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.