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BackgroundHelicobacter pylori infection is one of the most common infections worldwide and is associated with gastric cancer and peptic ulcer. Bacterial virulence factors such as CagA have been shown to increase the risk of both diseases. Studies have suggested a causal role for CagA EPIYA polymorphisms in gastric carcinogenesis, and it has been shown to be geographically diverse. We studied associations between H. pylori CagA EPIYA patterns and gastric cancer and duodenal ulcer, in an ethnically admixed Western population from Brazil. CagA EPIYA was determined by PCR and confirmed by sequencing. A total of 436 patients were included, being 188 with gastric cancer, 112 with duodenal ulcer and 136 with gastritis.ResultsThe number of EPIYA C segments was significantly associated with the increased risk of gastric carcinoma (OR = 3.08, 95% CI = 1.74 to 5.45, p < 10-3) even after adjustment for age and gender. Higher number of EPIYA C segments was also associated with gastric atrophy (p = 0.04) and intestinal metaplasia (p = 0.007). Furthermore, patients infected by cagA strains possessing more than one EPIYA C segment showed decreased serum levels of pepsinogen I in comparison with those infected by strains containing one or less EPIYA C repeat. Otherwise, the number of EPIYA C segments did not associate with duodenal ulcer.ConclusionsOur results demonstrate that infection with H. pylori strains harbouring more than one CagA EPIYA C motif was clearly associated with gastric cancer, but not with duodenal ulcer.Higher number of EPIYA C segments was also associated with gastric precancerous lesions as demonstrated by histological gastric atrophic and metaplastic changes and decreased serum levels of pepsinogen I.

ObjectiveIron deficiency (ID) and iron deficiency anaemia (IDA) are global major public health problems, particularly in developing countries. Whilst an association between H. pylori infection and ID/IDA has been proposed in the literature, currently there is no consensus. We studied the effects of H. pylori infection on ID/IDA in a cohort of children undergoing upper gastrointestinal endoscopy for upper abdominal pain in two developing and one developed country.MethodsIn total 311 children (mean age 10.7±3.2 years) from Latin America - Belo Horizonte/Brazil (n = 125), Santiago/Chile (n = 105) - and London/UK (n = 81), were studied. Gastric and duodenal biopsies were obtained for evaluation of histology and H. pylori status and blood samples for parameters of ID/IDA.ResultsThe prevalence of H. pylori infection was 27.7% being significantly higher (p<0.001) in Latin America (35%) than in UK (7%). Multiple linear regression models revealed H. pylori infection as a significant predictor of low ferritin and haemoglobin concentrations in children from Latin-America. A negative correlation was observed between MCV (r = −0.26; p = 0.01) and MCH (r = −0.27; p = 0.01) values and the degree of antral chronic inflammation, and between MCH and the degree of corpus chronic (r = −0.29, p = 0.008) and active (r = −0.27, p = 0.002) inflammation.ConclusionsThis study demonstrates that H. pylori infection in children influences the serum ferritin and haemoglobin concentrations, markers of early depletion of iron stores and anaemia respectively.

SummaryWe evaluated the role of the family in the transmission of Helicobacter pylori infection in preschool-aged children from a rural district in the State of Minas Gerais, Brazil. Sixty-six families (66 index children, 63 mothers, 60 fathers and 134 siblings), defined as at least one parent living in the same household with at least one offspring up to 8 years old, were studied. Odds ratios (OR) and 95% confidence intervals (CI) were estimated by logistic regression controlling for age, gender, number of children in household and H. pylori status of the father, mother and siblings. The prevalence of the infection was 69.7% (469 of 673) and it increased with age (P < 0.001). Positive mothers were a strong and independent risk factor for infection (OR 22.70;). Positive siblings were also positively associated with infection (OR 1.81; 95% CI 1.01-3.30).

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The babA2 and cagA genes were investigated in 208 Brazilian Helicobacter pylori strains. A strong association between babA2 and duodenal ulcer or gastric carcinoma was observed, even after adjusting for confounding factors, such as age, gender, and cagA status. cagA-positive strains were also independently associated with H. pylori-related diseases.Helicobacter pylori infection is one of the most common chronic bacterial infections worldwide. Although most infected persons remain asymptomatic, 15 to 20% of H. pylori-positive individuals will develop a peptic ulcer, gastric carcinoma, or mucosa-associated lymphoid tissue lymphoma (19). However, it remains unclear why only a minority of infected patients develop the severe associated diseases. This phenomenon may be due to differences in host genetics, environmental factors, and the virulence of bacterial strains.There is now evidence for the existence of different strains of H. pylori with different degrees of virulence (2,3,18). The cytotoxin-associated gene cagA was the first gene found to be differentially present in H. pylori isolates and is considered a marker for the presence of the cag pathogenicity island (4). In addition to other putative virulence properties encoded by the cag pathogenicity island, several genes of the island encode proteins, such as interleukin-8, that enhance the gastric inflammatory response to the infection.A cagA-positive status has been associated with severe clinical outcomes in some Western countries (3,14,18). Conversely, since the majority of H. pylori-infected individuals in Asian countries harbor cagA-positive strains, associations of cagA status and diseases are not observed in Asia (11,20). The recently described blood group antigen-binding adhesin BabA has been shown to mediate adherence of H. pylori to Lewis b (␣-1,3/4-difucosylated) receptors on gastric epithelium (8). Although three bab alleles have been identified (babA1, babA2, and babB), only the babA2 gene product is necessary for Lewis b binding activity (8,16). Studies in Western countries have demonstrated associations between babA2-positive status and duodenal ulcer as well as gastric carcinoma (7). However, in Asian countries, most of the circulating H. pylori strains are babA2 positive, whether or not they were isolated from asymptomatic or diseased patients (9,10,12,20). In addition to these differences between Western and Eastern countries, the prevalence of babA2-positive H. pylori strains also seems to vary among the Western populations, being much lower in patients from Portugal (13) than in those from Germany, the United States, or Colombia (7, 20). Since there are few studies on this subject, specifically evaluating patients with gastric carcinoma, the frequency of babA2 H. pylori strains may vary around the world and because the clinical relevance of babA2-positive strains has not been determined in Brazil, we investigated associations between babA2 and cagA genotypes and different H. pylori infection outcomes, adjusting for confounding factors.H Two ...

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The [13 C]urea breath test ( 13 C-UBT) and Helicobacter pylori stool antigen test (HpSA) for the diagnosis of H. pylori infection in children were validated. The sensitivity, specificity, and positive and negative predictive values were 93.8, 99.1, 97.8, and 98.0%, respectively, for the 13 C-UBT and 96.9, 100, 100, and 98.0%, respectively, for HpSA. Both tests are appropriate for diagnosing H. pylori infection in children. The [13 C]urea breath test ( 13 C-UBT) and a new developed immunoassay for the detection of Helicobacter pylori antigens in stool, the H. pylori stool antigen test (HpSA) (3), are noninvasive tests for H. pylori diagnosis.Although the 13 C-UBT has a good sensitivity for the diagnosis of the infection in all ages, low specificity for very young children has been found (6). With respect to the stool test, low sensitivity for this age group has been also reported (2, 10). Thus, we aimed to validate the 13 C-UBT and HpSA for the diagnosis of H. pylori infection in children.We studied prospectively 210 consecutive children aged 1 to 18 years who underwent esophagogastroduodenoscopy for investigation of gastric complaints. This project was approved by the Ethics Committee of our institution.At endoscopy, biopsy specimens were obtained from the antral and oxyntic gastric mucosa for culture, urease test, and histology. Children were considered to be H. pylori positive if at least two of the three tests were positive or if the culture alone was positive. They were considered negative if all tests were negative.The 13 C-UBT was performed on fasting children within 1 week after endoscopy. The children received 200 ml of orange juice containing 75 mg of [ 13 C]urea (or 100 ml containing 50 mg for those Ͻ30 kg). Breath samples at baseline and after 30 min were analyzed with a nondispersive infrared spectrometer (NDIRIS; Wagner Analysen Technik, Bremen, Germany). The results were considered positive when delta over baseline (DOB) was Ͼ4.0‰.Stool samples, collected on the occasion of the endoscopy, were maintained at Ϫ20°C for up 1 year before testing. HpSA (Premier Platinum HpSA; Meridian Diagnostic, Cincinnati, Ohio) was performed according to the manufacturer's recommendation, slightly modified: instead of a stick, a 10-l disposable loop was used to dilute stool samples, as proposed by Oderda et al. (9), and the plates were washed exhaustively to remove unbound material.Among the 210 children enrolled, 167 underwent the 13 C-UBT but 6 children were excluded (4 had only one positive test and 2 had equivocal results in the 13 C-UBT). The remaining 161 children (76 boys; mean age, 8.6 Ϯ 3.8 years; range, 1 to 18 years) were included in the final analysis (48 were H. pylori positive and 15 had peptic ulcer). The 13 C-UBT was positive for 45 of 48 infected children and for one of the 113 noninfected ones (Table 1). The three children with false-negative 13 C-UBT results were a 5-year-old boy (DOB ϭ 0.3), a 9-yearold girl (DOB ϭ 0.5), and a 14-year-old girl (DOB ϭ 0.2). The cultures for all of them were positiv...