<i>Helicobacter pylori</i>-associated hypochlorhydria in children, and development of iron deficiency

Harris, Paul; Serrano, Carolina; Villagrán, Andrea; Walker, Marjorie M.; Thomson, Melanie J.; Duarte, Ignacio; Windle, Henry J.; Crabtree, Jean E.

doi:10.1136/jclinpath-2012-201243

Cited by 43 publications

(53 citation statements)

References 42 publications

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“…This observation contrasts with that of adults, in whom H. pylori infections usually result in significant inflammation. Furthermore, in children who are positive for H. pylori , the levels of regulatory T cells (T regs ) and IL-10 secreting cells in the gastric mucosa are higher than in H. pylori infected adults (46, 47). Therefore, these observations suggest that in children the regulatory mechanisms at the gastric level are more active than in adults and this could contribute to the limited reactivity identified in CD4 + and CD8 + T RM cells.…”

Section: Discussionmentioning

confidence: 99%

Characterization and Functional Properties of Gastric Tissue-Resident Memory T Cells from Children, Adults, and the Elderly

et al. 2014

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T cells are the main orchestrators of protective immunity in the stomach; however, limited information on the presence and function of the gastric T subsets is available mainly due to the difficulty in recovering high numbers of viable cells from human gastric biopsies. To overcome this shortcoming we optimized a cell isolation method that yielded high numbers of viable lamina propria mononuclear cells (LPMC) from gastric biopsies. Classic memory T subsets were identified in gastric LPMC and compared to peripheral blood mononuclear cells (PBMC) obtained from children, adults, and the elderly using an optimized 14 color flow cytometry panel. A dominant effector memory T (TEM) phenotype was observed in gastric LPMC CD4+ and CD8+ T cells in all age groups. We then evaluated whether these cells represented a population of gastric tissue-resident memory T (TRM) cells by assessing expression of CD103 and CD69. The vast majority of gastric LPMC CD8+ T cells either co-expressed CD103/CD69 (>70%) or expressed CD103 alone (~20%). Gastric LPMC CD4+ T cells also either co-expressed CD103/CD69 (>35%) or expressed at least one of these markers. Thus, gastric LPMC CD8+ and CD4+ T cells had the characteristics of TRM cells. Gastric CD8+ and CD4+ TRM cells produced multiple cytokines (IFN-γ, IL-2, TNF-α, IL-17A, MIP-1β) and up-regulated CD107a upon stimulation. However, marked differences were observed in their cytokine and multi-cytokine profiles when compared to their PBMC TEM counterparts. Furthermore, gastric CD8+ TRM and CD4+ TRM cells demonstrated differences in the frequency, susceptibility to activation, and cytokine/multi-cytokine production profiles among the age groups. Most notably, children’s gastric TRM cells responded differently to stimuli than gastric TRM cells from adults or the elderly. In conclusion, we demonstrate the presence of gastric TRM, which exhibit diverse functional characteristics in children, adults, and the elderly.

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Section: Discussionmentioning

confidence: 99%

Characterization and Functional Properties of Gastric Tissue-Resident Memory T Cells from Children, Adults, and the Elderly

et al. 2014

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“…[41][42][43][44][45][46] Infected children are less susceptible to wheezing, allergic rhinitis and skin allergies. 41 Several meta-analyses have confirmed the relationship between unexplained iron deficiency anemia and infection with H. pylori, both in children and adults.…”

Section: Extra-intestinal Manifestationsmentioning

confidence: 99%

“…[42][43][44] Harris et al, in a prospective study, have demonstrated the correlation between H. pylori infection associated hypochlorhydia and the development of iron deficiency in 123 children. 45 Lu et al, evaluated the role of H. pylori in the pathogenesis of acute idiopathic thrombocytopenic purpura (ITP) and have shown that the prevalence of pediatric infections with H. pylori and controls ITP group were similar and amounted to 41.30% and 35.71%, respectively. 47 No difference was found between the initial platelet counts and megakaryocytes.…”

Section: Extra-intestinal Manifestationsmentioning

confidence: 99%

Clinical differences of Helicobacter pylori infection in children

Iwańczak¹,

Buchner²,

Iwańczak³

2017

Adv Clin Exp Med

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Helicobacter pylori infection is widely spread all over the world. The prevalence of H. pylori infection in the world varies and depends on numerous factors such as age, ethnicity, geographical and socioeconomic status. Humans have been in a symbiotic relationship with this bacterium for thousands of years. However 10-20% of people infected with H. pylori are likely to develop gastroduodenal diseases such as peptic ulcer disease, iron deficiency anemia, gastric mucosal atrophy, metaplasia, dysplasia, MALT lymphoma, or gastric adenocarcinoma. Most of these diseases develop as the infection progresses and they are likely to occur later in life among the elderly. In the following years, the use of modern molecular techniques has led to the discovery of new Helicobacter strains and their genotypic differentiation. Newly discovered Helicobacter microorganisms can colonize human gastrointestinal tract and bile ducts. This article summarizes the distinct features of H. pylori infection in children including its prevalence, clinical manifestation, indications for treatment and recommended schemes of eradication.

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“…17 Worldwide, H. pylori infection is the leading cause of inflammation, ulceration and neoplasia of the stomach, but children have significantly less H. pylori -associated inflammatory disease than adults. 18 Having shown that H. pylori burden, virulence factor prevalence and genotype distribution are similar in infected children and adults, 19,20 we reasoned that H. pylori infection in children might impact the microbial composition of the stomach, 21 potentially enhancing gastric T reg responses capable of down-regulating T helper 1 (T H 1)- and T H 17-mediated H. pylori inflammatory disease in infected children. To address this issue, we characterized the gastric microbiota in H. pylori -infected and non-infected children and adults in a region of Latin America where H. pylori is endemic and H. pylori -associated gastric cancer is the second leading cause of cancer-related mortality.…”

Section: Introductionmentioning

confidence: 99%

Helicobacter pylori infection is associated with an altered gastric microbiota in children

et al. 2017

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The intestinal microbiome in early life influences development of the mucosal immune system and predisposition to certain diseases. Because less is known about the microbiome in the stomach and its relationship to disease, we characterized the microbiota in the stomachs of 86 children and adults and the impact of H. pylori infection on the bacterial communities. The overall composition of the gastric microbiota in children and adults without H. pylori infection was similar, with minor differences in only low abundance taxa. However, the gastric microbiota in H. pylori-infected children, but not infected adults, differed significantly in the proportions of multiple high abundance taxa compared with their non-infected peers. The stomachs of H. pylori-infected children also harbored more diverse microbiota, smaller abundance of Firmicutes, and larger abundances of non-Helicobacter Proteobacteria and several lower taxonomic groups than stomachs of H. pylori-infected adults. Children with restructured gastric microbiota had higher levels of FOXP3, IL10 and TGFβ expression, consistent with increased T regulatory cell responses, compared with non-infected children and H. pylori-infected adults. The gastric commensal bacteria in children is altered during H. pylori infection in parallel with more tolerogenic gastric mucosae, potentially contributing to the reduced gastric disease characteristic of H. pylori-infected children.

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Helicobacter pylori-associated hypochlorhydria in children, and development of iron deficiency

Cited by 43 publications

References 42 publications

Characterization and Functional Properties of Gastric Tissue-Resident Memory T Cells from Children, Adults, and the Elderly

Characterization and Functional Properties of Gastric Tissue-Resident Memory T Cells from Children, Adults, and the Elderly

Clinical differences of Helicobacter pylori infection in children

Helicobacter pylori infection is associated with an altered gastric microbiota in children

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