Evidence for Local and Systemic Immune Activation in Functional Dyspepsia and the Irritable Bowel Syndrome: A Systematic Review

BACKGROUND

Subtle histopathologic features such as eosinophilia and increased mast cells have been observed in functional gastrointestinal disorders (FGIDs), including functional dyspepsia (FD) and the irritable bowel syndrome (IBS). The mechanisms that drive recruitment of these cells to the gastrointestinal tract remain unexplained, largely due to the heterogeneity in phenotypes among patients diagnosed with such conditions. We aimed to systematically review the literature and collate the evidence for immune activation in FD and IBS, and where possible, detail the nature of activation.

METHODS

Seven literature databases were searched using the keywords: 'functional gastrointestinal disorder', FGID, 'functional dyspepsia', 'non-ulcer dyspepsia', 'idiopathic dyspepsia', 'irritable bowel syndrome', IBS and 'immun*'.

RESULTS

Fifty-one papers reporting discordant immune features met the selection criteria for this review. Changes in lymphocyte populations, including B and T lymphocyte numbers and activation status were reported in IBS and FD, in conjunction with duodenal eosinophilia in FD and increased colonic mast cells in IBS. Increases in circulating α4+β7+ gut-homing T cells appear to be linked to the pathophysiology of both FD and IBS. Studies in the area are complicated by poor phenotyping of patients into subgroups and the subtle nature of the immune activity involved in FD and IBS.

CONCLUSIONS

Alterations in proportions of gut-homing T lymphocytes in both FD and IBS indicate that a loss of mucosal homeostasis may drive the symptoms of FD and IBS. There is indirect evidence that Th17 responses may play a role in FGIDs, however the evidence for a Th2 immune phenotype in FD and IBS is limited. Although immune involvement is evident, large, well-characterised patient cohorts are required to elucidate the immune mechanisms driving the development of FGIDs.

Immunopathological and molecular basis of functional dyspepsia and current therapeutic approaches

INTRODUCTION

Functional dyspepsia (FD) is widespread with 20% prevalence worldwide and a significant economic burden due to health care cost and constraints on daily activities of patients. Despite extensive investigation, the underlying causes of dyspepsia in a majority of patients remain unknown. Common complaints include abdominal discomfort, pain, burning, nausea, early satiety, and bloating. Motor dysfunction of the gut was long considered a major cause, but recent investigations suggest immune-based pathophysiological and molecular events in the duodenum are more probable contributing factors. Areas Covered: Inflammatory mediators and immune cells including duodenal eosinophils, intraepithelial lymphocytes, and T-cells have been implicated in the underlying cause of disease process, as have genetic factors. In this article, we critically reviewed findings, identified gaps in knowledge and suggested future directions for further investigation to identify targets and develop better therapeutic approaches. Expert commentary: Impaired gastric accommodation, slow gastric emptying, and increased visceral sensitivity have long been thought of as main causal factors of FD. However, more recent identification of eosinophilic degranulation and recruitment of T cells that induce mild duodenal inflammation are giving rise to new insights into immune-mediated pathophysiology. These insights offer promising avenues to explore for immune-mediated therapy in the future.

Gastric corticotropin-releasing factor influences mast cell infiltration in a rat model of functional dyspepsia

Functional gastrointestinal disorders (FGIDs) are characterized by dysregulated gut-brain interactions. Emerging evidence shows that low-grade mucosal inflammation and immune activation contribute to FGIDs, including functional dyspepsia (FD). Stress plays an important role in the onset of FD symptoms. In human subjects with FD, presence of gastric mast cells has been reported, but factors that influence mast cell infiltration remain uncharacterized. Corticotropin-releasing factor (CRF) initiates the body's stress response and is known to degranulate mast cells. In this study, we delineated the role of the CRF system in the pathogenesis of FD in a rat model. Gastric irritation in neonate rat pups with iodoacetamide (IA) was used to induce FD-like symptoms. RNA interference (RNAi) was used to silence gastric CRF expression. Mast cell infiltrate in the stomach increased by 54% in IA-treated rats compared to controls and CRF-RNAi tended to decrease gastric mast cell infiltrate. Sucrose intake decreased in IA-treated rats and mast cell numbers showed a negative association with sucrose intake. IA treatment and transient silencing of gastric CRF increased hypothalamic CRF levels. In IA-treated rats, gastric levels of CRF receptor 2 (CRF2) decreased by ~76%, whereas hypothalamic CRF receptor 1 (CRF1) levels increased. Plasma levels of TNF-α showed a positive correlation with plasma CRF levels. Levels of phosphorylated p38 and ERK1/2 in the stomach showed a positive correlation with gastric CRF levels. Thus, CRF may contribute to low grade inflammation via modulating mast cell infiltration, cytokine levels, MAPK signaling, and the gut-brain axis.

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.

Immune dysregulation in the functional gastrointestinal disorders

Gastrointestinal conditions may be broadly classified into two: organic and functional disease, with functional disorders accounting for the majority of patients with chronic gastrointestinal symptoms. Functional gastrointestinal disorders (FGIDs) present with no obvious pathology or well-accepted biochemical mechanism and, as such, treatment strategies are limited and focus on symptoms rather than cure. Irritable bowel syndrome and functional dyspepsia are the most widely recognised FGIDs, and there is a growing body of evidence to suggest an underlying inflammatory phenotype in subsets with these conditions. Here, we discuss the current knowledge of immune involvement in FGIDs and the commonalities between the different manifestations of FGIDs and propose a new hypothesis, potentially defining an underlying immunopathological basis of these conditions.

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.

Helicobacter pylori infection in patients with selective immunoglobulin E deficiency

AIM: To investigate the prevalence and clinical characteristics of Helicobacter pylori (H. pylori)-infected dyspeptic patients with selective immunoglobulin E deficiency (IgEd).

METHODS: All individuals who underwent serum total immunoglobulin E (IgE) measurement at the Leumit Healthcare Services (Israel) in 2012 were identified in an electronic database search (n = 18487). From these, selected case group subjects were ≥ 12 years of age and had serum total IgE < 2 kIU/L (n = 158). The control group was selected from a random sampling of the remaining subjects ≥ 12 years of age to obtain a case-control ratio of 1:20 (n = 3160). Dyspeptic diseases, diagnosed no more than 5 years before serum total IgE testing, were identified and retrieved from the electronic database using specific International Classification of Diseases diagnostic codes. Results of C¹³-urea breath tests were used to identify subjects infected with H. pylori. Categorical variables between case and control subjects were analyzed using Fisher’s exact tests, whereas continuous variables were analyzed using χ² tests.

RESULTS: Dyspepsia was present in 27.2% (43/158) of case subjects and 22.7% (718/3160) of controls. Of these, significantly more case subjects (32/43, 74.4%) than controls (223/718, 31.1%) were positive for H. pylori (P < 0.01). Esophagogastroduodenoscopy was performed in 19 case and 94 control subjects, revealing that gastritis was more prevalent in IgEd case subjects than in controls (57.9% vs 29.8%, P < 0.05). Furthermore, a significantly greater proportion of case subjects presented with peptic duodenal ulcers (63.2% vs 15.9%, P < 0.01). Histopathologic examination showed marked chronic inflammation, lymphoid follicle formation and prominent germinal centers, with polymorphonuclear cell infiltration of gastric glands, that was similar in case and control biopsy tissues. Finally, IgEd case subjects that underwent esophagogastroduodenoscopy were more likely to exhibit treatment-refractory H. pylori infections that require second-line triple antibiotic therapy (47.4% vs 11.7%, P < 0.01).

CONCLUSION: IgEd is associated with higher rates of H. pylori-associated gastritis and peptic duodenal ulcers.

Efficacy and mechanism of action of yin lai tang (lung-stomach treatment) in dyspepsia mouse infected by FM1 virus

The aim of this study was to assess the efficacy and elaborate the mechanism of action of Yin Lai Tang (Lung-Stomach Treatment) on dyspepsia mouse infected by FM1 virus. Ninety male, 4 week old Kunming mouse with 12-14 g weight, were randomly divided into 9 groups, i.e., normal, infected, dyspepsia, ribavirin, Shuanghuanglian, Children's indigestion tablet, YinLaiTang high dose, YinLaiTang middle dose and YinLaiTang low dose, and these groups had been treated by according drugs to get objectives. Compared with normal group, lung index significantly (p < 0.01) increased in all groups except ribavirin group where lung index obviously (p < 0.05) increased. There was non-significant (p > 0.05) difference in the values of lung homogenate virus titer between dyspepsia group and other groups. Compared to normal group, there was variable degree of inflammatory cell infiltrations in respiratory tract structures in the animals of other groups, and there was a significant (p < 0.01) increase in the level of serum IL-6, IL-10, and TNF-alpha in infected and dyspepsia group and significant (p < 0.01) decrease in the level of serum IFN-gamma was observed. Compared with single clearing stomach method and single clearing lung approach, lung-stomach treatment reduced the level of IL-6 with non-significant difference (p > 0.05) and increased the level of IL-10 obviously, and compared with the single clearing lung method, there was a significant difference (p < 0.05). Compared with the single clearing stomach method and the single clearing lung method, the lung-stomach treatment method had a better efficacy and showed effects on the expression of pro-inflammatory factor and anti-inflammatory factor.

The study on the role of inflammatory cells and mediators in post-infectious functional dyspepsia

OBJECTIVE

Functional dyspepsia is a common gastrointestinal disorder. The pathogenesis of functional dyspepsia remains unclear. Functional dyspepsia may begin after a bout of gastroenteritis (post-infectious functional dyspepsia) or de novo (nonspecific functional dyspepsia). The aim of this study was to investigate the prevalence and probable mechanisms of post-infectious functional dyspepsia.

MATERIAL AND METHODS

Functional dyspepsia patients with a history of unsanitary food intake and acute gastroenteritis 6-12 months ago were enrolled. (13)C-UBT confirmed absence of H. pylori infection. Controls consisted of healthy nondyspeptic volunteers and patients with nonspecific functional dyspepsia. Gastric biopsies were used for routine histology, immunohistochemistry, electron microscopy, ELISA, HPLC assays and Western blot examination.

RESULTS

Eighty-five subjects were entered including 35 with post-infectious functional dyspepsia, 30 with nonspecific functional dyspepsia, and 20 healthy controls. The number of mast cells in post-infectious functional dyspepsia and nonspecific functional dyspepsia were significantly greater than that in healthy controls. The number of enterochromaffin cells (ECs) in post-infectious functional dyspepsia was significantly higher than those in nonspecific functional dyspepsia or in healthy controls. The number of mast cells and ECs increased with the density of chronic inflammatory cells. The release of histamine and 5-hydroxytryptamine from gastric mucosa of post-infectious functional dyspepsia patients was significantly greater than those from nonspecific functional dyspepsia or healthy controls. Tryptase protein expression was higher in post-infectious functional dyspepsia and nonspecific functional dyspepsia than in healthy controls. The histological score of chronic gastric inflammation was greater in post-infectious functional dyspepsia versus patients with nonspecific functional dyspepsia or healthy controls. Electron microscopy showed secreting granules in the cytoplasm of both mast cells and ECs. The number of activated mast cells and Ecs at a distance of < 5 microm of nerve fibers were significantly greater in post-infectious functional dyspepsia versus nonspecific functional dyspepsia or controls.

CONCLUSIONS

Dyspepsia may occur after an acute onset of gastroenteritis in a part of patients. Potent chemicals derived from mast cells and ECs, including histamine, tryptase and 5-hydroxytryptamine may be involved in the pathogenesis of post-infectious functional dyspepsia.

Duodenal mastocytosis, eosinophilia and intraepithelial lymphocytosis as possible disease markers in the irritable bowel syndrome and functional dyspepsia

BACKGROUND

Irritable bowel syndrome (IBS) and functional dyspepsia (FD) are common functional disorders without defined pathology. Mast cells and eosinophils interact with T lymphocytes and may alter enteric nerve and smooth muscle function.

AIM

To examine mast cell, eosinophil and intraepithelial lymphocyte populations in duodenal biopsies of subjects with IBS and FD.

METHODS

A random sample of an adult Swedish population (n = 1001; mean age 54 years; 51% female) underwent upper endoscopy and biopsy; 51 cases with FD and 41 cases with IBS were compared with 48 randomly selected controls. Eosinophils were identified by light microscopy; mast cells by immunocytochemistry (CD117). Intraepithelial lymphocytes were counted per 100 enterocytes. Cell counts were quantified by counting the number per high power field (HPF) in 5HPFs in the bulb (D1) and second part of duodenum (D2), summed over 5HPFs at each site.

RESULTS

Cases and controls showed similar demographics. Compared to controls, IELs in IBS-constipation were significantly increased (P = 0.005). Mast cells were significantly increased in IBS in D2 (P < 0.001), while eosinophils were significantly increased in FD in D1 and D2 (P < 0.001).

CONCLUSION

Duodenal mast cell hyperplasia is linked to IBS and eosinophilia to FD, and duodenal biopsy may identify subsets of these disorders.

Anti CagA antibody among patients with non-cardia gastric cancer in comparison with non-ulcer dyspepsia in an area with high incidence of gastric cancer

OBJECTIVE

To evaluate the correlation between anti CagA antibody (Ab) and presence of gastric cancer.

METHODS

In a descriptive cross-sectional study during October 2003 to October 2005, in the Gastrointestinal Subspeciality Center in Razi Hospital, Rasht, Iran, we assessed anti-Helicobacter Ab immunoglobulin G (IgG) and anti CagA Ab IgG by the enzyme-linked immunosorbent assay (ELISA) method in 52 patients with gastric adenocarcinoma and 57 patients with nonulceric dyspepsia (NUD).

RESULTS

Among 52 patients with gastric cancer, anti-Helicobacter pylori Ab was negative in 13 (25%) and positive in 39 persons (75%). Among 57 patients with NUD, anti-Helicobacter pylori Ab was negative in 5 (8.5%) and positive in 52 patients (91.2%) (p=0.043). This significant difference did not remain after logistic regression for adjustment of confounders (p=0.068). The CagA Ab was positive in 22 (42.3%) patients with cancer and 32 (56.1%) of the NUD group. There was no difference in this regard before (p=0.212) and after (p=0.131) logistic regression analysis.

CONCLUSION

Anti CagA Ab does not have a significant value as an independent predictive factor in gastric adenocarcinoma.

Helicobacter pylori in allergic inflammation--fact or fiction?

BACKGROUND

Although it has been hypothesized that infections may play a preventive role in allergic diseases, the role of Helicobacter pylori (H. pylori) is not clear. In this study we aimed to determine the association between H. pylori infection and allergic inflammation.

METHODS

H. pylori infection was assessed in gastric mucosa tissue by microscopy. Skin prick tests (SPT) were performed with a battery of common inhalant and certain food allergens. Serum samples were tested for total immunoglobulin E (T.IgE). Predictive factors for H. pylori infection and atopy were examined by a questionnaire.

RESULTS

A total of 90 subjects suffering dyspeptic symptoms were enrolled into the study. SPT positivity was similar between H. pylori (+) and H. pylori (-) subjects. Among the possible factors examined: age; gender; educational status; pet at home; BMI, family size; number of children and siblings; monthly income; drinking water source; smoking; and serum T.IgE levels were not related with H. pylori infection. However, perennial allergic symptoms were significantly higher in the H. pylori (-) group, seasonal allergic symptoms were related with an increased risk for H. pylori infection.

CONCLUSIONS

In this sample group from a developing country H. pylori infection was not shown to be associated with atopic diseases. Therefore, the eradication of H. pylori may not be assumed to have an effect on allergic inflammation.

Alterations of food antigen-specific serum immunoglobulins G and E antibodies in patients with irritable bowel syndrome and functional dyspepsia

BACKGROUND

Post-prandial worsening of symptoms as well as adverse reactions to one or more foods are common in the patients with functional gastrointestinal diseases, such as irritable bowel syndrome (IBS) and functional dyspepsia (FD). However, the role played by true food allergy in the pathogenesis of these diseases is still controversial and there are no well-established tests to identify food allergy in this condition.

OBJECTIVE

To investigate serum food antigen-specific IgG, IgE antibody and total IgE antibody titres in controls and patients with IBS and FD, and to correlate symptoms with the food antigen-specific IgG titres in IBS and FD patients.

METHODS

Thirty-seven IBS patients, 28 FD patients and 20 healthy controls participated in this study. Serum IgG and IgE antibody titres to 14 common foods including beef, chicken, codfish, corn, crab, eggs, mushroom, milk, pork, rice, shrimp, soybean, tomatoes and wheat were analysed by ELISA. Serum total IgE titres were also measured. Last, symptomatology was assessed in the study. Results IBS patients had significantly higher titres of IgG antibody to crab (P=0.000), egg (P=0.000), shrimp (P=0.000), soybean (P=0.017) and wheat (P=0.004) than controls. FD patients had significantly higher titres of IgG antibody to egg (P=0.000) and soybean (P=0.017) than controls. The percentage of individuals with detectable positive food antigen-specific IgE antibodies of the three groups did not show any significant differences (P=0.971). There were no significant differences between IBS patients, FD patients and controls in the serum total IgE antibody titres (P=0.978). Lastly, no significant correlation was seen between symptom severity and serum food antigen-specific IgG antibody titres both in IBS and FD patients.

CONCLUSION

Serum IgG antibody titres to some common foods increased in IBS and FD patients compared to controls. But there is no significant correlation between symptom severity and elevated serum food antigen-specific IgG antibodies in these patients.

Genetic polymorphisms of molecules associated with inflammation and immune response in Japanese subjects with functional dyspepsia

Inflammatory changes in the gastric mucosa are commonly observed in Japanese patients with functional dyspepsia (FD). However, detailed data regarding the relationship between the genetic regulatory factors of inflammation and FD are not available. We investigated the associations between FD and genetic polymorphisms of molecules associated with inflammation or immune response (IL-17A, -17F and MIF). The study was performed with 278 subjects (188 with no upper abdominal symptoms and 90 with FD according to the Roma III criteria). We employed the PCR-SSCP (multiplex PCR for IL-17A and -17F) method to detect the gene polymorphisms. Overall, the polymorphisms of the IL-17A, -17F and MIF genes were not correlated with the susceptibility to FD. However, the MIF -173C allele carrier had a significantly increased risk for the development of epigastric pain syndrome (EPS) of FD (OR, 2.12; 95% CI, 1.00-4.49; p=0.0497). In Helicobacter pylori (H. pylori)-infected cases, the number of IL-17F 7488T alleles was positively correlated with the development of EPS (OR, 11.3; 95% CI, 1.23-103.2; p=0.032), while the IL-17F T/T homozygote and the MIF -173C carrier had an increased risk for EPS (OR, 10.4; 95% CI, 1.17-92.3; p=0.036 and OR, 3.66; 95% CI, 1.19-11.3; p=0.024, respectively). In addition, a significant interaction between the IL-17F 7488 polymorphism and H. pylori infection was shown to increase the activity and inflammation scores (p=0.043 and 0.042, respectively). There were no significant associations between the IL-17A polymorphism and FD. Our results provide the first evidence that the IL-17F and MIF gene polymorphisms are significantly associated with the development of FD, particularly EPS, a subgroup of FD, in H. pylori-infected subjects. The genetic polymorphisms of inflammation or immune response-related molecules are involved in the development of one of the FD subgroups via H. pylori-induced gastric inflammation.

Helicobacter pylori infection can change the intensity of gastric Lewis antigen expressions differently between adults and children

This study tested whether there were different expressions of gastric Lewis antigens between children and adults with Helicobacter pylori infection, and whether the difference was related to the infection outcome. About 68 dyspeptic children and 110 dyspeptic adults were enrolled to check H. pylori infection, its colonization density, and the related histology. Gastric Lewis antigens b (Le(b)), x (Le(x)), and sialyl-Lewis x (sialyl-Le(x)) were immunohistochemically stained and scored for the intensity. The H. pylori-infected adults, but not the children, had a lower Le(b) intensity over the antrum (p=0.019) but higher Le(b) intensity over the corpus (p=0.001) than the non-infected ones. Over the antrum, both the H. pylori-infected children and adults had a lower Le(x) and higher sialyl-Le(x) intensity than those non-infected ones (p<0.05). The H. pylori-infected adults had a higher bacterial density (p=0.004) and Le(b) intensity (p=0.016) over the corpus than the H. pylori-infected children. For the H. pylori-infected adults, but not children, the corpus had a higher Le(b) (p=0.038) and lower Le(x) (p=0.005) intensity than the antrum. Furthermore, the H. pylori-infected adults expressed a higher Le(b) and had a higher bacterial density than those with weak Le(b) (antrum, p<0.001; corpus, p=0.001). In conclusion, H. pylori infection is associated with the intensity change of Lewis antigen expressions in the stomach. The changes of gastric Lewis antigen expressions are different between adults and children with H. pylori infection, which may exert different H. pylori colonization over the corpus between adults and children.

Duodenal intraepithelial T lymphocytes in patients with functional dyspepsia

AIM: To quantify the intraepithelial lymphocytes (IELs) and to document the membrane expression of CD4, CD8, TCRγδ and adhesion and/or activation-associated molecules (CD103, CD28, CD44, CD69, HLA-DR, CD95/Fas) in the duodenal mucosa of patients with functional dyspepsia (FD) in order to provide arguments for an immunological process in FD.

METHODS: Twenty-six FD patients according to Rome II criteria (20 were H pylori negative) were studied and compared to 12 healthy adults. IELs were isolated from five duodenal biopsy samples, then quantified by microscopy and flow cytometry while the membrane phenotypes were determined by cytofluorometry.

RESULTS: Duodenal histological examination was normal. In H pylori negative patients, the number of IELs was not different from that in healthy controls. Median percentage expression of CD4, CD8, or TCRγδ and CD103, CD44, CD28, CD69 on CD3+ IELs, among the adhesion/activation associated molecules tested, was not different from that in healthy controls. In contrast, the median percentage expression of CD95/Fas [22 (9-65) vs 45 (19-88), P = 0.03] and HLA-DR expressing CD3+ IELs [4 (0-30) vs 13 (4-42), P = 0.04] was significantly lower in the H pylori negative FD group than in healthy controls, respectively. The number of IELs was significantly greater in H pylori positive FD patients than in healthy controls [median ratiofor 100 enterocytes 27.5 (6.7-62.5) vs 10.8 (3-33.3), P = 0.02] due to a higher number of CD8+ CD3+ IELs.

CONCLUSION: In H pylori negative FD patients, the phenotypic characterization of IELs suggests that we cannot exclude a role of IELs in FD.

Analysis of serum antibody profile against H pylori VacA and CagA antigens in Turkish patients with duodenal ulcer

AIM

To investigate the frequency of seropositivity against CagA, VacA proteins and to determine their independent effects on the development of duodenal ulcer (DU) in Turkish patients.

METHODS

The study was designed as a prospective one from a tertiary referral hospital. Dyspeptic patients who were referred to our endoscopy unit for upper gastrointestinal endoscopy between June 2003 and March 2004 and diagnosed to have DU or nonulcer dyspepsia (NUD) were included. Biopsies from the antrum and body of the stomach were taken in order to assess the current H pylori status by histology, rapid urease test and culture. Fasting sera were obtained from all patients and H pylori status of all sera was determined by IgG antibodies using an enzyme-linked immunosorbent assay (ELISA) kit. All seropositive patients were further analysed using Western blot assays detecting IgG antibodies against CagA and VacA proteins. The c2 test was used for statistical comparison of the values and age-sex adjusted multiple regression analysis was used to determine the independent effects of CagA and VacA seropositivities on the development of DU.

RESULTS

Sixty-three patients with DU and 62 patients with NUD were eligible for the final analysis. Seropositivity for anti-CagA was detected in 51 of 62 (82%), and in 55 of 63 (87%) patients with NUD and DU, respectively (P = no significance), and seropositivity for anti-VacA was found in 25 of 62 (40% ) and in 16 of 63 (25%) patients, with NUD and DU, respectively.

CONCLUSION

These findings suggest that none of these virulence factors is associated with the development of DU in the studied Turkish patients with dyspepsia.

Is there a role of food allergy in irritable bowel syndrome and functional dyspepsia? A systematic review

A significant proportion of adults believe they suffer from food allergy, and 20-65% of patients with irritable bowel syndrome (IBS) attribute their symptoms to something in food that activates an abnormal response. This systematic review evaluates the role of food allergy in aetiology and management of these disorders. Activation of gastrointestinal mucosal immune system may be one of the causative factors in the pathogenesis of functional dyspepsia and IBS. This activation may result from effects of bacterial infection or other luminal factors including commensal microbial flora and food antigens. Some studies have reported on the role of food allergy in IBS; only one epidemiological study on functional dyspepsia and food allergy has been published. The mechanism by which food activates mucosal immune system is uncertain, but food specific IgE and IgG4 appeared to mediate the hypersensitivity reaction in a subgroup of IBS patients. Exclusion diets based on skin prick test, RAST for IgE or IgG4, hypoallergic diet and clinical trials with oral disodium cromoglycate have been conducted, and some success has been reported in a subset of IBS patients. Further well-controlled studies are needed to establish whether food allergy plays a role in the pathophysiology of functional dyspepsia and IBS.

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.

Immunity markers in patients with Helicobacter pylori infection: effect of eradication

BACKGROUND

Helicobacter pylori is a microorganism able to stimulate a robust inflammatory and systemic immune response.

AIM

The aim of our study was to evaluate autoimmune markers in dyspeptic patients positive for H. pylori infection compared to a control group of non-H. pylori-infected subjects. The kinetics of cryoglobulins and autoantibodies was evaluated after treatment of the infection.

PATIENTS AND METHODS

Dyspeptic patients with active H. pylori infection and age- and sex-matched healthy H. pylori-negative controls were studied. Markers of immunity were compared, in H. pylori-infected patients before, 6 months and 1 year after the end of therapy. Results were also compared between those with and without successful eradication therapy.

RESULTS

Eighty-six individual were entered (43 H. pylori-infected). H. pylori-infected patients had higher levels of IgG and/or IgA and/or IgM (22/43 versus 2/43). Circulating immune complexes and cryoglobulins were detected in patients more often than controls (p < .05 for both). Autoantibodies were observed in 13 patients (30% versus 5% in controls) and antithyroid antibodies in 12 (p < .04 versus controls). Lower levels of C3 and/or C4 complement fractions were observed in infected patients with respect to controls (7/43 versus 1/43; p = .014). After 1 year of follow-up, the markers of autoimmunity dramatically improved in patients eradicated for H. pylori infection compared to those in whom therapy failed. No patient developed a clinical autoimmune disorder.

CONCLUSIONS

Additional studies are necessary to ascertain the clinical significance of the modifications of autoimmune markers in patients with H. pylori infection.

Gastric inflammatory markers and interleukins in patients with functional dyspepsia, with and without Helicobacter pylori infection

Helicobacter pylori is the most important cause of gastritis, peptic ulcers and the development of gastric cancer. The chronic active inflammation is dominated by neutrophils, macrophages, lymphocytes and plasma cells. Several interleukins (IL-8, IL-10 and IFN-gamma) are involved in the inflammatory process in the gastric mucosa. The aim of this study was to investigate the gastric inflammation in patients with functional dyspepsia. Fifty-three consecutive patients were included and antral biopsies were obtained for histology, culture and immunohistochemistry. The sections were examined for the interleukins IL-4, IL-6, IL-8, IL-10 and IFN-gamma as well as for the cell markers CD4, CD8, CD14, Cd19, CD25 and CD30. Only CD4 and CD19 were significantly increased in patients with increased gastric inflammation and increased density of H. pylori. However, several of the examined markers (IFN-gamma, IL-8, IL-10 and CD14) showed a non-significant trend to be increased in patients with extensive gastric inflammation and high density of H. pylori. Therefore, an arbitrary index (IM11) for all the 11 immunological markers was made as an average value for each of the four morphological groups. For the four morphologically different groups of patients the values were 0.49, 0.77, 0.86 and 1.25, respectively. Significant increases in the index from none to moderate antral inflammation as well as the density of H. pylori were found (p<0.001). By using an index of inflammatory markers trends can be summarized and thereby significant which may be of importance when gastric inflammation is investigated in children and patients with functional dyspepsia.

Dyspeptic complaints after 20 weeks of gestation are not related to Helicobacter pylori seropositivity

BACKGROUND

This study was to test whether an association exists between Helicobacter pylori seropositivity and severity of dyspeptic symptoms after 20 weeks of gestation in pregnant women.

MATERIAL/METHODS

Pregnant women (n=103) with gestational ages between 20-41 weeks and healthy non-pregnant women (controls, n=79) were prospectively enrolled in the study. Anti-H. pylori IgG serum antibody was tested to establish seropositivity. The dyspeptic symptoms were evaluated by the Glasgow Dyspepsia Severity Score in the pregnant group and classified as asymptomatic (score 0), mildly symptomatic (score 1-5), and severely symptomatic (score > or = 6). The severity of dyspeptic symptoms was compared in pregnant women with H. pylori seropositivity, and pregnant and non-pregnant women were compared for H. pylori seropositivity and prevalence of dyspeptic symptoms. The results were analyzed using Student's t, Mann-Whitney-U, and chi-square tests.

RESULTS

The prevalence of H. pylori seropositivity was not different among pregnant and non-pregnant women. The median dyspeptic scores were 5 and 4, respectively, for H. pylori seropositive and negative pregnant women. Dyspeptic scores of H. pylori seropositive pregnant women were not different from those of uninfected pregnant women. H. pylori seropositivity did not differ among asymptomatic and mildly and severely symptomatic pregnant women. The non-pregnant women were more often asymptomatic than pregnant women.

CONCLUSIONS

Our findings do not support any association between H. pylori seropositivity and severity of dyspeptic symptoms in late pregnancy. It seems unreasonable to screen women in late pregnancy for H. pylori seropositivity, even if they suffer from severe dyspeptic symptoms.

Chronic gastritis is not associated with gastric dysrhythmia or delayed solid emptying in children with dyspepsia

To determine if chronic gastritis (CG) is associated with gastric dysrhythmia or delayed solid emptying in children with dyspepsia, 22 patients (7-15 years of age) with dyspepsia and normal gross endoscopies were studied. Antral biopsies were evaluated for chronic gastritis, and immunohistology was performed to determine densities of CD3+, CD20+, CD25+, and tryptase-positive cells. Electrogastrography (EGG) and gastric scintiscan evaluation were performed within 2-7 days of endoscopy. CG and increased immune cell densities were not associated with altered gastric emptying. Mean CD3+ cell counts were positively correlated with the percentage normal slow waves, and patients with a normal EGG had increased CD3+ cell density. In children with dyspepsia, chronic antral inflammation in the setting of a normal gross endoscopy is not associated with EGG abnormalities or delayed solid emptying. Chronic gastritis and gastric dysrhythmia may simply be two separate and distinct mechanisms resulting in the clinical entity of dyspepsia.

Evaluation of commercial immunoassays for detection of antibody against Helicobacter pylori in Thai dyspeptic patients

The performance of five immunoassays for detection of immunoglobulin G antibody against Helicobacter pylori in 191 dyspeptic patients was evaluated. The sensitivities, specificities, accuracies, positive predictive values, and negative predictive values ranged from 86.32 to 97.89%, 57.95 to 72.22%, 77.02 to 83.76%, 71.54 to 77.42%, and 83.33 to 96.23%, respectively. The immunoglobulin A test kit also gave a high sensitivity and negative predictive value (95.79 and 91.40%, respectively), while the specificity was relatively low (51.14%).

Cytotoxin associated gene A-positive Helicobacter pylori strains in dyspeptic pregnant women

OBJECTIVE

The aim of the present study was to compare the Helicobacter pylori (HP) seropositivity and cytotoxin associated gene A (cagA) status in pregnant women with dyspeptic complaints and pregnant women with no gastrointestinal symptoms.

STUDY DESIGN

Seventy-one consecutive pregnant women with gastrointestinal complaints and 72 age-matched pregnant women without any gastrointestinal symptoms or a history of gastrointestinal disease were included in the study. Demographic characteristics and H. pylori and cytotoxin associated gene A status of the groups were analysed.

RESULTS

The prevalence of H. pylori seropositivity was slightly but not significantly higher in patients with dyspeptic complaints compared to the controls (74.6% versus 63.8%, respectively, P > 0.05). The incidence of dyspeptic complaints were 53.5% in HP-seropositive and 40.9% in HP-seronegative women (P > 0.05). The prevalence of cytotoxin associated gene A positivity among H. pylori-seropositive women was significantly higher in dyspeptic pregnants compared to the controls (75.5% versus 45.7%, respectively, P = 0.002). Among HP-seropositive women, the incidence of dyspeptic complaints was significantly higher in cagA-positive patients compared to the cagA-negative ones (65.6% versus 34.2%, respectively, P = 0.002). When analysed according to the trimesters, the prevalence of cytotoxin associated gene A positivity among H. pylori-seropositive women was significantly higher in dyspeptic pregnants compared to the controls in the first trimester (68.0% versus 34.8%, respectively, P = 0.021).

CONCLUSION

Cytotoxin associated gene A-positive, virulent H. pylori strains were found to be more frequently associated with dyspeptic complaints in pregnant women.

High prevalence of seropositivity to a major allergen of Anisakis simplex, Ani s 1, in dyspeptic patients

Finding evidence of anisakidosis requires invasive methods. We have developed a serological assay based on the detection of an immunoglobulin E (IgE) specifically directed against Ani s 1 protein, a major parasite allergen of Anisakis simplex, which has shown a high level of accuracy in the diagnosis of anisakidosis. We used this tool to determine the prevalence of anti-Ani s 1 IgE in dyspeptic patients and to investigate if its seropositivity could be related to epidemiological factors other than raw fish consumption. A total of 174 dyspeptic patients who submitted to upper digestive tract endoscopy were studied. Specific IgE against Ani s 1 was determined by immunoblotting. Quantitative information on smoking, alcohol consumption, and fish consumption as well as a history of gastric surgery was recorded. Twenty-four (13.8%) patients were seropositive for Ani s 1 protein. The seroprevalence of anti-Ani s 1 IgE increased with age in patients who were less than 62 years old (P = 0.047). Seropositivity to Ani s 1 was associated with the consumption of fish in vinegar (P < 0.001), raw fish (P = 0.001), and smoked fish (P = 0.007). There was no relationship between anti-Ani s 1 IgE seropositivity and the number of cigarettes smoked (P = 0.098) or alcohol intake (P = 0.179). Five patients had undergone previous gastric surgery, and three of those patients were seropositive for Ani s 1 (P = 0.019). In multivariate analysis, the consumption of fish in vinegar (P = 0.006), raw fish (P = 0.017), and smoked fish (P = 0.002) and a history of gastric surgery (P = 0.005) were independent factors associated with anti-Ani s 1 IgE detection. In conclusion, at present, anisakidosis might frequently be underdiagnosed, and it might have a clinical role in patients with upper dyspeptic symptoms. Uncooked-fish ingestion and previous gastric surgery were associated with seropositivity for Ani s 1 protein.

Helicobacter pylori associated antigastric autoantibodies: role in Sjögren's syndrome gastritis

BACKGROUND

Previous studies have shown that Helicobacter pylori seroprevalence in Sjögren's syndrome is comparable with that of the general population. However, the origin of the chronic gastropathy associated with this syndrome and the role of local autoimmunity--possibly triggered by bacterial infection--in its pathogenesis remain unclear.

MATERIALS AND METHODS

We initially determined the prevalence of IgG anti H. pylori in dyspeptic subjects with and without Sjögren's syndrome. In subsets of both groups we then determined anti CagA and human tissue-tested anticanalicular/antifoveolar autoantibodies. We also compared activity, atrophy and Mucosa Associated Lymphoid Tissue (MALT) scores, as well as symptoms, before and after bacterial eradication.

RESULTS

Prevalence of H. pylori in Sjögren's syndrome patients was similar to controls: 31/54 (57%) vs. 93/150 (62%). Anti CagA prevalence was also similar in the two groups. Twenty weeks after H. pylori eradication, histological activity decreased in both groups, however, atrophy and MALT decreased significantly only in controls. Sixteen months after H. pylori eradication, 75% of Sjögren's syndrome patients still complained of dyspepsia compared with 13% of controls. Finally, antigastric autoantibodies were present in 29% of tested Sjögren's syndrome patients vs. 28% of controls.

CONCLUSIONS

H. pylori infection was equally prevalent among dyspeptic Sjögren's syndrome patients and dyspeptic controls. Likewise, there were no differences regarding anti CagA prevalence or antigastric autoantibodies among the two groups. The persistence of symptoms as well as of the lymphocytic infiltration and atrophy after H. pylori eradication in Sjögren's syndrome may underlie the 'endogenous' and still unknown nature of the gastropathy in this condition.

Helicobacter pylori increases the epithelial permeability to a food antigen in human gastric biopsies

AIMS

We have previously shown that H. pylori increases the passage of intact protein across the digestive epithelium, in vitro and in vivo in mice. The aim of this study was to test whether H. pylori can alter gastric permeability to a food-type antigen in humans.

METHODS

Antral and corpus gastric biopsies obtained from H. pylori-positive and H. pylori-negative patients suffering from nonulcer dyspepsia with normal esogastroduodenal endoscopy were mounted in adapted Ussing chambers to measure gastric permeability. Electrical resistance (R, an index of epithelial integrity) and fluxes of 14C-mannitol (JMan, a marker of paracellular permeability) and 3H-horseradish peroxidase (HRP, a test protein of antigen transport and processing) under intact (JHRPi) and degraded (JD) form, across the biopsies, were measured.

RESULTS

At the corpus level, biopsies obtained from H. pylori-positive patients, as compared to H. pylori-negative patients, presented significantly higher intact--but not degraded--HRP fluxes (JHRPi = 446 +/- 297 and 219 +/- 265 ng/h cm2, p < 0.05; JD = 4,247 +/- 3,884 and 3,575 +/- 2,594 ng/h x cm2, respectively), and an increase in paracellular permeability (Jman = 0.35 +/- 0.1 vs 0.24 +/- 0.08 micromol/h x cm2, p < 0.02, respectively). At the antrum level, a tendency to increased intact HRP fluxes in H. pylori-positive patients, as compared to H. pylori-negative patients, was observed (JHRPi = 284 +/- 250 vs 207 +/- 203 ng/h x cm2, p < 0.09), without modifications of paracellular permeability.

CONCLUSIONS

H. pylori infection increases absorption of an intact food antigen across the corpus gastric mucosa. This phenomenon may contribute to the maintenance of gastric inflammation and could play a role in the development of allergic sensitization to dietary antigens in susceptible individuals.

Intensity of inflammation, density of colonization and interleukin-8 response in the gastric mucosa of children infected with Helicobacter pylori

BACKGROUND

Few reports exist on inflammation and interleukin (IL)-8 response in H. pylori-infected children. The aim of this study was to determine the intensity of inflammation, density of colonization and magnitude of IL-8 response in children with and without H. pylori infection.

MATERIALS AND METHODS

We studied 45 children with dyspeptic symptoms, 21 infected with H. pylori and 24 without infection. Antrum and corpus gastric biopsies were obtained and studied for H. pylori infection with an immunofluorescence technique and for IL-8 with an immunohistochemical assay. Biopsy specimens were stained with hematoxilin and eosin and gastritis was graded according to the Sydney system. The magnitudes of the IL-8 response and H. pylori colonization were estimated microscopically with image analyzer software.

RESULTS

In H. pylori-infected children, mild mono-nuclear cell infiltration was found in 50%, and no neutrophils in 40% of cases. In the antrum but not in the corpus, the intensity of colonization correlated with neutrophil and mononuclear cell infiltration. The IL-8 response was significantly higher in the antrum (p <.05) and corpus (p <.02) of infected children, and was localized mainly in the surface and crypts of the epithelium. No correlation was found between the magnitude of the IL-8 response and the infiltration of either neutrophil or mononuclear cells.

CONCLUSIONS

In H. pylori-infected children, poor mononuclear and neutrophil infiltration was observed. Infection was associated with a higher IL-8 response by gastric epithelial cells. The density of colonization but not the IL-8 response correlated with neutrophil cell infiltration.

Incidence of anti-Helicobacter pylori and anti-CagA antibodies in rosacea patients

In recent years some authors have reported a possible correlation between Helicobacter pylori (Hp) and dermatological diseases such as rosacea. In this study we evaluated serum IgG and IgA anti-Hp in a group of 48 patients with rosacea. IgG antibodies were present in 81% of the rosacea patients with dyspepsia and 16% of the rosacea patients without dyspeptic symptoms. Serum IgG and IgA anti-Hp were detected by means of an enzymatic immunoabsorption test (enzyme-linked immunosorbent assay: ELISA). In addition, an evaluation of the anti-CagA antibodies by means of an immunoenzymatic method was carried out (ELISA, RADIM). IgA anti-Hp was present in 62% of patients with dyspepsia and in 6% of patients with no upper gastrointestinal symptoms. Anti-CagA antibodies were seen to be present in 75% of patients with both rosacea and gastric symptomatology, and were prevalent in patients affected by rosacea with papular symptoms in respect to rosacea with erythematous symptoms. The data that emerge from our case studies appear to confirm the hypothesis put forward by scientists who propose a correlation between the two clinical presentations rather than an inverse hypothesis of total independence.

Can the response to eradication therapy in Helicobacter pylori infection be predicted?

The failure to eradicate Helicobacter pylori infection with antibiotic therapy has become a major clinical problem, not entirely accounted for by either poor compliance or antibiotic resistance. Recognition that failed eradication is one outcome of the host-parasite relationship focuses attention on impaired host protection as a determinant of nonresponse to antibiotics. A secreted interleukin (IL)-4 whole blood assay was developed to determine whether persistent infection was contributed to by impaired cytokine responses. The blood assay was shown to correlate well with mucosal organ cultures. Significantly lower levels of IL-4 were detected in the whole blood assays in 11 subjects with failed eradication compared with subjects with successful eradication (P<0.05). This latter group underwent a Th1 to Th0 "switch", which appears to be important to successful eradication. Detection of subjects at risk for failing to eradicate infection with standard combination therapy, by virtue of low secreted IL-4 in whole blood cultures, may have clinical value.

Helicobacter pylori lipopolysaccharide in the IL-2 milieu activates lymphocytes from dyspeptic children

In this study, we assessed the proliferative response of peripheral blood mononuclear leukocytes (PBML) from 33 children/young adolescents with chronic dyspepsia, to H. pylori LPS in the presence and absence of IL-2 as a T cell growth factor. A rapid urease test (RUT) and a presence of Helicobacter-like organisms (HLO) in the biopsy specimens allowed us to distinguish RUT/HLO-positive (17/33) and -negative (16/33) patients. H. pylori LPS alone induced a proliferation of PBML from 4 out of 33 dyspeptic patients. IL-2 increased the prevalence of the response to LPS to 59% and 74% of RUT/HLO-positive and -negative patients, respectively. PBML from RUT/HLO-positive patients responded significantly less intensively to H. pylori LPS in the presence of IL-2, to IL-2 alone and to H. pylori LPS+IL-2. However, there was no difference in PHA-driven proliferation of PBML from the patients of those two groups. A negative correlation between the responsiveness to H. pylori LPS of PBML and occurrence of type B inflammation in gastric mucosa was demonstrated. The results suggest a contribution of H. pylori LPS to an outcome of H. pylori infection. It is speculated that H. pylori LPS by an activation of immunocompetent cells may reduce gastric inflammation, decrease bacterial load and prolong H. pylori infection.

Patients with unstable angina pectoris present increased humoral response against Helicobacter pylori in comparison with patients with aggravated dyspepsia

A role of autoimmune process and its link with bacterial infections in initiation or aggravation of atherosclerosis symptoms has been suggested. Antigenic mimicry and cross-reactivity of circulating antibodies have been indicated as some major factors in this process. In this study, the prevalence and titers of IgG and IgA antibodies reacting with glycine extract of H. pylori surface antigens were determined immunoenzymatically (ELISA) in the group of patients with unstable ischaemic heart disease and in patients with aggravated dyspepsia. Our results reveal that elevated titers of IgG anti-H. pylori are more typical for cardiac patients and lower prevalence of IgA anti-H. pylori--for those with aggravated dyspepsia. This supports the hypothesis that intensed humoral response in immunoglobulins class G against some bacterial antigens may play a role in the aggravation of symptoms of coronary atherosclerosis.

Clinical and pathological implications of IgG antibody responses to Helicobacter pylori and its virulence factors in non-ulcer dyspepsia

AIM

To determine whether pre-treatment antibody response to Helicobacter pylori virulence factors predicts eradication success and symptom relief 12 months after triple therapy in non-ulcer dyspepsia.

METHODS

H. pylori-positive patients with non-ulcer dyspepsia received 1-week omeprazole-based triple therapy, or omeprazole plus placebos. Symptoms were assessed using a validated Likert scale. Gastric biopsies taken before and 12 months after treatment were used for histological examination. Pre-treatment blood samples were used for the detection of anti-H. pylori immunoglobulin G (IgG) antibodies, and specific IgG antibodies to 19.5-, 26.5-, 30-, 35-, 89- (VacA) and 116-kDa (CagA) antigens of H. pylori.

RESULTS

IgG antibodies to the six antigens were detected in 62%, 96%, 88%, 47%, 54% and 78% of patients, respectively. The presence of antibody to 19.5-, 26.5- or 30-kDa antigen was associated with an increased anti-H. pylori IgG absorbance index. IgG absorbance indices were greater in those with H. pylori eradication (vs. persistent infection). The prevalence of antibodies to the six antigens was not significantly different between those with symptom relief vs. those without. The 19.5-kDa antigen (P = 0.018) and VacA (P = 0.001) were independent risk factors for body gastritis.

CONCLUSIONS

An increased pre-treatment anti-H. pylori IgG absorbance index may be a useful predictor of the success of eradication therapy. Although the 19.5-kDa antigen and VacA were associated with body gastritis, none of the six antigens tested predicted symptom relief after triple therapy.

[Assessment of the response of peripheral blood mononuclear leukocytes on Helicobacter pylori infection in children]

In the study the proliferative response of peripheral blood mononuclear leukocytes (PBML) from children with chronic dyspepsia (chr. d) to H.p. antigens was investigated. From 38 children aged 7-18, with chr. d., blood was collected just before upper GI endoscopy. Twenty one patients were found to be H.p. (+). PBML were used for the cultures and were stimulated with heat-killed H.p. G27 bacteria, heated and unheated glycine extract (GE) of H.p. G27 or with H.p. LPS containing Lewis X and Lewis Y determinants, in the presence or absence IL-2. The cell proliferation was estimated on the basis of [3H] - thymidine incorporation. In the cultures, the phenotype of responding cells was determined by an EIA with monoclonal antibody to human CD3, CD4 and CD8. PBML from patients H.p. (-), responded to killed H.p. bacteria and to heated GE more frequently and more intensively than PBML from the H.p.(+). IL-2 enhanced PBML response to these antigens. Unheated GE did not induce PBML proliferation even in the cultures with IL-2. LPS alone induced proliferation of PBML from 3 patients (2 H.p. - and 1 H.p.+). However, in the presence of IL-2, LPS induced proliferation of PBML from 15 patients. In the cultures of PBML stimulated with whole bacteria or heated EG, T cells dominated. In the cultures of PBML from H.p. (+) we found a higher percentage of CD8 cells in comparison with the cultures of PBML from H.p. (-). Data demonstrate a significant variation in the response of PBML from dyspeptic children to H.p. antigens.

Peripheral blood lymphocyte population in children infected with Helicobacter pylori

PURPOSE

Helicobacter pylori infection in children is associated with a chronic inflammatory process of gastric and duodenal mucosa, which may have a various clinical course ranging from asymptomatic and chronic inflammatory condition to gastric ulceration. The immune system may contribute especially to chronic gastric mucosa inflammation. The aim of our study was to assess the levels of peripheral blood T (CD3+, CD4+, CD8+) and B lymphocyte subpopulation (CD19+) in children with Helicobacter pylori infection and to evaluate their relation to degree of antrum mucosa inflammation.

MATERIAL AND METHODS

The study was performed in 32 children aged 7-18 years, hospitalized due to dyspeptic symptoms. The endoscopic examination of upper gastrointestinal tract was performed and gastric and duodenal mucosa was estimated in all patients. The endoscopic and histological evaluation of gastric mucosa was performed according to the Sydney System [4]. The urease test (CLO-test-H. pylori) was made to estimate the severity of the infection.

RESULTS

Moderate antrum mucosa inflammation was found in 41.2% of the examined. The highest percentage of children (58.8%) presented marked inflammation. No mild inflammation was found in children examined.

CONCLUSIONS

No correlation was found between lymphocyte levels and the degree of the inflammatory changes in antrum mucosa. The evaluation of peripheral blood lymphocytes performed in children with Helicobacter pylori infection suggests that T lymphocytes may play a predominant role in this infection.

p53 and Ki-67 expression in epithelial gastric dysplasia and in gastric cancer

BACKGROUND

The aim of this study was to examine p53 and Ki-67 expression in relation to high grade dysplasia (HGD) clinical behaviour.

METHODS

A retrospective, cross sectional study was conducted on mucosal biopsies from the stomach of 38 consecutive cases of HGD (25 males, average age: 57.5). The studied samples are represented by gastric biopsies obtained in course of gastroscopy for dyspepsia (at least 8 biopsies). HGD diagnosis was done by experienced pathologists (MC, DG) according to Goldstein's criteria. There were 12 non-dysplastic controls (7 males, average age: 49.4). The immunohistochemical study has been led with the utilization of a p53-antibody. For the cell proliferation assay, the sections were incubated with the MM1 monoclonal antibody. The clinical outcome subdivision of HGD was effected using the criteria of Rugge et al. For the classification of gastric cancer (GC): UICC TNM.

RESULTS

p53 positivity has been evidenced in 65.5% of cases, while hyperproliferation in 100% of cases. That independently of the clinical behaviour.

CONCLUSIONS

p53 positivity has been found only in part of the HGD cases and moreover a number of HGD with low or absent p53 scores has been found associated with high proliferation indices independently of the clinical evolution. This dissociation of cell kinetics and p53 expression suggests that other genetic events contributing to unregulate cell proliferation may occur in these lesions.

Major differences in the IgG subclass response to Helicobacter pylori in the first and third worlds

BACKGROUND

Studies in developed countries would suggest that the immune response to Helicobacter pylori infection is a T helper cell I predominant response. Unlike subjects from developed countries, those resident in developing countries are subject to infection with a myriad of gastrointestinal pathogens from early in life. Given that H. pylori is acquired early in life, such infections may alter the immune response to H. pylori. The aim of this study was to compare the immune response to H. pylori in subjects from developed and developing countries.

METHODS

Using a previously validated IgG subclass ELISA, the H. pylori specific IgG I/IgG2 subclass ratio (a marker of the T helper cell response) in 58 adult and 21 paediatric symptomatic H. pylori positive Sowetan subjects was compared with that in 64 Australian and 45 German symptomatic H. pylori positive subjects.

RESULTS

An IgGI predominant response (IgG1/IgG2 ratio >1) was observed in 81% of Sowetan adults and 90% of children compared with 4.7% of Australians and 4.4% of Germans. The IgG1/IgG2 ratio was significantly higher in Sowetans compared with Australians and Germans (P < 0.001). In Australian and German subjects the IgG1/IgG2 ratio was significantly higher in NUD compared with DU. No significant difference was observed between NUD and other disease states in Sowetans.

CONCLUSIONS

This study is the first to provide evidence that the host immune response to H. pylori infection in an African population differs to that observed in subjects from developed countries. Further studies are required to determine if this occurs in other developing countries.

Optimal serological tests for the detection of Helicobacter pylori infection in the Chinese population

BACKGROUND

Numerous serological tests for the detection of Helicobacter pylori infection have been developed. However, many perform poorly when evaluated in the Chinese population.

AIM

To search for optimal serological tests for the detection of H. pylori infection in Chinese patients.

METHODS

Consecutive dyspeptic patients referred for upper endoscopy were recruited. During endoscopy, gastric biopsies were taken for the CLOtest and histological examination. Patients were then given a 13C-urea breath test. Sera were used to test for H. pylori infection, employing three commercial enzyme-linked immunosorbent assay kits (pylori DTect, HP IgG and GAP IgG). Results were compared with the gold standard defined by the CLOtest, histology and 13C-urea breath test.

RESULTS

Among the 142 patients (47 male, 95 female; mean age, 49 years) recruited, 81 (57%) were H. pylori-positive, 57 (40%) were H. pylori-negative and four (3%) were defined to be indeterminate. Using a self-defined cut-off value after calculation, the best accuracies for the pylori DTect, HP IgG and GAP IgG tests were 97%, 91% and 80%, respectively.

CONCLUSIONS

The pylori DTect test is an optimal serological test for the detection of H. pylori infection in Hong Kong Chinese patients. The HP IgG test may be used as an alternative.

Expression of surfactant protein D in the human gastric mucosa and during Helicobacter pylori infection

Helicobacter pylori establishes persistent infection of gastric mucosa with diverse clinical outcomes. The innate immune molecule surfactant protein D (SP-D) binds selectively to microorganisms, inducing aggregation and phagocytosis. In this study, we demonstrated the expression of SP-D in gastric mucosa by reverse transcription-PCR and immunohistochemical analysis. SP-D is present at the luminal surface and within the gastric pits, with maximal expression at the surface. Levels of expression are significantly increased in H. pylori-associated gastritis compared to those in the normal mucosa. Immunofluorescence microscopy was used to demonstrate binding and agglutination of H. pylori by SP-D in a lectin-specific manner. These activities resulted in a 50% reduction in the motility of H. pylori, as judged on the basis of curvilinear velocity measured by using a Hobson BacTracker. Lipopolysaccharides extracted from three H. pylori strains were shown to bind SP-D in a concentration-dependent manner, and there was marked variation in the avidity of binding among the strains. SP-D may therefore play a significant role in the innate immune response to H. pylori infection.

Novel antigens of Helicobacter pylori correspond to ulcer-related antibody pattern of sera from infected patients

Recently, we reported that the patterns of antibodies to Helicobacter pylori protein antigens in serum may be useful for screening patients at high risk for ulcers (P. Aucher et al., J. Clin. Microbiol. 36:931-936, 1998). Here we report the identification, by a combination of electrophoretic, immunochemical, and protein sequencing methods, of five antigens that correspond to this antibody pattern: groEL, catalase A, flagellin A, beta-ketoacyl-acyl carrier protein synthase I (beta-ketoacyl-ACP S), and peptidyl prolyl cis-trans isomerase (PPiase). Beta-Ketoacyl-ACP S and PPiase are reported for the first time as antigens of diagnostic interest in infections by H. pylori. The antigenicity of the five antigens, together with those of CagA and VacA, was tested in an immunoblot assay with water-soluble protein extracts from two H. pylori pathogenic strains (HP 141 and ATCC 43579) and panels of sera from H. pylori-positive patients with gastroduodenal ulcers (GDU), nonulcer dyspepsia (NUD), as well as sera from H. pylori-negative healthy volunteers. For catalase A, groEL, and flagellin A antigens, no overall statistically important values were found making it possible to discriminate between patients with GDU and NUD. For both H. pylori strains, the mean performance indices (MPI) presenting percentages of correctly classified patients with GDU and NUD showed that the most significant antibody patterns were as follows: anti-VacA + anti-beta-ketoacyl-ACP S (MPI = 76.1), anti-VacA + anti-PPiase (MPI = 71.8), and anti-CagA + anti-VacA + anti-beta-ketoacyl-ACP S (MPI = 70.5). Antibody patterns detected with these antigen profiles may therefore be useful in developing a diagnostic test designed to predict the clinical severity of the H. pylori infection within the adult population of France.

Variation in serum pepsinogens with severity and topography of Helicobacter pylori-associated chronic gastritis in dyspeptic patients referred for endoscopy

BACKGROUND

It has long been recognised that specific patterns of gastritis are linked with different gastroduodenal diseases and that serum pepsinogens vary with the histological state of the gastric mucosa. With the discovery of the role of Helicobacter pylori in chronic gastritis and the availability of noninvasive tests for H. pylori infection, individuals with H. pylori gastritis can now be identified without endoscopic biopsy. However, without a knowledge of the pattern and severity of gastritis it is impossible to predict the likelihood of significant associated gastroduodenal pathology.

AIMS

The aim of this study was to evaluate the diagnostic potential of serum pepsinogens I and II in predicting the topography and severity of gastritis in H. pylori-infected dyspeptic patients attending for endoscopy.

METHODS

Fasting serum was obtained from consecutive dyspeptic patients attending for endoscopy, and pairs of gastric biopsies obtained from the mid-body and antrum. Gastritis was graded according to the Sydney System, and serum pepsinogen levels determined by radio-immunoassay.

RESULTS

Sixty-nine dyspeptic patients were studied (mean age: 49.6 years) of whom 34 had H. pylori-associated chronic gastritis (Hp-gastritis) - antral predominant gastritis (APG) in 41.2%, pangastritis (PAN) in 52.9%, and corpus predominant (CPG) in 5.9%. Serum pepsinogen II levels were significantly higher, and the serum pepsinogen I : II ratio significantly lower, in the H. pylori positive group than in other groups. Within the Hp-gastritis group, there was a step-wise decrease in serum pepsinogen I levels with progression from APG through PAN to CPG pattern (a cut-off value of > or = 100 ng/ml would have identified APG with a positive predictive value of 77%, though with low sensitivity). Within the Hp-gastritis group, serum pepsinogen I and II levels were correlated with antral chronic inflammation score and serum pepsinogen II levels also with antral activity score. Serum pepsinogen I and the pepsinogen I : II ratio were lowest in severe gastric corpus atrophy.

CONCLUSION

In dyspeptic patients known to be infected with H. pylori, serum pepsinogen values provide an assessment of the overall topography of gastritis, the severity of antral inflammation and the presence of severe corpus atrophy.

H. pylori and functional dyspepsia: increased serum antibodies as an independent risk factor?

The relationship between H. pylori and functional dyspepsia is controversial. Hypothesizing that subjects with a more intense immune response to H. pylori (and hence higher antibody titers) would be at greater risk of dyspepsia, we aimed to identify risk factors for the development of dyspeptic symptoms. In all, 491 healthy blood donors with no history of peptic ulceration and 74 consecutive patients with a confirmed diagnosis of functional dyspepsia were studied. Symptoms and potential risk factors [nonsteroidal antiinflammatory drugs (NSAIDs), alcohol, and smoking] were measured by a validated questionnaire. H. pylori status was determined by IgG antibodies using a validated ELISA test with a cutoff titer for a positive serology of 10 units/ml. Logistic regression analysis assessed the association between risk factors and dyspepsia. Among blood donors, 21% (95% CI 17.6-24.8) reported dyspepsia (pain localized to the upper abdomen); 7.7% (95% CI 5.5-10.4) had frequent dyspepsia (>6 times in the prior year). The age-adjusted prevalence of H. pylori was not significantly different in blood donors with (39.5%, 95% CI 24.0-56.6) and without frequent dyspepsia (34.2%, 95% CI 29.8-38.36), but was significantly greater in patients with functional dyspepsia (68.8%, 95% CI 57.3-77.9). In the combined study population of blood donors and patients with functional dyspepsia, logistic regression adjusting for age identified the following independent risk factors for frequent dyspepsia: high serum antibody levels against H. pylori (OR for IgG titer >50 units/ml vs H. pylori titers 11-50 units/ml 4.6, 95% CI 2.7-7.8) and consumption of standard NSAIDs (OR 2.4,95% CI 1.3-4.5). In contrast, alcohol (OR 0.6, 95% CI 0.3-1.0), smoking (OR 1.5, 95% CI 1.0-2.3) or positive H. pylori serology with titers < or = 50 units/ml (OR 1.6, 95% CI 0.8-2.9) were not associated with frequent dyspepsia. In conclusion, in a subgroup of H. pylori-infected subjects who have high antibody titers, H. pylori appears to be associated with functional dyspepsia.

Seroprevalence of Helicobacter pylori among the diabetic population in Bangladesh: a comparative serological study on the newly diagnosed and older diabetics

This prospective study was designed to find out the prevalence of H. pylori infection among the diabetic population in Bangladesh with a comparison between the newly diagnosed and older diabetics. For this study 520 diabetic patients: 152 (29%) newly diagnosed and 368 (71%) older diabetics of both sexes (250 male, 270 female) with a mean age of 58.5 +/- 12.04 years (range 10-70 years), were selected randomly from out and in-patient departments of BIRDEM, Dhaka. Mean fasting and 2 hours post load blood glucose level of the studied population was 10.53 +/- 4.08 mmol/L and 18.35 +/- 9.44 mmol/L respectively. The mean duration of the newly diagnosed diabetics was 0.44 +/- 0.35 years (range 2 days-1 year) and 6.78 +/- 5.45 (range 1-30) years for the older diabetics. H. pylori infection was defined as a true positive ELISA test result of > 1.5 standard deviation above the cut-off values of 15 AU/ml for adults and 10 AU/ml for children for anti H. pylori IgG. Of the studied population 441 (84.8%)--132 newly diagnosed and 309 (83.96%) older diabetics were seropositive for H. pylori infection. No significant differences were observed between the newly diagnosed and older diabetics (86.84% Vs 83.96%; p > 0.05).

Influence of smoking and alcohol on gastric chemokine mRNA expression in patients with Helicobacter pylori infection

AIM

Chemokines that play a primary role in active inflammation are increased in gastric mucosa infected with Helicobacter pylori. Cigarette smoking increases the risk of peptic ulcer disease and gastric cancer, whereas alcohol might exert an antibacterial role. The aim of this study was to examine the association between smoking or alcohol consumption and mucosal chemokine mRNA expression in H pylori associated gastritis.

METHODS

Gastric biopsy specimens were obtained from 46 patients with dyspepsia who were infected with H pylori, and total RNA was extracted. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was performed to quantify the mRNA expression of three C-X-C chemokines (interleukin 8 (IL-8), growth related oncogene alpha (GRO alpha), epithelial neutrophil activating protein 78 (ENA-78)) and two C-C chemokines (regulated on activation normal T cell expressed and secreted (RANTES) and monocyte chemotactic protein 1 (MCP-1)).

RESULTS

GRO alpha and ENA-78 mRNA expression was significantly increased (p < 0.05) in 22 smokers compared with 24 non-smokers; however, no difference was seen in the expression of IL-8, RANTES, and MCP-1 mRNA. No differences were observed in chemokine mRNA expression in relation to alcohol consumption.

CONCLUSIONS

The increased C-X-C chemokine mRNA expression seen in smokers might play a role in inducing enhanced inflammatory activity in gastritis and the consequent severe diseases associated with H pylori infection.

Genetic diversity in the Helicobacter pylori cag pathogenicity island and effect on expression of anti-CagA serum antibody in UK patients with dyspepsia

AIMS

To investigate variation within the cag pathogenicity island (PAI) of Helicobacter pylori isolated from patients with dyspepsia in mid-Essex, and to evaluate the effect on expression of anti-CagA antibody.

METHODS

Sixty two isolates of H pylori cultured from gastric biopsies were screened by specific PCR assays for the presence of cagA and other gene markers (cagD and cagE, and virD4) in the cag PAI. An enzyme linked immunosorbent assay (ELISA) kit (Viva Diagnostica helicobacter p120) was used to test for anti-CagA IgG antibody in matching sera. Isolates were also genotyped by vacuolating cytotoxin polymerase chain reaction (PCR) analysis, and tested for absence of the complete cag PAI (empty site PCR assay).

RESULTS

Forty one of the H pylori isolates had a cag PAI containing cagA. One strain had no cagA but other cag PAI loci were present, whereas the remaining 20 strains had no detectable cag PAI markers. Anti-CagA IgG antibody was detected in 34 sera by the ELISA assay, and when compared with the cag PAI genotype of the infecting strain, accuracy, sensitivity, and specificity were 92%, 87%, and 100%, respectively. The seven discrepant or borderline strains in the ELISA were all vacA s1 but differed in other genotypic markers.

CONCLUSIONS

The cag PAI was widely distributed in H pylori from patients with dyspepsia in mid-Essex who had different gastric pathologies. Infection with a strain having an uninterrupted cag PAI was associated with the presence of anti-CagA antibody in most patients. Discrepant ELISA results, mostly for elderly patients with duodenal ulcers, were attributed to cagA associated variation, particularly to the presence of mixed cagA+/cagA- cell variants in the infecting strain population. Tests for anti-CagA serum antibody were unreliable for predicting severity of clinical disease associated with H pylori infection in this series of patients.

A potential double role of anti-Lewis X antibodies in Helicobacter pylori-associated gastroduodenal diseases

In this study, we found Lewis X (Le(x)) determinants on 68% of Helicobacter pylori isolates from patients with chronic gastroduodenal diseases. Anti-Le(x) IgG were detected more frequently in the sera from dyspeptic children and adults (45 and 46%), with or without proved (culture) H. pylori infection, than in the sera from healthy individuals (14% and 25%). In contrast, the prevalence of anti-Le(x) IgM was higher in the groups of healthy individuals than in the groups of dyspeptic patients. Moreover, anti-Le(x) monoclonal antibody of IgM class enhanced the uptake of Le(x)(+) but not Le(x)(-) H. pylori isolates by phagocytes. In the sera from some dyspeptic patients, we detected Le(x)-anti-Le(x) IgG immune complexes (Le(x) ICs). There was a great difference between children and adults as regards the presence of Le(x) ICs. The immune complexes were found in the sera from nine out of 29 (27%) H. pylori-infected and three out of eight (37%) uninfected adult dyspeptic patients. In comparison, Le(x)-anti-Le(x) IgG ICs were detected only for two out of 18 (11%) H. pylori-infected children. Le(x) ICs were not found in the sera from healthy individuals. Our results suggest that anti-Le(x) IgM may play a protective role in H. pylori infections. In contrast, anti-Le(x) IgG and particularly Le(x)-anti-Le(x) IgG ICs might contribute to the pathogenesis of chronic H. pylori infections.

Increased gastric epithelial cell apoptosis associated with colonization with cagA + Helicobacter pylori strains

Gastric colonization by Helicobacter pylori is a risk factor for noncardia gastric cancer. The association between H. pylori and cancer may be attributable to increased epithelial cell turnover, possibly related to antigastric antibodies. Two previous studies reported a disproportionate increase in proliferation relative to apoptosis in patients with H. pylori strains expressing the virulence-related cagA gene. This has led to the hypothesis that an abrogation of apoptosis by cagA-positive strains may promote neoplasia. We, therefore, examined the effect of H. pylori on gastric epithelial proliferation, apoptosis, and the presence of serum antiparietal cell antibodies in a large prospective study. Proliferation and apoptosis were evaluated "blindly" using validated immunohistochemical methods in two antral and two gastric corpus biopsies from 60 patients with nonulcer dyspepsia, and results were correlated with the presence of serum antiparietal cell antibodies. H. pylori colonization was assessed by histology, biopsy urease test, and serology. Proliferation was increased 2-fold in both antrum and corpus in H. pylori-positive patients, was not related to H. pylori cagA status, and was positively correlated with histological gastritis. Apoptosis was increased in the antrum and body only in patients with cagA-positive H. pylori strains. Antiparietal cell antibodies were not more prevalent in H. pylori colonization, and their presence was inversely related to epithelial apoptosis scores we therefore conclude that in patients with nonulcer dyspepsia, H. pylori carriage is associated with increased proliferation. Futhermore the cag pathogenicity island is associated with increased apoptosis. Our results do not support the hypothesis that there is a relative deficiency of gastric epithelial cell apoptosis associated with the carriage of cagA-positive strains. Host factors may be more important than bacterial products in determining the long-term outcome of H. pylori colonization.