iceA genotypes of Helicobacter pylori strains isolated from Brazilian children and adults.

Data concerning the geographic distribution of iceA alleles are scarce, and information on the association of the gene with the disease is rare and still controversial. Furthermore, no such study has been developed in Brazil, where duodenal ulcer and gastric adenocarcinoma are very common. We investigated, by PCR, the frequency of iceA alleles and cagA status in Helicobacter pylori strains isolated from 142 patients (62 children and 80 adults; 66 female; mean age, 30.0 years; age range, 3 to 78 years) with gastritis, duodenal ulcer, or gastric adenocarcinoma. iceA was identified in bacterium samples obtained from all patients. Eleven (7.7%) of them were infected with multiple strains. Among the patients with nonmixed infection, iceA2 allele was detected in 118 (90.1%). iceA2 allele was associated with ulcer (P = 0.02) and with carcinoma (P = 0.001). iceA2 amplicons of 229, 334, or 549 bp were detected, but none of them was associated with the patient's disorder. iceA2 strains were more frequent in patients older than 7 years (P = 0.001). The gene was also more frequent in strains obtained from males (P = 0.02). cagA was more common in strains obtained from carcinoma (P = 0.0008) and ulcer patients (P < 0.006). cagA-positive strains were more frequent in children older than 7 years (P < 0.003). No association between cagA status and sex was found (P = 0.28). In conclusion, we think iceA should not be used as a reliable marker for predicting the clinical outcome of H. pylori infection.

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.

Effect of Helicobacter pylori eradication on G-cell and D-cell density in children.

Helicobacter pylori infection is associated with abnormalities in serum gastrin concentration, antral gastrin and somatostatin content, and D-cell density in adults. We have studied the effects of H pylori infection in children. We studied 13 children positive for H pylori and 7 negative children. The median antral somatostatin content was significantly lower in the positive than in the negative group (0.69 [range 0.35-0.91] vs 1.31 [0.73-1.67] ng/mg, p = 0.007). Both antral and serum gastrin concentrations were significantly higher in the positive group (30.1 [15.3-83.6] vs 14.8 [13.8-28.8] ng/mg, p = 0.008; and 89.9 [59.4-313.2] vs 29.5 [13.9-71.1] pg/mL, p = 0.006). Treatment to eradicate H pylori was successful in 11 of the 13 positive patients. With eradication antral somatostatin increased to within the normal range (by a median of 0.41 [0.21-0.86] ng/mg to 1.10 [0.81-1.55] ng/mg, p = 0.016). Serum and antral gastrin decreased (by 37.1 [5.5-265.2] pg/mL to 52.8 [21.4-267.5] ng/mg, p = 0.001; and by 8.0 [2.0-47.2] ng/mg to 22.1 [10.9-37.5] ng/mg, p = 0.001). Eradication of H pylori also significantly increased antral D-cell density (8 [5-22] to 15 [9-22] cells per mm, p = 0.031) and decreased G-cell density (138 [89-161] to 88 [33-121] cells per mm, p = 0.016). The hypergastrinaemia in children positive for H pylori may be due to a deficiency of antral somatostatin, which inhibits gastrin synthesis and release.

Serodiagnosis of Helicobacter pylori infection in children by an indirect immunofluorescence test.

The objective of this study was to evaluate the accuracy of an indirect immunofluorescence (IIF) test for serodiagnosis of Helicobacter pylori infection in children and to determine how the test is affected by the presence of antibodies against Campylobacter jejuni. We studied 65 consecutive children (two with endoscopically confirmed duodenal ulcer) and a series of 18 children with duodenal ulcer. Thirty children were H. pylori negative, as determined by culture, by the preformed urease test, and by carbolfuchsin-stained smears. The microorganism was identified by microbiological methods in 35 of the 65 (53.85%) consecutive patients studied and in all children with duodenal ulcer. The titer of the IIF test was > or = 1:20 in the sera of all children with duodenal ulcer and in the sera of 30 of 33 H. pylori-positive children without duodenal ulcer. No H. pylori-negative children had titers > 1:10. A serum dilution of 1:20 discriminated between H. pylori-infected and noninfected children. Absorption with C. jejuni did not change the levels of IgG against H. pylori. When five patients who had been successfully treated with metronidazole, amoxycillin, and furazolidone for 7 days were retested, a slight decrease in anti-H. pylori IgG levels was noted from the third month on. The decrease was more significant 9 months after the eradication of the microorganism.

Coeliac disease in identical twins.

Coeliac disease occurred at the same age in MZ twins. The diagnosis was confirmed by histology of the small intestine, rapid response to a gluten-free diet, and relapse after reintroduction of gluten.