Virulence factor genotyping of Helicobacter pylori isolated from Costa Rican dyspeptic patients.

BACKGROUND AND AIMS: Costa Rica is one of the countries with the highest incidence and mortality rates for gastric cancer. Helicobacter pylori infection rates are high in the whole country. We have previously shown that H. pylori CagA+ is significantly associated with atrophic gastritis (AG) of the antrum in a dyspeptic population. The aim of this work is to determine if other H. pylori virulence factors (vacA, dupA, oipA, iceA and babA2) are associated with atrophic gastritis (AG) or duodenal ulcer (DU). METHODS: The presence of virulence genes in Costa Rican H. pylori isolates was analyzed by PCR in 151 cultured strains from patients with dyspeptic symptoms. Endoscopic and histopathological diagnoses were available. Odds-ratio and 95% confidence intervals for AG patients vs. non-atrophic gastritis (NAG) or DU patients vs. no duodenal ulcer (NDU) patients were calculated. RESULTS: Amongst the studied isolates, 82% had the cagA+, 76.2% had the vacA s1m1, 97.0% had the oipA+, 21.0% had the icea1, 79.0% had the iceA2, 44.0% had the babA2+ and 76.0% the dupA+ genotypes. Infection with H pylori cagA+, dupA+, oipA+, iceA, babA2+, and vacA s1m1 genotypes was not associated with AG risk. The frequency of the dupA gene was 78.7 and 60.9% in isolates from patients with NDU and DU, respectively, and its presence was significantly associated with decreased risk of duodenal ulcer [odds-ratio: 0.33, p = 0.024, confidence interval 95% (0.11-0.85)]. CONCLUSION: H. pylori dupA genotype is inversely associated with DU risk in this population.

Geraniol-a flavoring agent with multifunctional effects in protecting the gastric and duodenal mucosa.

Geraniol is an acyclic monoterpene alcohol commonly used as a flavoring agent. The present study was undertaken to investigate antiulcerogenic effects of geraniol and to determine the possible mechanisms involved in this action. In the model of the ethanol-induced ulcer, treatment of rats with geraniol by oral route significantly inhibited gastric lesions by 70 % (7.50 mg/kg) to 99 % (200 mg/kg). Analysis of the gastric tissue of rats treated with geraniol (7.50 mg/kg) revealed that total glutathione content levels (GSH) increased and levels of myeloperoxidase (MPO) decreased in the gastric mucosa. Oral treatment with geraniol significantly decreased the number of ulcerative lesions induced by ischemia/reperfusion injury by 71 % and the duodenal ulcers induced by cysteamine by 68 %. The action of geraniol was mediated by the activation of defensive mucosa-protective factors such as the nitric oxide (NO) pathway, endogenous prostaglandins, increased mucus production, increased sulfhydryl compounds, antioxidant properties and the stimulation of calcitonin gene-related peptide (CGRP) release through the activation of transient receptor potential vanilloid (TRPV). The multifaceted gastroprotective mechanisms of geraniol represent a promising option for the treatment of gastric and duodenal mucosa injury.

Cystic fibrosis, gastroduodenal inflammation, duodenal ulcer, and H. pylori infection: the "cystic fibrosis paradox" revisited.

BACKGROUND: In cystic fibrosis (CF) patients a duodenal impaired bicarbonate secretion and unbuffered gastric acid are always described and the development of duodenal ulceration is uncommon (CF paradox). Helicobacter pylori (HP) infection is the main cause for duodenal ulceration and its prevalence in CF patients is controversial. AIM: The objective of this study is to evaluate HP prevalence, gastric histology, and duodenal ulceration in adult FC patients. METHODS: 32 adult CF patients were submitted to (13)C-urea breath test and serum immunoblotting test for HP diagnosis. Among them, 20 patients were submitted to endoscopy. RESULTS: 19/32 (68%) patients showed positive serology. Endoscopy showed erosive duodenitis (15%), and duodenal ulcer scar in 10%. On duodenal histology, 94.5%, showed active inflammation and 66.7% gastric metaplasia. CONCLUSION: HP infection prevalence in adult CF patients was similar to that of general Brazilian population. CF patients have all the duodenal spectrum of alterations, including duodenal ulcer. CF paradox may not exist.

Gastroprotective effects of extracts and guttiferone A isolated from Garcinia achachairu Rusby (Clusiaceae) against experimentally induced gastric lesions in mice.

This study was undertaken to evaluate the gastroprotective properties of seed, leaf, and branch methanolic extracts and guttiferone A obtained from Garcinia achachairu (Clusiaceae). Mice were used in all the models, and treatments were administered orally only in pylorus-ligated model of the extracts, and drugs were administered intraduodenally. Treatment with different extracts (500 mg/kg) significantly reduced the ulcerative lesions in the ethanol/HCl-induced model; however, the seed extract was most active. When tested in different doses (50, 250, or 500 mg/kg), the seed extract of G. achaicharu showed a dose-dependent effect with a percentage of inhibition of gastric lesions of 41, 49, and 85 %, respectively. The seed extract also significantly reduced the ulcerative lesions in the indomethacin/bethanechol-induced ulcer. In this model, the percentage of inhibition of ulcer was 24, 58, and 90 %, respectively. Regarding the model of gastric secretion, a reduction of gastric juice volume and total acidity was observed, as well as an increase in gastric pH. Considering that the seed extract was the most active, it was subjected to silica gel column chromatography, leading to the isolation of guttiferone A. The isolated compound and omeprazole were evaluated in the HCl/ethanol-induced ulcer model. In this assay, both compounds at a dose of 30 mg/kg reduced the ulcerative lesions by about 75 %. These results demonstrate, for the first time, that extracts obtained from G. achachairu and guttiferone A produce gastroprotective effects, corroborating ethnomedicinal use of this plant.

[Characteristics of gastroduodenal ulcers in patients with negative biopsies for Helicobacter pylori]. / Caracteristicas de las ulceras gastroduodenales en pacientes con biopsia negativa para helicobacter pylori.

OBJECTIVES: To evaluate the clinical, epidemiological and endoscopic characteristics of the Helicobacter pylori (Hp) negative peptic ulcer disease. METHODS: In this cross sectional study we included 651 patients diagnosed of peptic ulcer disease between January 2000 and December 2005. The diagnosis of Hp infection was established by histology. Clinical and epidemiological characteristics of patients with and without Hp infection were compared. RESULTS: Males prevailed (69%). Hp negative ulcers were older (57.73 +/- 19.44 years old vs 50.26 +/- 18, 64 years old, P < 0.001). Clinical characteristics did not differ among both groups. Duodenal ulcer prevailed in Hp positive patients (56.5%) and gastric ulcer in Hp negative patients (53.5%). Multiple ulcers and intestinal metaplasia were more frequently found in Hp negative cases [9.3% vs 4.5% (P = 0.015) and 34.5% vs 22.1% (P = 0.001), respectively]. CONCLUSION. Hp negative peptic ulcer disease is found in older patients, with a higher frequency of gastric ulcers, multiple lesions and intestinal metaplasia.

Polymorphisms in TNF and HSP-70 show a significant association with gastric cancer and duodenal ulcer.

Tumour Necrosis Factor (TNF) and Heat Shock Protein 70 (HSP70) are important molecules in inflammatory, infectious and tumoral processes. The genes codifying these molecules are polymorphic and certain alleles have been associated with susceptibility to disease. Gastric cancer is associated with an Helicobacter pylori-induced chronic inflammatory response. The aim of this work was to analyze whether polymorphisms in inflammation-related genes are associated with the development of gastric cancer. We studied 447 Mexican adult patients including 228 with non-atrophic gastritis, 98 with intestinal metaplasia, 63 with gastric cancer and 58 with duodenal ulcer, and 132 asymptomatic individuals as well. DNA from peripheral white blood cells was typed for the Single Nucleotide Polymorphisms (SNPs) -308 of TNF-alpha, +252 of TNF-beta, +190 of HSP70-1, +1267 of HSP70-2 and +2437 of HSP70-HOM. Compared with the asymptomatic group, we found a significant association of TNF-beta*A and HSP70-1*C alleles with gastric cancer (OR 5.69 and 3.76, respectively) and HSP70-1*C with duodenal ulcer (OR 3.08). Genotype TNF-beta G/G showed a significant gene-dose effect with gastric cancer (OR 0.09); whereas HSP70-1 C/G showed significant association with both, gastric cancer (OR 13.31) and duodenal ulcer (OR 16.19). Polymorphisms in TNF and HSP70 showed a significant severity-dose-response as risk markers from preneoplastic lesions to gastric cancer in Mexican population, probably because of their association with an intense and sustained inflammatory response.

Helicobacter pylori recurrence in patients with duodenal ulcer: Clinical, endoscopic, histologic, and genotypic aspects. A 10-year Brazilian series.

BACKGROUND: Recurrence infection following successful eradication of Helicobacter pylori is usually low, except for countries with high prevalence of H. pylori. The aim of this study was to verify H. pylori recurrence rate in patients with duodenal ulcer after eradication and the possible relationship with environmental factors, histologic pattern of the mucosa and bacterial genotype. MATERIALS AND METHODS: One-hundred and ninety-four patients with an active duodenal ulcer and who were successfully treated for H. pylori infection from 1990 to 1999 were studied. A questionnaire was answered about their living conditions, and a 14C-urea breath test was performed. Patients with a positive breath test underwent an upper endoscopy to investigate for possible ulcer recurrence; gastric biopsy samples were than collected for rapid urease test and for histologic assessment. H. pylori vacA and cagA genotype was determined by polymerase chain reaction in those samples with positive urease test. RESULTS: H. pylori infection was detected in 11 patients (recurrence rate of 5.7%) that were not associated with the type of bacterial virulence. In 10 patients the ulcer was healed and all of them were clinically asymptomatic. In eight, histology showed an intensification of gastritis. All 11 patients had adequate housing and sanitary conditions and no other risk for H. pylori recurrence was identified. CONCLUSIONS: The recurrence rate of H. pylori in Brazil was higher than that reported in developed countries, but lower than usually reported in developing ones. Ulcer relapse rarely occurs even in long-term follow up.

Topographic expression of MUC5AC and MUC6 in the gastric mucosa infected by Helicobacter pylori and in associated diseases.

We investigated the topographic expression of MUC5AC and MUC6 in relationship with gastric diseases. The immunoexpression of MUC5AC and MUC6 was evaluated in 75 adults presenting Helicobacter pylori gastritis (n = 22; 11 cagA positive), duodenal ulcer (DU, n = 11), gastric ulcer (GU, n = 9), gastric carcinoma (GC, n = 20), and normal mucosa (H. pylori negative, n = 13). Five gastric areas (antral and corporeal lesser and greater curvatures and incisura) were studied. H. pylori was detected by carbolfuchsin, urease, and culture; cagA was determined by PCR. All patients with DU (eight with GU and 13 with GC) were H. pylori-positive. In H. pylori gastritis, MUC5AC expression was higher in the antrum than in the corpus; no difference was observed with respect to cagA status. MUC5AC expression was higher in the antrum of gastritis than in DU, and it was lower in the incisura among GU patients compared to DU. MUC6 expression was higher in the antrum of H. pylori gastritis compared to DU and to uninfected patients. No difference was observed in the topographic pattern of expression of MUC5AC and MUC6 among GC cases. The topographic over- and under-expression of mucins in H. pylori-associated gastritis and peptic disease suggest a role for these mucins in the pathogenesis of H. pylori infection and associated diseases.

[Clinical and histological features of duodenal ulcer in children and adolescents]. / Aspectos clínicos e histológicos da úlcera duodenal em crianças e adolescentes.

OBJECTIVE: To evaluate clinical and histological features of duodenal ulcer in children and adolescents. METHODS: Forty-three children with duodenal ulcer were prospectively and consecutively evaluated in a 6-year period (7.2 patients per year). Evaluation included clinical questionnaire focused on dyspeptic symptoms, physical examination, and digestive endoscopy with gastric biopsies for histological examination and Helicobacter pylori detection. RESULTS: Diagnostic age ranged from 4 years and 8 months to 17 years and 4 months (mean age: 12 years and 4 months). Abdominal pain was the main symptom (39/43, 90.7%), which was epigastric in 31/39, periumbilical in 7/39, and nocturnal in 27/39. Other symptoms were loss of appetite (32/43, 74.4%), vomiting (30/43, 69.8%), postprandial fullness (23/43, 53.5%), weight loss (22/43, 51.2%), and abdominal tenderness (19/43, 44.2%). Upper gastrointestinal bleeding occurred in 19/43 (44.2%), whereas anemia occurred in (21/43, 48.8%). Helicobacter pylori infection was detected in 41/43 (95.3%). All infected patients presented acute chronic gastritis in antrum, with lymphomononuclear infiltrate predominance in 92% of them. Eradication of the bacterium occurred in 68.3%. Ulcer healing occurred in all eradicated patients and in 89% of non-eradicated patients. CONCLUSION: Duodenal ulcer was associated with chronic gastritis due to Helicobacter pylori in the majority of patients. Many complications occurred, especially upper digestive bleeding.

Aspectos clínicos e histológicos da úlcera duodenal em crianças e adolescentes / Clinical and histological features of duodenal ulcer in children and adolescents

OBJETIVO: Avaliar as características clínicas e histológicas de crianças e adolescentes com úlcera duodenal. MÉTODOS: Foram avaliadas prospectiva e consecutivamente 43 pacientes com úlcera duodenal ao longo de 6 anos (7,2 pacientes por ano). A avaliação consistiu de questionário clínico de sintomas dispépticos, exame físico e endoscopia digestiva com biópsias gástricas para exame histológico e detecção do Helicobacter pylori. RESULTADOS: A idade no diagnóstico variou de 4 anos e 8 meses a 17 anos e 4 meses (mediana = 12 anos e 4 meses). O sintoma mais freqüente foi dor abdominal (39/43, 90,7 por cento): no epigástrio em 31/39, periumbilical em 7/39 e noturna em 27/39. Outros sintomas freqüentes foram: diminuição do apetite (32/43, 74,4 por cento), vômitos (30/43, 69,8 por cento), plenitude pós-prandial (23/43, 53,5 por cento), perda de peso (22/43, 51,2 por cento) e sensibilidade abdominal (19/43, 44,2 por cento). Hemorragia digestiva alta ocorreu em 19/43 pacientes (44,2 por cento), e anemia em 21/43 (48,8 por cento). H. pylori foi detectado em 41/43 (95,3 por cento), e todos esses pacientes apresentaram gastrite crônica ativa de antro, 92 por cento deles com predomínio do infiltrado linfomononuclear. A erradicação da bactéria ocorreu em 68,3 por cento dos pacientes infectados, mas houve cicatrização da lesão em 100 por cento dos pacientes erradicados e em 89 por cento dos não-erradicados. CONCLUSAO: Ulcera duodenal foi associada à gastrite crônica por H. pylori na grande maioria dos pacientes. Houve grande freqüência de complicações, especialmente hemorragia digestiva alta.

CagA antibodies as a marker of virulence in chilean patients with Helicobacter pylori infection.

BACKGROUND: The bacterial and host factors that influence the clinical outcomes of the Helicobacter pylori infection have not been fully identified. Cytotoxin-associated gene product (CagA), one of the virulence factors, has been associated with a more aggressive form of infection. The authors studied the relationship between CagA status and clinical outcome in Chilean children and adults with H. pylori infection. METHODS: One hundred eighty consecutive patients undergoing upper gastrointestinal endoscopic analysis were enrolled after informed consent was obtained. Rapid urease test and histologic analysis were used to detect H. pylori infection. IgA and IgG antibodies to H. pylori whole cell antigen preparation and IgG antibodies to CagA were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: H. pylori infection was detected in 42% of the patients by biopsy or urease test and in 38% and 20% of patients by IgG and IgA antibodies, respectively. The prevalence of H. pylori either by the invasive or the serologic tests was directly related to patient age. Among patients with H. pylori, there was no significant association between age and prevalence of CagA. Nearly 70% of the patients with H. pylori and peptic ulcer disease had CagA-positive strains. In contrast, only 49% of the patients with chronic gastritis alone had CagA-positive strains (P < 0.05). CONCLUSIONS: In Chile, patients infected with H. pylori have a proportion of CagA-positive strains similar to that reported in developed countries. CagA prevalence was not significantly different in adults and children infected with H. pylori, suggesting that variations in clinical outcome may be related to host immune or environmental factors.

Effects of tea from Turnera ulmifolia L. on mouse gastric mucosa support the Turneraceae as a new source of antiulcerogenic drugs.

Turnera ulmifolia is a plant belonging to the family Turneraceae, popularly known in Brazil as chanana. This species is distributed from Guyana to southern Brazil where it is considered a weed. The plant occurs in tropical rain forest, fields, and gardens. Chanana tea is used in Brazilian folk medicine for the treatment of diseases related mainly to gastric dysfunction including gastric and duodenal ulcers. In this study, the ability of a lyophilized infusion, as an aqueous fraction (AqF) of the aerial parts of T. ulmifolia, was investigated for its ability to prevent ulceration of the gastric and duodenal mucosa was examined in mice and rats, respectively. The AqF significantly reduced the formation of lesions associated with HCl/ethanol administration by 39% and 46%, respectively, at doses of 500 mg/kg and 1000 mg/kg, p.o. The AqF also significantly reduced the incidence of gastric lesions induced by a combination of indomethacin and bethanechol by 58% and 72% at doses of 500 mg/kg and 1000 mg/kg, respectively. In stress-induced gastric ulcer, the inhibition by the AqF was 48%, 57%, and 58% at doses of 250 mg/kg, 500 mg/kg, and 1000 mg/kg, respectively (p<0.05). A pyloric ligature experiment showed that the highest dose of the AqF significantly affected the gastric juice parameters by increasing the pH from 2.5 (control) to 5.3 and decreasing the acid output from 11.3 (control) to 3.7 mEq/ml/4 h. The AqF had no significant effect on duodenal ulcers induced by cysteamine. Preliminary phytochemical screening confirmed that flavonoids were the major constituents of the AqF of T. ulmifolia. These results indicate that this extract has a significant antiulcerogenic effect, as popularly believed.

[Gastroduodenal Crohn's disease - report of 4 cases and review of the literature]. / Doença de Crohn gastroduodenal - relato de quatro casos e revisão da literatura.

BACKGROUND: Crohn's disease can affect all the gastrointestinal tract, but gastroduodenal involvement is rarely seen (0.5 to 13%). OBJECTIVES: Report clinical, radiological and endoscopic findings and treatment of four patients with gastroduodenal Crohn's disease and review the literature. PATIENTS AND METHODS: Four patients (one male of 24 years old three females of 37, 66 and 74 years old) with epigastric pain, weight loss and low grade fever were referred to the University Hospitals of Federal University of Rio de Janeiro and Fluminese Federal University. Two had also mild intermittent diarrhea and arthritis/arthralgia and the third developed pyloric obstruction and received surgical treatment. Anemia was observed in only one (the young female). Barium x-ray studies showed aphthous ulcers in stomach and duodenum with distal ileum lesions and deformity in both. Upper gastrointestinal endoscopy revealed aphthous ulcers in stomach and geographic duodenal ulcers. Polypoid lesions and serpiginous ulcers within gastric antrum were observed in the young female. Colonoscopy was performed in two patients and disclosed an ulcerated ileitis in one and ulcerated pancolitis in other. Histopathology findings of biopsy specimens were inconclusive (granulomas were not found) and other causes of granulomatous disease were ruled out. Corticosteroids and proton pump inhibitors were started and two patients had their disease controlled. The other patient developed pyloric obstruction and had to be operated. CONCLUSIONS: Gastroduodenal Crohn's disease has distinct clinical, therapeutic and prognostic features. Advances in endoscopic methods and recognition of new histopathologic criteria for diagnosis have revealed an incidence higher than previously reported.

Geographic differences in the distribution of intestinal metaplasia in duodenal ulcer patients.

OBJECTIVE: A strong correlation exists between atrophic gastritis and the intestinal type of gastric carcinoma. Duodenal ulcer disease characteristically has an antral predominant gastritis and a lower risk for gastric cancer. The aim of this study was to investigate the extent and distribution of intestinal metaplasia in duodenal ulcer in countries differing in gastric cancer incidence. METHODS: Topographically mapped gastric biopsy specimens (median 11) were obtained from patients with duodenal ulcer in four countries (Korea, Colombia, USA, and South Africa). Sections were stained with a triple stain and evaluated for Helicobacter pylori (H. pylori), active inflammation, and intestinal metaplasia. RESULTS: One hundred and sixty-five patients with duodenal ulcer were examined (29 from Korea, 52 from Colombia, 62 from the USA, and 22 from South Africa). The percentage of biopsies with intestinal metaplasia was significantly greater in Korean patients (86%) compared with that in other countries (50%) (p = 0.0004). Intestinal metaplasia was most prevalent in the antrum lesser curve and greater curve, and the body lesser curve. Intestinal metaplasia was present in the gastric corpus of 38% of duodenal ulcer patients from Korea compared with an average of 10% elsewhere (p = 0.018). No differences were observed in the density or distribution of H. pylori infection or in the degree of active gastritis between countries. CONCLUSIONS: Although antral predominant gastritis is the prevalent pattern of gastritis in duodenal ulcer, intestinal metaplasia in the gastric corpus may be found with geographic differences. These findings suggest that duodenal ulcer and gastric cancer are not mutually exclusive diseases but are rather ends of the spectrum of H. pylori infection.

Doença de Crohn gastroduodenal-relato de quatro casos e revisao da literatura / Doença de Crohn gastroduodenal - relato de quatro casos e revisao da literatura

BACKGROUND: Crohn's disease can affect all the gastrointestinal tract, but gastroduodenal involvement is rarely seen (0.5 to 13 per cent). OBJECTIVES: Report clinical, radiological and endoscopic findings and treatment of four patients with gastroduodenal Crohn's disease and review the literature. PATIENTS AND METHODS: Four patients (one male of 24 years old three females of 37, 66 and 74 years old) with epigastric pain, weight loss and low grade fever were referred to the University Hospitals of Federal University of Rio de Janeiro and Fluminese Federal University. Two had also mild intermittent diarrhea and arthritis/arthralgia and the third developed pyloric obstruction and received surgical treatment. Anemia was observed in only one (the young female). Barium x-ray studies showed aphthous ulcers in stomach and duodenum with distal ileum lesions and deformity in both. Upper gastrointestinal endoscopy revealed aphthous ulcers in stomach and geographic duodenal ulcers. Polypoid lesions and serpiginous ulcers within gastric antrum were observed in the young female. Colonoscopy was performed in two patients and disclosed an ulcerated ileitis in one and ulcerated pancolitis in other. Histopathology findings of biopsy specimens were inconclusive (granulomas were not found) and other causes of granulomatous disease were ruled out. Corticosteroids and proton pump inhibitors were started and two patients had their disease controlled. The other patient developed pyloric obstruction and had to be operated. CONCLUSIONS: Gastroduodenal Crohn's disease has distinct clinical, therapeutic and prognostic features. Advances in endoscopic methods and recognition of new histopathologic criteria for diagnosis have revealed an incidence higher than previously reported.

[Helicobacter pylori. Its relationships and morphological controversies]. / Helicobacter pylori. Sus relaciones y controversias morfológicas.

After Helicobacter pylori was described in 1984, it has been related to numerous benign and malignant morphological disturbances. The distribution of the gastroduodenal disease, their histological expressions and their controversial topics regarding their relationship with HP are better known today. The aim of this paper is review some of these features.

Omeprazole, clarithromycin and furazolidone for the eradication of Helicobacter pylori in patients with duodenal ulcer.

AIM: To evaluate the efficacy of omeprazole plus clarithromycin and furazolidone in Helicobacter pylori eradication and duodenal ulcer healing in Brazilian patients. METHODS: Forty H. pylori-positive patients with duodenal ulcer were randomized to receive 20 mg omeprazole o.m. or b.d. for 1 month plus 500 mg clarithromycin (b.d. ) and 200 mg furazolidone (b.d.) for 1 week. RESULTS: Three months after the end of the treatment the eradication rates were 90% by intention-to-treat analysis, and 97% by per protocol analysis. Mild side-effects were observed in 25 patients, none of whom abandoned the protocol. No difference was observed between the 20 mg and 40 mg omeprazole daily doses. Cure or significant improvement of the symptoms and of the histological alterations were observed after H. pylori eradication. CONCLUSION: Our results demonstrate that clarithromycin and furazolidone in combination with omeprazole are a good alternative for H. pylori eradication in Brazilian patients with duodenal ulcer.

Evaluation of enzyme-linked immunosorbent assay for the diagnosis of Helicobacter pylori infection in children from different age groups with and without duodenal ulcer.

BACKGROUND: Although enzyme-linked immunosorbent assay (ELISA) is highly sensitive and specific for the diagnosis of Helicobacter pylori infection in adults, their performance in children is still controversial. METHODS: A second-generation ELISA was used to evaluate the IgG response to H. pylori in the serum of 130 consecutive children who underwent upper gastrointestinal endoscopy. The presence of H. pylori was determined in antral biopsy specimens by culture, urease test, and histologic analysis. RESULTS: Sixty-eight children (all of the 20 who had duodenal ulcer) were H. pylori positive by microbiologic test. Immunoglobulin G antibodies to H. pylori were detected in 79.4% of the infected children and in 8.1% of the noninfected ones. The sensitivity of the test was higher in patients with duodenal ulcer (100%) than in those without (70.8%). When used in children of different ages the test also presented differences in sensitivity: 44.4% in children 2 to 6 years old; 76.7% in children 7 to 11 years old, and 93.1% in children 12 to 16 years old (p = 0.006). The serum immunoglobulin G concentration was significantly higher (p = 0.0003) in children with duodenal ulcer than in those without and was higher in older children than in younger ones without duodenal ulcer (p = 0.05). CONCLUSIONS: The accuracy of the test in children with duodenal ulcer and in children more than 12 years old was good; however, in children up to 12 years of age without duodenal ulcer, the sensitivity of the test was too low to be used for screening purposes or to rule out the presence of infection.