Andrea Villagrán

Iron Status and Helicobacter pylori Infection in Symptomatic Children: An International Multi-Centered Study

Objective Iron 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. Methods In 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. Results The 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. Conclusions This 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.

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

Aims Acute Helicobacter pylori infection is associated with transient hypochlorhydria. In H pylori-associated atrophy, hypochlorhydria has a role in iron deficiency (ID) through changes in the physiology of iron-complex absorption. The aims were to evaluate the association between H pylori-associated hypochlorhydria and ID in children. Methods Symptomatic children (n=123) were prospectively enrolled. Blood, gastric juice and gastric biopsies were taken, respectively, for haematological analyses, pH assessment and H pylori determination, and duodenal biopsies for exclusion of coeliac disease. Stool samples were collected for parasitology/microbiology. Thirteen children were excluded following parasitology and duodenal histopathology, and five due to impaired blood analysis. Results Ten children were hypochlorhydric (pH>4) and 33 were H pylori positive. In H pylori-positive children with pH>4 (n=6) serum iron and transferrin saturation levels % were significantly lower (p<0.01) than H pylori-positive children with pH≤4. No differences in ferritin, or total iron binding capacity, were observed. In H pylori-negative children with pH>4, iron and transferrin saturation were not significantly different from children with pH≤4. Conclusions Low serum iron and transferrin in childhood H pylori infection is associated with hypochlorhydria. In uninfected children, hypochlorhydria was not associated with altered serum iron parameters, indicating a combination of H pylori infection and/or inflammation, and hypochlorhydria has a role in the aetiology of ID. Although H pylori-associated hypochlorhydria is transient during acute gastritis, this alters iron homeostasis with clinical impact in developing countries with a high H pylori prevalence.

Peptic ulcer disease in Helicobacter pylori-infected children: clinical findings and mucosal immune response.

Objectives: Peptic ulcer disease (PUD) is highly prevalent among adults but less common in children. Helicobacter pylori infection, the main cause of PUD, is, however, acquired extremely early in life. The aim of the study was to analyze clinical characteristics of children with PUD in a country with a high prevalence of the disease and to evaluate which host factors could determine this clinical outcome. Methods: Children referred for upper gastrointestinal (GI) endoscopy with suspicion of peptic diseases were included prospectively during an 8-year period. Antral biopsies were performed to determine H pylori presence and mucosal cytokines profile. Results: A total of 307 children between 3 and 18 years old were enrolled. Of the total, 237 children (46% boys) with complete data were included. H pylori infection was confirmed in 133 (56.1%) participants. Duodenal ulcer (DU) was diagnosed in 32 patients (13.5%); among them 29 were infected with H pylori (90.6%). Infected children had a nodular appearance of the gastric mucosa more often than noninfected children. Noninfected children had fewer lymphoid follicles and less inflammatory infiltrate than infected children. Only mucosal polymorphonuclear cell infiltration was more intense in DU-infected children as compared with non–DU-infected children. DU-infected children had higher levels of mucosal interferon-&ggr; than noninfected and non–DU-infected patients. Non–DU-infected children had also higher levels of mucosal interleukin-10 than noninfected patients (P < 0.05). Conclusions: PUD in children, especially DU, is strongly associated with H pylori infection in developing countries. There is no distinctive clinical presentation of children with PUD. T-helper cytokine balance may influence clinical outcomes in children.

Differences in lung glutathione metabolism may account for rodent susceptibility in elastase-induced emphysema development

Syrian Golden hamsters develop more severe emphysema than Sprague-Dawley rats after intratracheal instillation of the same dose of elastase/body weight. Although species variations in antielastase defenses may largely explain these results, other variables, such as differences in lung antioxidants, cannot be overlooked since oxidative stress modulates antiprotease activity. We propose that elastase instillation might affect lung glutathione (GSH) metabolism differently in these species. Our aim was to study in hamsters and rats, lung glutathione metabolism at different times, from the stage of diffuse alveolar damage to advanced emphysema. We measured total and oxidized glutathione content as well as activity and expression of enzymes related to GSH synthesis and redox cycling: gamma-glutamylcysteine synthetase, glutathione peroxidase, and glutathione reductase. Whereas rats showed no significant changes in these measurements, hamsters showed significant derangement in GSH metabolism early after elastase instillation: 25% fall in total GSH (P < 0.05) with no increase in oxidized glutathione associated with reduced enzyme activities 24 h after elastase [60% for gamma-glutamylcysteine synthetase (P < 0.01), 30% for glutathione peroxidase (P < 0.01), and 75% for glutathione reductase (P < 0.001)]. GSH homeostasis was restored at the end of the first week, involving transient increased expression of these enzymes. We conclude that elastase induces significant alterations in GSH metabolism of hamster lungs and no overall change in rat lungs. Although differences in disease severity may account for our findings, the hamster becomes vulnerable to functional inhibition of alpha(1)-antitrypsin by oxidants and thus, even more susceptible to injury than it would be, considering only its low alpha(1)-antitrypsin level.

Prevalencia de la infección por Helicobacter pylori en niños: estimando la edad de adquisición

Background: A 73% prevalence of Helicobacter pylori infection was estimated in adults in the 2003 Chilean National Health Survey. However, this infection is usually acquired during childhood. Aim: To determine the frequency of H. pylori infection in healthy Chilean children from a school in Santiago. Material and methods: A cross sectional study in a private/subsidized school in Santiago. Children aged less than 18 years were invited to participate. The parents of those who accepted answered a demographic survey and a stool sample was obtained from participants to detect H. pylori antigen using a monoclonal antibody ELISA kit. Results: We studied 144 students aged 10.6 ± 3.1 years (54% females). Twenty six participants (18.1%, 95% CI: 12.4-24.9%) had a positive test. Children from higher socioeconomic levels had a non-significant lower frequency of infection. No differences in the frequency of infection were observed by age, gender, household type or number of people living in it or history of breastfeeding. Conclusions: In this sample of children, an 18.1% frequency of H. pylori infection was observed.

Iron Deficiency and IL1β Polymorphisms in Helicobacter pylori-infected Children

Helicobacter pylori infection has been associated with an imbalance of iron homeostasis. IL‐1β has been related with iron absorption disturbances through a variety of mechanisms. The aim of this study was to evaluate the presence of polymorphic variants for IL‐1β cluster and gastric IL1β mRNA expression in H. pylori‐infected children and their relationship with hypochlorhydria and iron deficiency (ID).

La infección materna por Helicobacter pylori no aumenta el riesgo de contraer la bacteria en el primer trimestre de vida de sus lactantes

INTRODUCTION H. pylori infection is acquired early in childhood. However, there is little information available regarding the role of breastfeeding and neonatal acquisition of the infection. OBJECTIVE To evaluate factors affecting the acquisition of H. pylori in newborns and infants from infected mothers. PATIENTS AND METHOD Consecutive mothers and their newborns were recruited into the study from the maternity unit, immediately after delivery. After signing informed consent, one stool sample from the mother was obtained before hospital discharge. Three stool samples of the newborns were then collected at home at 15, 60, and 90 days of life, for the detection of H. pylori antigen (Monoclonal HpSAg, sensitivity 94% and specificity 97%). The socio-epidemiological and biomedical variables were also analysed using a questionnaire. RESULTS A total of 32 mother-child pairs (64 subjects) were enrolled. The mean maternal age was 30.1±5.1 years, with 53% vaginal delivery, and 85% exclusively breastfed. There were 13 (40%) infected mothers. No H. pylori infection was detected in newborns and infants up to 3 months of follow-up. No significant differences were found in socioeconomic level between infected versus non-infected mothers (both groups mostly in the very high socioeconomic category: 28% and 32%, respectively, P=.15) and in the number of family members between infected versus non-infected mothers (3.8±0.8 vs 4.2±1.8 persons, P=.18). CONCLUSION Despite having a significant percentage of H. pylori-infected mothers, no newborn was infected at the third month of life. The protective role of breastfeeding cannot be ruled out.

PP-7 CHILDHOOD RECURRENT ABDOMINAL PAIN IS ASSOCIATED WITH DUODENAL EOSINOPHILIA REGARDLESS OF H. PYLORI INFECTION.

Objectives: This study aimed to investigate histologic features of children with RAP undergoing upper gastrointestinal endoscopy, after exclusion of common organic disease. Methods: Children referred for endoscopy were prospectively enrolled at a single tertiary center between 2008 and 2010, after obtaining informed consent. Cases were defined as children with clinical diagnosis of RAP, as opposed to controls with suspicion of organic disease. Gastric and duodenal biopsies were analysed by pathologists blinded to indication. Demographic and clinical variables, H. pylori infection, biochemical, endoscopic and pathologic results were compared between cases and controls. Results: A total of 101 children were included after exclusion of villous enteropathy (n = 6) and parasitic, rotaviral or salmonella enteritis (n = 14), resulting in 72 cases and 29 controls. There were no significant differences in demographics, clinical symptoms, H. pylori infection and endoscopic findings between cases and controls. Duodenal eosinophil counts per 5 HPF were significantly increased in cases vs. controls (median (IQR) 86 (62–114) vs. 49 (31–88); p < 0.001) and did not differ regarding age, gender and H. pylori. Intraepithelial lymphocytes per 100 enterocytes were similar in cases vs. controls (19 (15–25) vs. 18 (14–23); p = 0.89) with ≥ 25 in 25% of cases. Duodenal eosinophilia was equally observed in H. pylori negative cases (n = 50) vs. controls (n = 19) (87 (61–119) vs. 53 (36–95); p = 0.01), as well as positive cases (n = 21) vs. controls (n = 10) (85 (55–105) vs. 42 (18–65); p = 0.03). Logistic regression yielded an adjusted odds ratio of 1.23 (95% CI 1.08–1.40) for duodenal eosinophilia in RAP. Conclusions: Children with a clinical diagnosis of RAP have marked duodenal eosinophilia, independent of H. pylori infection, suggesting the role of unknown infectious or allergic triggers in the pathogenesis of functional gastrointestinal disorders in childhood. Further research is needed on the diagnostic and therapeutic benefits of targeting duodenal eosinophilia.

Mo1786 Different Strains of H. pylori Induce Tolerogenic Dendritic Cells in Children

murine homolog of human enteropathogenic E. coli, mice develop a TH1-mediated colitis with the resulting pathology attributed to inflammatory monocytes recruited to the colon by the chemokine CCL2. Previous evidence demonstrates that C. rodentium-induced CCL2 expression occurs through an NF-κB mediated mechanism within colonic stromal cells, however due to the intimate contact that is formed between the intestinal epithelial cell (IEC) and C. rodentium, it is possible the IEC is also a significant source of CCL2. Thus, this study was designed to test the hypothesis that NF-κB-derived gene expression from intestinal epithelial cells is necessary for the exacerbation of colitis via the recruitment of inflammatory monocytes. A corollary hypothesis was that inflammatorymonocytes contribute to infectious colitis via NF-κB activation. To test these hypotheses, two different strains of mice in which classical NF-κB activation is defective via the deletion of IKKβ in either intestinal epithelial cells (IKKβΔIEC) or myeloid-derived cells (IKKβΔMye) were orally challenged with C. rodentium. There was a reduction in C. rodentium-induced colon mass, colonic histopathology, colonic inflammatory mediator gene expression, and neutrophil accumulation in IKKβΔIEC mice as compared to wild type controls at the peak of infection. We also observed reductions in C. rodentium-induced colonic pathology, which was accompanied by increased macrophage accumulation in IKKβΔMye mice at the height of the infection. Interestingly, both IKKβΔIEC and IKKβΔMye mice had significantly higher levels of tumor necrosis factor (TNF)-α, as well as inducible nitric oxide synthase (i.e., iNOS) gene expression within the colon prior to C. rodentium challenge. Although exact mechanisms that render deficient mice more resistant to C. rodentium-induced colonic pathology remain to be elucidated, our data suggest that the deletion of canonical NF-κB signaling within epithelial cells of the colon is sufficient to create an environment which is unfavorable for the colonization by non-invading pathogens, including C. rodentium.

Sa2003 Increased Duodenal Intra Epithelial Lymphocytes (IELs) are Associated With Recurrent Abdominal Pain and Parasite Infection but Not Helicobacter pylori in a Paediatric Chilean Cohort

Introduction Functional Recurrent Abdominal Pain (RAP) is a paediatric functional gastrointestinal disorder with poorly investigated pathophysiology. Proposed aetiology varies and the diagnosis is characterised by Rome III criteria. Some studies consider Helicobacter pylori to be a cause of RAP, while others disagree. The aim of this study was to investigate upper gastrointestinal pathology in a cohort of 123 children in Chile with respect to RAP, H pylori infection and other concurrent infection. Methods This blinded retrospective and IRB-approved study analysed biopsies taken from the gastric antrum and body and the duodenum in 123 Chilean children referred to endoscopy (with informed parental consent). Histopathology was evaluated against a clinical database which included symptoms, symptom duration and endoscopy findings. Rome III criteria were used to assign RAP to the relevant cases. All patients had stool microbiology and parasitology. H pylori infection was assessed by serology and histology. In the duodenum, routine histopathology and also eosinophil counts (in 5HPF ×40 magnification), were performed by microscopy. IELs/100 enterocytes were counted. Independently those patients with IELs >25 had serology performed for coeliac disease. Results Overall 105 patients were diagnosed with RAP and 12 patients were able to act as controls, having no symptoms of RAP or concurrent infection. The Rome III diagnosis of RAP was significantly associated with higher IEL counts (>20 in 74 patients) compared to controls (p=0.04). Furthermore, a higher IEL count was also positively associated with parasitic infection (nine with parasites) (p=0.02). Of 16 patients with lymphocytic duodenosis, (>25 IELs per 100 enterocytes) only three were infected by H pylori . One had coeliac disease with positive serology. Antral nodularity was observed in association with lymphoid follicles (p≤0.01) and H pylori infection (p H pylori but infection was not significantly associated with RAP (p=0.55) or parasite infection, as concurrent infection was present in only 2 patients (p=0.24). Conclusion From this study, low grade inflammation, manifest by increased IELs, may be associated with RAP and also parasitic infection. H pylori is not associated with parasite infection. However, as eosinophilia was not significantly associated with the condition further investigation is required to elucidate the potential involvement of innate immunity, including mast cells. Furthermore, there is no association between H pylori infection and RAP. Funded by EU CONTENT Project (INCO-CT-2006-032136), CONICYT/BM (RUE #29) and Fondecyt #1100654 (Chile). Competing interests None declared.