Iron deficiency and Helicobacter pylori infection in children

Helicobacter pylori-Associated Iron Deficiency Anemia in Childhood and Adolescence-Pathogenesis and Clinical Management Strategy

Many epidemiological studies and meta-analyses show that persistent Helicobacter pylori infection in the gastric mucosa can lead to iron deficiency or iron deficiency anemia (IDA), particularly in certain populations of children and adolescents. Moreover, it has been demonstrated that H. pylori infection can lead to and be closely associated with recurrent and/or refractory iron deficiency and IDA. However, the pathogenesis and specific risk factors leading to this clinical outcome in H. pylori-infected children remain poorly understood. In general, most of pediatric patients with H. pylori-associated IDA do not show evidence of overt blood loss due to gastrointestinal hemorrhagic lesions. In adult populations, H. pylori atrophic gastritis is reported to cause impaired iron absorption due to impaired gastric acid secretion, which, subsequently, results in IDA. However, significant gastric atrophy, and the resultant substantial reduction in gastric acid secretion, has not been shown in H. pylori-infected children. Recently, it has been hypothesized that competition between H. pylori and humans for iron availability in the upper gastrointestinal tract could lead to IDA. Many genes, including those encoding major outer membrane proteins (OMPs), are known to be involved in iron-uptake mechanisms in H. pylori. Recent studies have been published that describe H. pylori virulence factors, including specific OMP genes that may be associated with the pathogenesis of IDA. Daily iron demand substantively increases in children as they begin pubertal development starting with the associated growth spurt, and this important physiological mechanism may play a synergistic role for the microorganisms as a host pathogenetic factor of IDA. Like in the most recent pediatric guidelines, a test-and-treat strategy in H. pylori infection should be considered, especially for children and adolescents in whom IDA is recurrent or refractory to iron supplementation and other definitive causes have not been identified. This review will focus on providing the evidence that supports a clear biological plausibility for H. pylori infection and iron deficiency, as well as IDA.

Study of Serum Ferritin, Zinc, and Copper Levels in Children With Helicobacter pylori Gastritis and the Effect of the Treatment

OBJECTIVES

This study aimed to assess serum iron, zinc, and copper in symptomatic children with Helicobacter pylori infection, to correlate their serum levels with the degree of gastritis, and to evaluate the effect of H. pylori treatment on their levels.

METHODS

This study was carried out on 70 children with upper gastrointestinal tract symptoms. H. pylori infection was diagnosed by the H. pylori antigen test in the stool and histopathologic findings during upper gastrointestinal endoscopy. Patients were divided into 2 groups; H. pylori -positive and H. pylori -negative groups. Hemoglobin, serum ferritin, transferrin (sTfR), zinc, and copper were assessed in all included children.

RESULTS

The hemoglobin level, serum ferritin, and zinc were significantly lower in H. pylori -positive patients compared to H. pylori -negative patients. However, the serum copper level was comparable between the 2 groups. After treatment, the hemoglobin level, serum ferritin, and serum zinc significantly increased in H. pylori -positive patients, especially in those who responded to treatment compared to their levels before treatment. There was a significant negative correlation between the severity of histopathologic abnormalities and hemoglobin level, serum ferritin, and zinc levels, but a significant positive relation with sTfR concentrations in H. pylori -positive patients.

CONCLUSIONS

H. pylori -infected children had low serum ferritin and zinc levels but high sTfR level with no effect on serum copper levels. After treatment, hemoglobin, serum ferritin, and zinc levels significantly improved in H. pylori -positive patients. Gastric histologic findings correlated significantly with hemoglobin, serum ferritin, zinc, and sTfR levels.

Resolution of iron deficiency following successful eradication of Helicobacter pylori in children

AIM

To assess correlation between successful Helicobacter pylori (HP) eradication and resolution of iron deficiency in children, without iron supplementation.

METHODS

Medical records of children diagnosed with HP infection based on endoscopy were retrospectively reviewed. Among those with non-anaemic iron deficiency (NAID) or iron deficiency anaemia (IDA), haemoglobin, ferritin and CRP levels were compared prior and 6-9 months' post-successful HP eradication. Predictors of resolution of iron deficiency following HP eradication were assessed.

RESULTS

Among 60 included children (median age 14.8, IQR12.3-16 years; 62% males), 35% had IDA while the remaining 65% had NAID. Following successful HP eradication, iron normalised in 60% of patients with iron deficiency (ID), without iron supplementation. There were significant improvements in haemoglobin and ferritin concentrations following HP eradication with haemoglobin increasing from 12.3 g/dL to 13.0 g/dL and ferritin increasing from 6.3 μg/L to 15.1 μg/L (p < 0.001). In multiple logistic regression, older age was the only factor associated with resolution of anaemia following HP eradication (OR 1.65, 95% CI 1.16-2.35, p = 0.005).

CONCLUSION

Successful HP eradication could be helpful in improving iron status among children with refractory NAID or IDA. Older age may predict this outcome. Screening for HP might be considered in the workup of refractory IDA or ID.

The Association between Helicobacter Pylori Infection and Iron Deficiency Anemia in Children: A Systematic Review and Meta-Analysis

Objectives This study, comprising a systematic review and meta-analysis, was conducted to assess the association between Helicobacter pylori infection and the risk of iron deficiency anemia (IDA) in children.

Methods We followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Relevant published studies were searched in the databases. Retrieved studies were assessed for quality using the Modified Newcastle-Ottawa Scale for quality assessment. The “meta” package of statistical software “R 4.0.3 was used for statistical analysis.

Results Overall, 22 eligible studies (eight cross-sectional, six randomized control trials, five case-control, two surveys, and one cohort), including nine (40.9%) from Asia, four (18.1%) from America, four (18.1%) from Africa, four (18.1%) from Europe, and one (4.5%) from Australia with a total of 3,434 cases and 4,455 controls were included in this systematic review and meta-analysis. We found that H. pylori infection was associated with a high risk of IDA (odds ratio 1.70, 95% confidence interval 1.21 − 2.38) in a random-effects model. Meta-regression analysis showed that none of the investigated factors that may affect the prevalence of IDA reached statistical significance. There was statistically significant difference between results when studies were categorized according to the methods used to diagnose H. pylori and level of incomes based on World Bank classification. The GRADEpro Guideline Development Tool evidence for the risk of IDA was of a “moderate certainty.”

Conclusions This meta-analysis with a “moderate certainty” of evidence showed an association between H. pylori infection and a high risk of developing IDA in children.

Prevalence of Helicobacter pylori Infection among Anemic School-Age Children in Egypt: A Cross-Sectional Population-Based Study

Anemia and Helicobacter pylori infection in school-age children are important public health problems. The association between H. pylori infection and the development of anemia, especially iron deficiency anemia, has been previously studied and until now it is still a matter of argument. This study aimed to determine the prevalence of anemia and H. pylori infection among school-age children and to find the association between H. pylori infection and anemia in school-age children. We conducted this population-based cross-sectional study in six Egyptian primary schools over a 12-month-period, including 1,200 students from all grades who fulfilled the inclusion criteria. The study participants were subjected to the following: medical history, clinical examination, and laboratory investigations included complete blood count and H. pylori antigen in stool, and according to the level of hemoglobin (Hb), we divided the students into two groups; the anemic group with Hb level <11.5 g/dL and nonanemic group with Hb level ≥11.5 g/dL, and the serum ferritin levels were measured only for the anemic group as the best indicator for iron status. The overall prevalence of H. pylori infection was 25%. The overall prevalence of anemia was 13.25%, of which hypochromic microcytic anemia represented 87.4% of the anemic group, and the mean ferritin level in the anemic group was 18.56 ± 9.96 ng/mL. The prevalence of anemia among H. pylori-infected patients (62.3%) was significantly (p < 0.001) higher than in noninfected children (37.7%). In the anemic group, the mean ferritin level in H. pylori-infected children was significantly lower than the mean level in the noninfected children (p <0.001). Furthermore, the anemic group had a significantly higher incidence of H. pylori infection and a lower age (p <0.001) in comparison with the nonanemic group. The dominant type of anemia in H. pylori-infected children was the microcytic hypochromic anemia, with a significantly higher incidence in comparison to other types of anemia (p <0.001). The findings of this study demonstrate a significant association between H. pylori infection and anemia in school-aged children, especially iron deficiency anemia, as the incidence of H. pylori infection was greater in anemic children than in non-anemic children.

Helicobacter pylori among symptomatic Egyptian children: prevalence, risk factors, and effect on growth

AIM

This study was carried out to determine the prevalence and predictors of Helicobacter pylori (H. pylori) infection among symptomatic children and the effect on growth.

METHODS

A cross-sectional study was conducted in the Outpatient Clinics of the Gastroenterology Unit of the Pediatric Hospital, Cairo University. A total of 630 children complaining of any symptoms or signs suspicious of H. pylori infection were enrolled. Weight and height were measured for each child, and the standard deviation scores (Z-scores) for weight-for-age (WAZ), weight-for-height (WHZ), and height-for-age (HAZ) were calculated. H. pylori was diagnosed using a stool antigen test.

RESULTS

The overall prevalence of infection was 64.6%. Socio-demographic variables significantly associated with H. pylori were residence in Upper Egypt (P = 0.013) and rural areas (P = 0.004), illiteracy of mothers (P = 0.017), household crowding index ≥ 3 (P = 0.011), absence of pure water supply (P = 0.005), and eating from street vendors (P < 0.001). Values of WAZ [median, interquartile range (IQR) in infected = - 1.3(- 2.7 to - 0.4) and non-infected = - 0.7(- 2.1 to - 0.1), P < 0.001], HAZ (P = 0.036), and WHZ (P = 0.005) were significantly lower in children infected with H. pylori. After performing a backward logistic regression analysis, eating from street vendors (OR = 1.879, 95% CI 1.346-2.625, P < 0.001), absence of pure water supply (OR = 1.725, 95% CI 1.162-2.561, P = 0.007), and overcrowding (OR = 1.547, 95% CI 1.100-2.177, P = 0.012) remained the significant predictors of H. pylori infection.

CONCLUSION

A high prevalence of H. pylori infection among symptomatic children was detected. The extra-digestive effects of H. pylori were revealed in the form of affection of growth parameters and reduced levels of serum hemoglobin, iron, and ferritin.

Hepcidin correlates with interleukin-1β and interleukin-6 but not iron deficiency in children with Helicobacter pylori infection

BACKGROUND

Helicobacter pylori infection is associated with iron deficiency (ID) in children. Inflammatory cytokine reactions could influence the consequences of H. pylori infection. Hepcidin is an important regulator in iron homeostasis and could be induced by chronic inflammation. The relationship between hepcidin and cytokine levels in children infected with H. pylori remains controversial.

METHODS

Based on serology testing for anti-H. pylori IgG, participants (43 seropositive and 43 seronegative) aged 10-18 years were enrolled. Serum hepcidin levels and iron profiles, including iron, ferritin, and total iron-binding capacity, were measured. ID is defined as iron saturation less than 15%. Seropositive children were divided into low hepcidin (n = 22) and high hepcidin (n = 21) groups. IL-1β, IL-6, and IL-8 serum levels were compared.

RESULTS

Serum IL-1β and IL-6 levels were comparable between H. pylori seropositive and seronegative children, as were the median serum hepcidin levels (6.5 ng/mL versus 8.6 ng/mL; P = 0.1318). Median levels of serum iron, ferritin, and iron saturation were significantly lower in seropositive children with low hepcidin than in those with high hepcidin (P = 0.0123, P = 0.0001, and P = 0.0004, respectively). The prevalence of ID was significantly higher in those with low serum hepcidin levels (33.3% versus 4.5%; P = 0.015). Compared to the high hepcidin seropositive group, the low hepcidin group had significantly lower median serum levels of cytokines IL-1β and IL-6, but not IL-8 (P = 0.0151 and P = 0.0015, respectively).

CONCLUSIONS

Inflammatory cytokines IL-1β and IL-6, but not IL-8, might be associated with increased hepcidin levels among H. pylori-seropositive children. Further studies are needed to clarify the role of hepcidin.

Potential Association of IL1B Polymorphism With Iron Deficiency Risk in Childhood Helicobacter pylori Infection

OBJECTIVE

Helicobacter pylori infection occurs predominantly in childhood. Host immune response gene polymorphism is reported to affect the susceptibility to H pylori infection and the outcome of H pylori-related gastric cancer. Not all H pylori-infected patients, however, exhibit iron deficiency (ID). The relationship between host genetic polymorphisms and ID mediated by H pylori infection is not well understood.

METHODS

Subjects (n = 644) from the general population of age 10 to 18 years were divided into 2 groups based on serology testing for anti-H pylori IgG: seropositive study group; and seronegative control group. Five single nucleotide polymorphisms (SNPs) in IL1B (rs1143627 and rs16944), IL8 (rs4073), IL10 (rs1800896), and ABO (rs505922), were genotyped and the iron status of the 2 groups was compared.

RESULTS

The seroprevalence rate for H pylori was 10.7% in this study. Infected subjects were significantly older and had lower serum iron levels than uninfected subjects (P = 0.0195 and 0.0059, respectively). Multivariate analysis revealed a significantly higher frequency of the T allele of rs505922 (odds ratio [OR] = 6.128; P < 0.001) and lower frequency of the T allele of rs1143627 (OR = 0.846; P = 0.014) in seropositive subjects. Among 59 seropositive subjects, the T allele frequency of rs1143627 was significantly higher in those with ID (OR = 3.156; P = 0.043), compared with those without ID.

CONCLUSIONS

ABO (rs505922) and IL1B (rs1143627) may affect H pylori infection susceptibility, and IL1B (rs1143627) may also influence ID risk in infected children.

Review: Prevalence and dynamics of Helicobacter pylori infection during childhood

INTRODUCTION

Long-term persistent Helicobacter pylori infection has been associated with ulceropeptic disease and gastric cancer. Although H. pylori is predominantly acquired early in life, a clear understanding of infection dynamics during childhood has been obfuscated by the diversity of populations evaluated, study designs, and methods used.

AIM

Update understanding of true prevalence of H. pylori infection during childhood, based on a critical analysis of the literature published in the past 5 years.

METHODS

Comprehensive review and meta-analysis of original studies published from 2011 to 2016.

RESULTS

A MEDLINE^® /PubMed^® search on May 1, 2016, using the terms pylori and children, and subsequent exclusion, based on abstract review using predefined criteria, resulted in 261 citations. An Embase^® search with the same criteria added an additional 8 citations. In healthy children, meta-analysis estimated an overall seroprevalence rate of 33% (95% CI: 27%-38%). Seven healthy cohort studies using noninvasive direct detection methods showed infection prevalence estimates ranging from 20% to 50% in children ≤5 and 38% to 79% in children >5 years. The probability of infection persistence after a first positive sample ranged from 49% to 95%. Model estimates of cross-sectional direct detection studies in asymptomatic children indicated a prevalence of 37% (95% CI: 30%-44%). Seroprevalence, but not direct detection rates increased with age; both decreased with increasing income. The model estimate based on cross-sectional studies in symptomatic children was 39% (95% CI: 35%-43%).

CONCLUSIONS

The prevalence of H. pylori infection varied widely in the studies included here; nevertheless, model estimates by detection type were similar, suggesting that overall, one-third of children worldwide are or have been infected. The few cohort and longitudinal studies available show variability, but most studies, show infection rates over 30%. Rather surprisingly, overall infection prevalence in symptomatic children was only slightly higher, around 40%. Studies including only one positive stool sample should be interpreted with caution as spontaneous clearance can occur.

An updated systematic review and meta-analysis on the association between Helicobacter pylori infection and iron deficiency anemia

BACKGROUND

We conducted an updated systematic review and meta-analysis to examine the prevalence of depleted iron stores among persons infected with Helicobacter pylori compared to uninfected ones. We also assessed the impact of anti-H. pylori eradication therapy plus iron therapy on ferritin and hemoglobin levels compared to iron therapy alone.

METHODS

A literature search was conducted using the databases Medline, the Cochrane Library, Cochrane Central Register of Controlled Trials, EMBASE, and the Science Citation Index Expanded. Observational studies with methodological quality score of 13 (median score) and above, on a scale of 0-16, and all randomized controlled trials (RCTs) were eligible for the meta-analyses. Pooled point estimates and 95% confidence intervals (CI) were obtained using the random effects model.

RESULTS

Compared to uninfected persons, H. pylori-infected individuals showed increased likelihood of iron deficiency anemia (14 observational studies); pooled OR 1.72 (95% CI 1.23-2.42); iron deficiency (pooled OR 1.33; 95% CI 1.15-1.54; 30 studies); and anemia (pooled OR 1.15; 95% CI 1.00-1.32; 23 studies). Meta-analyses of seven RCTs showed increased ferritin, standardized mean difference (SMD) 0.53 (95% 0.21-0.85), but not hemoglobin, SMD 0.36 (95% -0.07 to 0.78), Pv=.1, following anti-H. pylori eradication therapy plus iron therapy as compared with iron therapy alone. Significant heterogeneity was found among studies, as well as evidence of publication bias.

CONCLUSIONS

Current evidence indicates increased likelihood of depleted iron stores in relation to H. pylori infection. H. pylori eradication therapy, added to iron therapy, might be beneficial in increasing ferritin and hemoglobin levels.

Folate and Inflammatory Markers Moderate the Association Between Helicobacter pylori Exposure and Cognitive Function in US Adults

BACKGROUND

Helicobacter pylori (H. pylori) infection is associated with cognitive deficits in humans, an association potentially mediated or moderated by folate concentration or inflammation.

MATERIALS AND METHODS

We used the National Health and Nutrition Examination Survey (NHANES) datasets to examine whether folate concentration or inflammation mediates or moderates the relationship between H. pylori and cognitive function. Models were performed using linear, Poisson, and zero-inflated Poisson regression, and we performed separate analyses for groups aged 20-59 and 60-90 years with sample sizes ranging from 700 to 1700.

RESULTS

We did not find evidence of mediation in either age group. In the 20- to 59-year group, interactions between H. pylori and ferritin (p values ranging from .004 to .039) were associated with worse processing speed, better working memory, and worse reaction time. Interactions between H. pylori and fibrinogen (p values ranging from .023 to .045), C-reactive protein (CRP) (p = .023), and the inflammatory index (p = .045) were associated with worse processing speed. In 60- to 90-year-olds, H. pylori interacted with ferritin and the inflammatory index to predict fewer mathematical errors (p values of .036 and .023). Interactions with folate (p values of .016 and .006) and C-reactive protein (p values ranging from <.001 to .048) were inconsistent in directionality.

CONCLUSIONS

In this dataset, representative of the US population, inflammation and folate concentrations moderated but did not mediate the association between H. pylori seropositivity and cognition.

Helicobacter pylori infection and extragastric disorders in children: a critical update

Helicobacter pylori (H. pylori) is a highly prevalent, serious and chronic infection that has been associated causally with a diverse spectrum of extragastric disorders including iron deficiency anemia, chronic idiopathic thrombocytopenic purpura, growth retardation, and diabetes mellitus. The inverse relation of H. pylori prevalence and the increase in allergies, as reported from epidemiological studies, has stimulated research for elucidating potential underlying pathophysiological mechanisms. Although H. pylori is most frequently acquired during childhood in both developed and developing countries, clinicians are less familiar with the pediatric literature in the field. A better understanding of the H. pylori disease spectrum in childhood should lead to clearer recommendations about testing for and treating H. pylori infection in children who are more likely to develop clinical sequelae. A further clinical challenge is whether the progressive decrease of H. pylori in the last decades, abetted by modern clinical practices, may have other health consequences.

Unintended consequences of Helicobacter pylori infection in children in developing countries: iron deficiency, diarrhea, and growth retardation

Helicobacter pylori infection is predominantly acquired early in life. The prevalence of the infection in childhood is low in developed countries, whereas in developing countries most children are infected by 10 y of age. In poor resource settings, where malnutrition, parasitic/enteropathogen and H. pylori infection co-exist in young children, H. pylori might have potentially more diverse clinical outcomes. This paper reviews the impact of childhood H. pylori infection in developing countries that should now be the urgent focus of future research. The extra-gastric manifestations in early H. pylori infection in infants in poor resource settings might be a consequence of the infection associated initial hypochlorhydria. The potential role of H. pylori infection on iron deficiency, growth impairment, diarrheal disease, malabsorption and cognitive function is discussed in this review.

Extragastric manifestations of Helicobacter pylori infection

In the last year, different diseases possibly linked to Helicobacter pylori infection but localized outside of the stomach have been investigated. There are, in fact, several studies concerning cardiovascular diseases, hematologic disorders, neurologic diseases, metabolic, hepatobiliary diseases, and other conditions. Some of those studies, such as those on sideropenic anemia and idiopathic thrombocytopenic purpura, are quite large and well conducted, while in other cases there are just small or isolated studies or even case reports. Nonetheless, there is much interest among researchers all over the world for such a topic as demonstrated by the large number of studies published in the last year.

Epidemiology of Helicobacter pylori infection and public health implications

This review summarizes studies on the epidemiology and public health implications of Helicobacter pylori published in peer-reviewed journals from April 2010 through March 2011. Prevalence rates vary widely between different geographical regions and ethnic groups. An interesting study from the USA identified the degree of African ancestry as an independent predictor of H. pylori infection. Two studies have demonstrated early childhood as the period of transmission of infection and identified an infected sibling as an important risk factor. An oral-oral route of spread has been substantiated with several studies showing the presence of H. pylori in the oral cavity. Studies have shown the presence of H. pylori in drinking water and the role of poor living conditions and sanitation in H. pylori infection, supporting an oral-fecal route of spread. Screening for H. pylori as a gastric cancer pre-screening strategy has been described in Japan, and the importance of H. pylori eradication as a gastric cancer-prevention strategy has now been further emphasized in Japanese guidelines. Two studies have shown a decrease in the burden of dyspepsia and peptic ulcer disease with H. pylori eradication.

Epidemiology of Helicobacter pylori infection and public health implications

This review summarizes studies on the epidemiology and public health implications of Helicobacter pylori published in peer-reviewed journals from April 2010 through March 2011. Prevalence rates vary widely between different geographical regions and ethnic groups. An interesting study from the USA identified the degree of African ancestry as an independent predictor of H. pylori infection. Two studies have demonstrated early childhood as the period of transmission of infection and identified an infected sibling as an important risk factor. An oral-oral route of spread has been substantiated with several studies showing the presence of H. pylori in the oral cavity. Studies have shown the presence of H. pylori in drinking water and the role of poor living conditions and sanitation in H. pylori infection, supporting an oral-fecal route of spread. Screening for H. pylori as a gastric cancer pre-screening strategy has been described in Japan, and the importance of H. pylori eradication as a gastric cancer-prevention strategy has now been further emphasized in Japanese guidelines. Two studies have shown a decrease in the burden of dyspepsia and peptic ulcer disease with H. pylori eradication.

Helicobacter pylori in pediatrics

This article reviewed the important publications on Helicobacter pylori research with children between April 2010 and March 2011. The most interesting studies in the last year lend further weight to the evidence for vertical transmission of H. pylori. The discovery of a potential role for jhp0562, the gene which encodes for the cell envelope protein glycosyltransferase, in the progression to peptic ulcer disease is also very interesting as it may provide a novel way to distinguish children at risk of peptic ulcer disease from those who are not, and so determine those who requires treatment to eradicate H. pylori. The rise in non-H. pylori-associated ulcers and erosions continues to be reported with no apparent risk factors for these ulcers identified to date. High levels of treatment failure continue to be reported, and there remains an urgent need for more effective treatment regimes for children.