Prevalence of CagA and VacA antibodies in children with Helicobacter pylori-associated peptic ulcer compared to prevalence in pediatric patients with active or nonactive chronic gastritis

VacA and CagA serological responses were detected in pediatric patients: 44 and 56%, respectively, in peptic ulcer (PU) patients, 33.3 and 44.4% in active chronic gastritis (ACG) patients, and 23.2 and 39.2% in non-ACG patients. Higher seroprevalence to CagA+VacA and to CagA+VacA+35-kDa antigen was found among PU patients. However, a low level of sensitivity and specificity was found for indirect detection of PU patients.     

Serum CagA antibodies in asymptomatic subjects and patients with peptic ulcer: lack of correlation of IgG antibody in patients with peptic ulcer or asymptomatic Helicobacter pylori gastritis.

AIM/BACKGROUND: Several studies have suggested that Helicobacter pylori which express CagA may be more virulent than those that do not, but limited populations have been studied to date. The aim of this study was to confirm and extend the association of CagA positive H pylori strains in a different geographical area and to a large, well defined patient population. METHOD: A validated ELISA for serum IgG to CagA was used to investigate the prevalence of CagA seropositivity in 100 patients with peptic ulcer compared with 77 with H pylori infection without ulcer disease in a North American population. The extent of antral and corpus inflammation and H pylori density in relation to CagA seropositivity in 40 subjects with H pylori infection were assessed semiquanitatively. All studies were carried out in a coded and blinded manner. RESULTS: The prevalence of serum IgG CagA antibodies was higher in H pylori infected patients with ulcer (59%) compared with healthy H pylori infected volunteers (44%), but the difference was not significant. In contrast, the titre of serum IgG anti-CagA antibodies was higher among the seropositive subjects without ulcer disease, but again the difference was not significant. Comparison of histological features between asymptomatic individuals with H pylori infection in relation to CagA IgG antibody status revealed no differences in infiltration with acute inflammatory cells, H pylori density, or gastritis index. There was no relation evident between the degree of polymorphonuclear cell infiltration and the serum IgG antibody titre to CagA. Mononuclear cell infiltration in the antrum, but not the corpus, was greater in those with CagA IgG compared with those without (median score 5 v 3). CONCLUSIONS: A right association between the presence or titre of serum IgG to CagA and peptic ulcer disease, greater H pylori density or infiltration of the mucosa with acute inflammatory cells could not confirmed in a North American population. Perhaps geographical differences in the prevalence of circulating H pylori strains are responsible for the discrepant results reported.     

Heterogeneity in susceptibility to metronidazole among Helicobacter pylori isolates from patients with gastritis or peptic ulcer disease.

Combination therapies that include metronidazole (MTZ) are the most successful therapies used in eradicating Helicobacter pylori. In this study, the prevalence and the relevance of heterogeneity in susceptibility to MTZ among H. pylori populations of 156 patients were evaluated. The results of this study show that 37 patients (24%) were infected with MTZ-resistant H. pylori (MIC > or = 8 micrograms/ml). Furthermore, 33% (52 of 156) of the patients were found to be infected with H. pylori populations heterogeneous for their susceptibility to MTZ. The reassessment of the MICs of MTZ for these 52 H. pylori populations revealed MTZ resistance in 28 of them, increasing the number of MTZ-resistant H. pylori populations among the 156 patients to 65 (42%). Out of 20 isolates, 2 (10%) heterogeneous in their susceptibility to MTZ also appeared to be heterogeneous at the genome level as determined by randomly amplified polymorphic DNA fingerprinting. In conclusion, the results show the limitations and risk of possible misinterpretations when only a single colony, picked from the primary H. pylori populations isolated from patients, is analyzed for its susceptibility to MTZ.     

Campylobacter pylori is associated with chronic gastritis but not with active peptic ulcer disease

Campylobacter pylori is supposed to be involved in the pathogenesis of gastroduodenal peptic ulcer diseases and chronic gastritis. In order to study whether the Campylobacter pylori in the stomach of peptic ulcer patients is related to ulcer itself or to a co-existing chronic gastritis, we examined the frequency of the bacteria in Giemsa stained histological sections of biopsy specimens from a series of patients with active peptic ulcer and from series of non-ulcer control subjects. We found no difference in the frequency of Campylobacter- positive cases between ulcer patients and non-ulcer controls when the comparison was done within the same category of chronic gastritis; e.g., within the category of chronic superficial gastritis 74% and 78% of cases showed the bacteria in antral biopsies from ulcer patients and from non-ulcer controls, respectively. In both ulcer patients and control subjects, in similar way in both antral and body mucosa, the Campylobacter pylori was strongly associated with chronic superficial gastritis but was more weakly associated with chronic atrophic gastritis, and the bacteria were only occasionally seen in normal mucosa. We conclude that Campylobacter pylori is associated with chronic gastritis in peptic ulcer patients but is not related to active ulcer.     

Detection of Helicobacter pylori DNA in peripheral blood from patients with peptic ulcer or gastritis

Cases of Helicobacter bacteremia have been reported from time to time. Helicobacter pylori is the most important representative of Helicobacterium, yet whether it can result in bacteremia has rarely been studied. In this study, we examined H. pylori DNA in peripheral blood and gastric mucosa of patients with peptic ulcer or chronic gastritis by polymerase chain reaction (PCR). We found H. pylori DNA in 15 of 20 gastric samples, and 9 of these specimens were positive for H. pylori culture. H. pylori DNA amplified by PCR was positive in the peripheral blood of three patients, who all had duodenal ulcers. Gastric biopsy specimens from these three patients were all positive for H. pylori genes and H. pylori was isolated from these specimens. After the 16S rRNA gene sequences of three specimens from the same patient were obtained, we found that they were identical, which suggested that they are the same strain. Our findings suggest that H. pylori exists not only in gastric mucosa but also in peripheral blood, and it is possible that H. pylori can result in bacteremia.     

Association of Helicobacter pylori with gastritis and peptic ulcer diseases

The occurrence of Helicobacter pylori(H.pylori) and its relationship with gastric mucosa were studied by light and electron microscopy and culture of biopsy specimens from gastric mucosa of 160 patients with upper gastrointestinal symptoms. H. pylori were present in 96.6% of patients with active chronic gastritis, 100% of patients with duodenal ulcer and 76.9% of patients with gastric ulcer, while present in only 6.3% of individuals with histologically normal gastric mucosa. The bacteria colonized the antral mucosa more frequently than the body or than the duodenal cap mucosa. The bacteria were rarely seen in the intestinalized epithelium per se, but there was no significant difference in prevalence of H. pylori between gastritis with intestinal metaplasia and gastritis without intestinal metaplasia. H. pylori could be seen in close association with the surface of gastric epithelial cells below the mucus layer without evidence of intracellular parasitism, All of the strains tested were susceptible to penicillin, erythromycin, and most of them susceptible to tinidazole and bismuth salts. It is concluded that H. pylori are highly associated with gastritis and peptic ulcer diseases and its prevalence rates in patients with those diseases is higher than in developed countries. This strong association of H. pylori infection with gastritis and peptic ulcer diseases suggest a possible etiologic role for the bacterium in those diseases.     

Helicobacter pylori in patho- and morphogenesis of chronic gastritis and peptic ulcer

Review of the literature on the role of Helicobacter pylori (HP) in the patho- and morphogenesis of chronic gastritis (CG) type B, gastric ulcer (GU) and duodenal ulcer (DU) is presented. Various hypotheses of pathogenetic effect of HP, histologic and ultrastructural characteristics of changes in the gastric and duodenal mucosa in HP infection are presented. The majority of authors consider HP as a possible pathogenic factor in CG type B, GU and DU. However, there are works in which HP is regarded as a saprophyte or a secondary infection. This indicates a necessity of further studies.     

Clinico-morphologic characteristics of reflux gastritis in patients with peptic ulcer before and after surgical intervention

Experimental and clinical studies convincingly indicate that duodenal-gastric reflux may provoke the development of reflux gastritis with a characteristic clinico-morphological complex. However, the clinical picture of reflux gastritis in patients with stomach ulcer is not always typical, is frequently masked by the underlying disease and therefore is difficult for diagnosis. The necessity of the use of the laboratory and instrumental methods arises, with an obligatory histological examination. Morphological studies indicate the existence of certain characteristic signs of reflux gastritis, the detection of which makes this diagnosis valid.