a clinical trial in Europe. Additionally, Aphton has agreed with the FDA to conduct toxicology and other preclinical studies prior to initiation of a trial in the US. Patient recruitment for the European study was scheduled to begin in January 2003.

Anti-CagA and anti-VacA antibodies in Helicobacter pylori-infected patients with and without peptic ulcer disease in Serbia and Montenegro

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.

[A study of the immunological status in patients with stomach ulcer during acute conditions and remission]

The interest shown in the functioning of the immunity system at ulcer is mainly stipulated by newly emerged methods of diagnosing and treating patients, which have broadened our insight into the pathogenesis of the disease. The study of the nature of immunological improvements observed in the peripheral blood of patients with stomach ulcer enables us to find a differential approach to the correction of the inflammatory process.

[State of humoral immunity and phagocytic activity of neutrophils in patients with ulcer and effect of low-intensity laser therapy]

The aim of our investigation was to study the influence of low-intensity laser therapy at the immunologic parameters and Helicobacter pylori (HP) microbial contamination in patients with exacerbation of peptic and duodenal ulcer. 100 patients aged 18-65 were examined and divided into 2 groups. The experimental group (75 patients) underwent a complex drug and laser therapy of various therapeutic techniques. The control group (25 patients) underwent only drug therapy. The results of this study show the immunocorrective effect of different methods of low-intensity laser therapy in the exacerbation period and more essential decrease of HP microbial contamination in the experimental group.

Is the host responsible? – the role of the immune system in Helicobacter pylori infection

Helicobacter pylori is the primary aetiological agent of chronic gastritis and a necessary factor in most peptic ulcer disease. To date the majority of studies, which have examined factors predictive of disease outcome, have concentrated on bacterial virulence factors. Recent evidence suggests that the immune response might be responsible. Fc receptors polymorphisms have been implicated in autoimmune diseases and persistent bacterial infections. Individuals who are H. pylori positive and homozygous recessive for the FcgammaRIIa receptor may have a higher risk of developing peptic ulcer disease rather than gastritis.

Evaluation of a newly developed office-based stool test for detecting Helicobacter pylori: an extensive pilot study

BACKGROUND/AIMS

Several strategies have been used to detect Helicobacter pylori (Hp) infection along two lines: 1) direct detection of the bacteria, and 2) detection of antigen-antibody assay against Hp. The non-invasive methods include ELISA test of serum, salivary and urine, urea breath test, and detection of Hp antigen in stool. The latter method (HpSA) has been proven reliable and better than the ELISA test, for it can detect current Hp infection and is suitable for post-treatment follow-up. Now, a new commercial kit, ImmunoCard STAT HpSA (Meridian Bioscience Europe) has been developed to detect stool Hp antigen. It is simpler and less time-consuming than HpSA. The aim was to examine whether ImmunoCard STAT HpSA is qualified for diagnosis of Hp infection.

METHODOLOGY

253 patients (163 men, 90 women, mean age: 53.3 +/- 13.9 y/o, range: 19-89 y/o) were enrolled in this study. All of them had undergone gastroendoscopy and urea breath test. 207 patients were diagnosed with peptic ulcer and 46 with gastritis. Stool samples were collected within 3 days of their visit for gastroendoscopy and were sent for the Immunocard test.

RESULTS

118 patients were diagnosed with Hp infection and of these, 113 were interpreted as positive by means of the Immunocard test. Among the other 135 patients without Hp infections, 123 were interpreted as negative by means of the Immunocard test. Sensitivity and specificity were 95.8% and 91.1%, and positive and negative predictive values were 90.4% and 96.1%.

CONCLUSIONS

The ImmunoCard STAT HpSA had high sensitivity, and specificity and could be used for mass screening. We concluded that it is a rapid, simple, cheap, reliable, and non-invasive strategy to detect current Hp infection and can be used in post-Hp eradication follow-up in Taiwan.

Gastric mucosal cytokine responses in Helicobacter pylori-infected patients with gastritis and peptic ulcers. Association with inflammatory parameters and bacteria load

Helicobacter pylori is an important pathogen in gastroduodenal inflammation and ulceration. Several mechanisms have been proposed to explain its role. We studied the cytokine production patterns in situ in gastric mucosal biopsies from H. pylori-positive and H. pylori-negative patients with dyspepsia. Immunohistochemistry with monoclonal antibodies was used. The study showed enhanced expression of interleukin (IL) -8, IL-10 and interferon-gamma (IFN-gamma) in H. pylori infection and a significant association was found between these cytokines and the following parameters: bacteria load, chronic inflammation and activity. These parameters were significantly correlated with the cell markers CD19 and CD56. The study indicates a dual effect of H. pylori on the Th1 response, i.e. a stimulation of the response verified by increased IFN-gamma and a feed-back verified by an increase of the counterinflammatory IL-10, which may dampen the inflammatory and cytotoxic effect of the Th1 response. Furthermore, the study confirms the connection between increase of IL-8 and inflammatory activity in gastric mucosa in H. pylori infection.

Eradication therapy of Helicobacter pylori directly induces apoptosis in inflammation-related immunocytes in the gastric mucosa--possible mechanism for cure of peptic ulcer disease and MALT lymphoma with a low-grade malignancy

BACKGROUND/AIMS

A possibility that the eradication therapy not only eliminates Helicobacter pylori (H. pylori) but also influences some factors regulating pathological changes in the gastric mucosa should be taken into consideration from some phenomena. Such as non-recurrent cases of peptic ulcer long-term in spite of unsuccessful anti-H. pylori eradication therapy and the effectiveness of eradication therapy for mucosa-associated lymphoid tissue with a low-grade malignancy except stomach. We hypothesized and investigated that antibiotic treatment for elimination of H. pylori might directly affect inflammatory cells to induce apoptosis in them and protect against pathological changes of gastric mucosa.

METHODOLOGY

Subjects consisted of twenty-one patients with chronic gastritis. All were H. pylori positive and we investigated the effects of eradication therapy of H. pylori on inflammation-related immunocytes in the gastric mucosa of patients with chronic gastritis caused by H. pylori isolated mononuclear leukocytes which were taken from the patients and were examined for apoptosis-related morphological changes and DNA fragmentation before and after the therapy. Eradication therapy of H. pylori was performed by lansoprazole 30 mg/day, amoxicillin 1500 mg/day and clarithromycin 400 mg/day for one week.

RESULTS

After the H. pylori eradication therapy, regardless of its effect on H. pylori status, marked vacuolation and degeneration were observed in mononuclear leukocytes in the gastric mucosa with a concomitant enhancement of nuclear DNA fragmentation.

CONCLUSIONS

This observation suggests that H. pylori eradication therapy itself induces apoptosis in mononuclear leukocytes in the gastric mucosa.