Controlled, household-randomized, open-label trial of the effect of treatment of Helicobacter pylori infection on iron deficiency among children in rural Alaska: results at 40 months

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.

Is Helicobacter Pylori a Reason for Unexplained Iron Deficiency Anemia: A Systematic Review

Iron deficiency anemia (IDA) is a worldwide public health problem affecting millions, with developing nations accruing a significant disease burden. Helicobacter pylori (H. pylori) has been proposed in many studies as a causative factor for unexplained iron deficiency anemia. In this systematic review, we searched PubMed, Google Scholar, and ScienceDirect to come up with five cross-sectional studies and five Randomized Controlled Trials (RCTs), which evaluated the association between H. pylori and unexplained iron deficiency anemia and the response of IDA to anti-H. pylori therapy. H. pylori eradication therapy included triple therapy (proton pump inhibitor, clarithromycin, amoxicillin) or quadruple therapy (proton pump inhibitor, bismuth, metronidazole, tetracycline) for 10-14 days. Quadruple therapy was used if there is a penicillin allergy or a local antibiotic resistance level of more than 15% to clarithromycin. The cross-sectional studies concluded that H. pylori infection was associated with low serum ferritin levels. The RCTs confirmed that H. pylori are associated with iron deficiency anemia by demonstrating improvement in markers of iron status (ferritin, hemoglobin, Mean Corpuscular Volume (MCV), serum transferrin receptor levels) with H. pylori eradication therapy. In a nutshell, this systematic review concludes that H. pylori testing and treatment must be considered as a differential diagnosis of unexplained IDA in all age groups and serves as a benchmark for more randomized clinical trials to prove causation.

The Relationship between Anemia and Helicobacter Pylori Infection in Children

(1) Background: Many studies suggest that Helicobacter pylori (H. pylori) infection is associated with a higher prevalence of anemia. The aim of this study is to explore this fact for a pediatric population from the northeast of Romania; (2) Methods: A correlational retrospective study between infection with H. pylori and anemia was performed on a group of 542 children in a pediatric gastroenterology regional center in Northeast Romania; (3) Results: Out of 542 children with confirmed H. pylori infection, microcytic hypochromic anemia was present in 48 children, of whom 7 (14.5%) also had iron deficiency.; (4) Conclusions: The study results demonstrate a significant association of H. pylori infection with iron-deficiency anemia and iron deficiency in children in accordance with the results established in the published literature. Although the direct relationship between them it is not clear yet, prevention represents one of the first clinical measures that need to be implemented when encountering a refractory moderate to severe iron-deficiency anemia and, especially, when associated with gastrointestinal tract symptoms.

Unexplained iron deficiency anemia: does Helicobacter pylori have a role to play?

Background and aim

Testing for Helicobacter pylori (Hp) infection is recommended for work-up of unexplained iron deficiency anemia (IDA), although the evidence supporting this recommendation is scant. The aim of this study was to investigate the association between Hp infection and unexplained iron deficiency (ID) or IDA in the older adult population without significant upper gastrointestinal source of blood loss.

Methods

Retrospective single-center cohort study; 523 out of 1253 consecutive patients who underwent esophagogastroduodenoscopy with no significant upper and/or lower gastrointestinal source for blood loss or risk factors for IDA. Comparisons were made between the Hp-positive and Hp-negative groups using Fisher exact test, chi-square test and Student’s t-test. Univariate and multiple logistic regression analyses were used to identify significant risk factors associated with ID and IDA.

Results

One hundred and three subjects (19.7%) had Hp infection and 420 (80.3%) were negative for Hp. Sixty-eight (22.1%) out of 307 subjects with available serum iron profile had unexplained ID and 28 (5.4%) out of 510 subjects with available hemoglobin profile had unexplained IDA. No association was found between ID/IDA and Hp infection in univariate and multiple logistic regression analyses.

Conclusion

We found no association between unexplained ID or IDA and Hp infection in older adult population without peptic ulcer disease or significant upper gastrointestinal source of blood loss.

Association of anaemia with Helicobacter pylori infection: a retrospective study

The role of Helicobacter pylori (H. pylori) infection in haematological system diseases is not well understood. We conducted this retrospective study to explore the association between H. pylori infection and anaemia in the Chinese population. This retrospective study was performed in Aerospace Center Hospital in Beijing. We derived the data from the registration system of the physical population between 2012-2016. Logistic regression models were used to explore the association between H. pylori infection and anaemia. Among 17,791 subjects, there were 7,804 (43.9%) subjects with H. pylori infection and 950 (5.3%) with anaemia. The prevalence of anaemia in the H. pylori (+) group was significantly higher than in the H. pylori (-) group after adjusting for age, sex, marriage, underlying diseases and body mass index. Compared to H. pylori (-), the OR of H. pylori (+) was 1.39 for moderate-to-severe anaemia and 1.05 for mild anaemia. The level of haemoglobin was lower in the H. pylori (+) group than in the H. pylori (-) group. This study indicates that H. pylori infection may be related to anaemia and haemoglobin level in the Chinese population.

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.

Effect of early and current Helicobacter pylori infection on the risk of anaemia in 6.5-year-old Ethiopian children

BACKGROUND

Epidemiological and clinical studies in high income countries have suggested that Helicobacter pylori (H. pylori) may cause anaemia, but evidence is lacking from low income countries.We examined associations between H. pylori infection in early childhood and anaemia at the age of 6.5 years in an Ethiopian birth cohort.

METHODS

In 2011/12, 856 children (85.1 % of the 1006 original singletons in a population-based birth cohort) were followed up at age six and half. An interviewer-led questionnaire administered to mothers provided information on demographic and lifestyle variables. Haemoglobin level and red cell indices were examined using an automated haematological analyzer (Cell Dyn 1800, Abbott, USA), and stool samples analyzed for H. pylori antigen. The independent effects of H. pylori infection (measured at age 3.5 and 6.5 years) on anaemia, haemoglobin level, and red cell indices (measured at age 6.5 years) were determined using multiple logistic and linear regression.

RESULTS

The prevalence of anemia was 34.8 % (257/739), and the mean (SD) haemoglobin concentration was 11.8 (1.1) gm/dl. Current H. pylori infection at age 6.5 years was positively, though not significantly related to prevalence of anaemia (adjusted OR, 95 % CI, 1.15; 0.69, 1.93, p = 0.59). Any H. pylori infection up to age 6.5 years was significantly associated with an increased risk of anaemia at age 6.5 (adjusted OR, 95 % CI, 1.68; 1.22, 2.32, p = 0.01). A significant reduction in haemoglobin concentration and red cell indices was also observed among children who had any H. pylori infection up to age 6.5 (Hb adjusted β = -0.19, 95 % CI, -0.35 to -0.03, p = 0.01; MCV adjusted β = -2.22, 95 % CI, -3.43 to -1.01, p = 0.01; MCH adjusted β = -0.63, 95 % CI, -1.15 to - 0.12, p = 0.01; and MCHC adjusted β = -0.67, 95 % CI, -1.21 to -0.14, p = 0.01), respectively.

CONCLUSION

This study provides further evidence from a low income country that any H. pylori infection up to age 6.5 is associated with higher prevalence of anaemia, and reduction of haemoglobin level and red cell indices at age 6.5.

Complex anemia in tuberculosis: the need to consider causes and timing when designing interventions

BACKGROUND

Anemia is common in tuberculosis, and multiple etiologies necessitate targeted interventions. The proportion of iron-responsive anemia due to iron deficiency compared with iron-unresponsive anemia due to impaired iron absorption/redistribution from tuberculosis-associated immune activation or inflammation is unknown. This impedes selection of safe and effective treatment and appropriate intervention timing.

METHODS

Baseline hemoglobin, ferritin, hepcidin, soluble transferrin receptor (sTfR), and transferrin were measured in 45 patients with confirmed pulmonary tuberculosis (cases), 47 tuberculin skin test (TST)-positive controls, and 39 TST-negative controls in The Gambia. Tuberculosis cases were additionally followed 2 and 6 months after tuberculosis treatment initiation. Mutually exclusive anemia categories based on iron biomarker concentrations were iron deficiency anemia (IDA), anemia of inflammation (AI), and multifactorial anemia (IDA+AI).

RESULTS

Anemia was more frequent in tuberculosis cases (67%) than in TST-positive (36%) or TST-negative (21%) controls. AI was the predominant anemia at tuberculosis diagnosis, declining from 36% to 8% after 6 months of treatment; however, a corresponding reduction was not evident for anemia with iron-responsive components (IDA, IDA+AI). Iron biomarkers discriminated between active tuberculosis and TST-positive or TST-negative controls, as well as between active untreated and treated tuberculosis. This was most noticeable for hepcidin, which decreased from a median of 84.0 ng/mL at diagnosis to 9.7 ng/mL after 2 months (P < .001).

CONCLUSIONS

Tuberculosis chemotherapy is associated with significant reductions in AI, but IDA and IDA+AI remain unresolved. Iron-based interventions are needed for IDA and IDA+AI, and monitoring of iron biomarkers reveals a window for intervention opening as early as 2 months into tuberculosis treatment.

[Guidelines for the diagnosis and treatment of Helicobacter pylori infection in Korea, 2013 revised edition]

Since the Korean College of Helicobacter and Upper Gastrointestinal Research has first developed the guideline for the diagnosis and treatment of Helicobacter pylori infection in 1998, the revised guideline was proposed in 2009 by the same group. Although the revised guideline was made by comprehensive review of previous articles and consensus of authoritative expert opinions, the evidence-based developmental process was not applied in the revision of the guideline. This new guideline has been revised especially in terms of changes in the indication and treatment of H. pylori infection in Korea, and developed by the adaptation process as evidence-based method; 6 guidelines were retrieved by systematic review and the Appraisal of Guidelines for Research and Evaluation (AGREE) II process, 21 statements were made with grading system and revised by modified Delphi method. After revision, 11 statements for the indication of test and treatment, 4 statements for the diagnosis and 4 statements for the treatment have been developed, respectively. The revised guideline has been reviewed by external experts before the official endorsement, and will be disseminated for usual clinical practice in Korea. Also, the scheduled update and revision of the guideline will be made periodically.

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.

The role of Helicobacter pylori infection in hematological disorders

Helicobacter pylori (H. pylori) is a Gram-negative spiral bacterium, classified as a carcinogen of class I, according to the World Health Organization (WHO). The infection is a major cause of gastritis, gastric and duodenal ulcer disease and increases the risk of gastric cancer. It has been implicated in the pathogenesis of several gastrointestinal, systemic or hematological diseases. The present review aims in deciphering the role of the bacterium in hematological disorders, increasing the awareness of gastroenterologists, hematologists and internal medicine practitioners, regarding the bacterium-associated hematological diseases. The efficacy of H. pylori eradication in increasing the platelet count in adult patients with primary immune thrombocytopenia (ITP) has been confirmed, linking the infection with the disease. Moreover, as the bacterium causes iron deficiency anemia (IDA) by several mechanisms, recent guidelines indicate H. pylori infection (Hp-I) to be sought in IDA patients if histology is negative and to be eradicated if present. Furthermore, it has been widely recognized that anti-H. pylori treatment causes regression of the low-grade B-cell gastric MALT lymphomas. Despite the well established associations of Hp-I with the aforementioned hematological disorders, we highlight the possible role of the infection to other hematological diseases or conditions such as non-Hodgkin lymphomas of the stomach, monoclonal gammopathy of undetermined significance, megaloblastic anemia and myelodysplastic syndromes. We finally underline the elevated risk of childhood leukemia and of hemorrhage in patients with coagulation disorders, due to the infection.

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.

What do we know about benefits of H. pylori treatment in childhood?

Policy analysis shows that H. pylori test and treat strategies targeting adults at moderate to high risk of H. pylori-induced disease is likely to be cost-effective for preventing digestive diseases responsible for a large global disease burden. Little is known, however, about health benefits to children from eliminating this infection. We conducted a systematic review of the evidence regarding health benefits to children from treatment to eliminate H. pylori infection.   We systematically searched Ovid MEDLINE for pertinent review articles published through 2012. We excluded reviews focused on treatment efficacy and scrutinized reference lists of selected reviews to identify additional eligible reviews. Fifteen reviews met specified inclusion criteria. Overall, they show that few reported studies investigating pediatric health effects of treatment for H. pylori infection were well designed with adequate statistical power. Thus, there is insufficient evidence for drawing conclusions about health benefits to children from treatment to eliminate H. pylori infection.

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.

The effect of Helicobacter pylori infection on iron stores and iron deficiency in urban Alaska Native adults

BACKGROUND

Helicobacter pylori (H. pylori) infection has been correlated with low serum ferritin and iron deficiency. As a secondary analysis of a study of H. pylori reinfection, we investigated the association of H. pylori infection and the effect of its eradication on serum ferritin and iron deficiency.

METHODS

Alaska Native adults undergoing esophagogastroduodenoscopy had sera collected and a (13) C urea breath test (UBT) was performed. Those H. pylori positive were treated with an antibiotic regimen; those who tested negative 2 months after treatment were evaluated at 4, 6, 12, and 24 months by UBT and serum ferritin with an immunoradiometric assay. We excluded persons from further analysis if they were prescribed iron by their provider.

RESULTS

We measured serum ferritin for 241 persons; 121/241 were H. pylori positive. The geometric mean ferritin (GMF) for persons with and without H. pylori infection was 37 μg/L and 50 μg/L, respectively (p = .04). At enrollment, 19/121 H. pylori-positive persons had iron deficiency compared with 8/120 H. pylori negative (p = .02). Among 66 persons tested at 24 months, the GMF was higher at 24 months (49.6 μg/L) versus enrollment (36.5 μg/L; p = .02). Six of 11 persons with iron deficiency at enrollment no longer had iron deficiency and had a higher GMF (p = .02) 24 months after treatment.

CONCLUSIONS

H. pylori infection was correlated with lower serum ferritin and iron deficiency. After H. pylori eradication, serum ferritin increased and approximately half of persons resolved their iron deficiency. Testing for H. pylori infection and subsequent treatment of those positive could be considered in persons with unexplained iron deficiency.

Diagnostic accuracy of tests for Helicobacter pylori in an Alaska Native population

AIM: To evaluate the accuracy of two non-invasive tests in a population of Alaska Native persons. High rates of Helicobacter pylori (H. pylori) infection, H. pylori treatment failure, and gastric cancer in this population necessitate documentation of infection status at multiple time points over a patient’s life.

METHODS: In 280 patients undergoing endoscopy, H. pylori was diagnosed by culture, histology, rapid urease test, ¹³C urea breath test (UBT), and immunoglobulin G antibodies to H. pylori in serum. The performances of ¹³C-UBT and antibody test were compared to a gold standard defined by a positive H. pylori test by culture or, in case of a negative culture result, by positive histology and a positive rapid urease test.

RESULTS: The sensitivity and specificity of the ¹³C-UBT were 93% and 88%, respectively, relative to the gold standard. The antibody test had an equivalent sensitivity of 93% with a reduced specificity of 68%. The false positive results for the antibody test were associated with previous treatment for an H. pylori infection [relative risk (RR) = 2.8]. High levels of antibodies to H. pylori were associated with chronic gastritis and male gender, while high scores in the ¹³C-UBT test were associated with older age and with the H. pylori bacteria load on histological examination (RR = 4.4).

CONCLUSION: The ¹³C-UBT outperformed the antibody test for H. pylori and could be used when a non-invasive test is clinically necessary to document treatment outcome or when monitoring for reinfection.

Helicobacter pylori eradication and change in markers of iron stores among non-iron-deficient children in El Paso, Texas: an etiologic intervention study

OBJECTIVES

We assessed whether Helicobacter pylori eradication was followed by changes in iron stores among non-iron-deficient children.

MATERIALS AND METHODS

Double-blind randomized intervention trial on 110 asymptomatic 3- to 10-year-olds with H pylori infection assigned to any of the following 4 arms: both quadruple eradication and iron supplementation, either quadruple sequential eradication or iron supplementation, or placebo only. Hemoglobin, transferrin saturation, and serum ferritin were measured at baseline and 8 months later to assess changes according to study arm, H pylori infection status at ≥45 days, and cytotoxin-associated gene product A status.

RESULTS

Intent-to-treat (n = 110) and per-protocol (n = 90) analyses revealed no differences across study arms in changes of iron stores. However, we found that those who had their infection eradicated had a 3-fold increased average change from baseline serum ferritin compared with that of children who remained infected (P < 0.05). Eradication of infection by cytotoxin-associated gene product A negative strains was associated with a larger ferritin increase.

CONCLUSIONS

In this double-blind randomized trial, the first among non-iron-deficient, asymptomatic H pylori-infected children living in the contiguous United States, we found no effect of H pylori eradication regarding changes in iron stores. However, those who had their infection eradicated at follow-up had a significantly larger increase in serum ferritin from baseline.

Consequences of Helicobacter pylori infection in children

Although evidence is emerging that the prevalence of Helicobacter pylori (H. pylori) is declining in all age groups, the understanding of its disease spectrum continues to evolve. If untreated, H. pylori infection is lifelong. Although H. pylori typically colonizes the human stomach for many decades without adverse consequences, children infected with H. pylori can manifest gastrointestinal diseases. Controversy persists regarding testing (and treating) for H. pylori infection in children with recurrent abdominal pain, chronic idiopathic thrombocytopenia, and poor growth. There is evidence of the role of H. pylori in childhood iron deficiency anemia, but the results are not conclusive. The possibility of an inverse relationship between H. pylori and gastroesophageal reflux disease, as well as childhood asthma, remains a controversial question. 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.

Is the association between Helicobacter pylori infection and anemia age dependent?

BACKGROUND

The relationship between H. pylori infection and anemia in childhood is still unclear. The aim of the study was to examine the association between H. pylori infection and anemia or iron deficiency in school-age children and in infants.

MATERIALS AND METHODS

Six- to 9-year-old Israeli Arab children (N = 202) and infants (N = 197) were examined for hemoglobin and ferritin levels. ELISA was used to detect H. pylori antigens in stool specimens collected from the participants. Household characteristics were obtained through personal interviews with the mothers.

RESULTS

The prevalence of anemia was 15.5 versus 5.5% in H. pylori-positive and -negative school-age children, respectively and 34.5 versus 29.8% in H. pylori-positive and -negative infants, respectively. The Mantel-Haenszel age-adjusted prevalence ratio (PR) and 95% confidence intervals (CIs) were 1.6 (95%CI 1.0, 2.6). In multivariate analysis controlling for socioeconomic variables, H. pylori infection was associated with 2.8 higher prevalence of anemia only in school-age children: adjusted PR 2.8 (95% CI 0.9, 9.3). The adjusted mean difference in hemoglobin levels between H. pylori infected school-age children and uninfected ones was -0.372 gr/dL (95% CI -0.704, -0.039) (p = .04). The respective mean ferritin difference was -6.74 μg/L (95% CI -13.38, -.011) (p = .04). Such differences were not found in infants.

CONCLUSIONS

H. pylori infection is associated with higher prevalence of anemia in school-age children independently of socioeconomic variables. Such association was not observed in infants. These findings are of clinical and public health importance.

Helicobacter pylori and iron-deficiency anemia in adolescents in Brazil

AIM

The aim of the study was to evaluate the association between Helicobacter pylori infection and iron deficiency (ID) in adolescents attending a public school.

PATIENTS AND METHODS

From March to June 2001, a cross-sectional study was conducted among adolescents (10-16 years) enrolled in a single public school in São Paulo, Brazil. Of 400 eligible students, 195 agreed to participate, but 1 was excluded due to sickle cell disease. A blood sample was collected from each subject to measure hemoglobin and ferritin. H pylori status was investigated with the C-urea breath test. All of the subjects with either anemia or ID were given iron therapy.

RESULTS

H pylori prevalence was 40.7% (79/194), being higher in male subjects (45/90 vs 34/104, P = 0.014). There was no relation between infection and nutritional status. Abnormally low serum ferritin was observed in 12 subjects, half of whom were positive for H pylori (odds ratio [OR] 1.49, 95% confidence interval [CI] 0.38-5.81). The median serum ferritin was 33.6 ng/mL (interquartile range 23.9-50.9) in infected subjects and 35.1 ng/mL (interquartile range 23.7-53.9) in uninfected subjects. Anemia was detected in 2% (4/194) of the students, half of whom were infected (OR 1.47, 95% CI 0.1-20.6). The mean hemoglobin value in infected subjects was 13.83 g/dL ± 1.02 versus 14 g/dL ± 1.06 in uninfected subjects.

CONCLUSIONS

The study was not able to find a relation between H pylori infection and ID or anemia.

A short review of malabsorption and anemia

Anemia is a frequent finding in most diseases which cause malabsorption. The most frequent etiology is the combination of iron and vitamin B12 deficiency. Celiac disease is frequently diagnosed in patients referred for evaluation of iron deficiency anemia (IDA), being reported in 1.8%-14.6% of patients. Therefore, duodenal biopsies should be taken during endoscopy if no obvious cause of iron deficiency (ID) can be found. Cobalamin deficiency occurs frequently among elderly patients, but it is often unrecognized because the clinical manifestations are subtle; it is caused primarily by food-cobalamin malabsorption and pernicious anemia. The classic treatment of cobalamin deficiency has been parenteral administration of the vitamin. Recent data suggest that alternative routes of cobalamin administration (oral and nasal) may be useful in some cases. Anemia is a frequent complication of gastrectomy, and has been often described after bariatric surgery. It has been shown that banding procedures which maintain digestive continuity with the antrum and duodenum are associated with low rates of ID. Helicobacter pylori (H pylori) infection may be considered as a risk factor for IDA, mainly in groups with high demands for iron, such as some children and adolescents. Further controlled trials are needed before making solid recommendations about H pylori eradication in these cases.

Helicobacters and extragastric diseases

For two decades, Helicobacter pylori has been considered as the culprit in many extragastric manifestations. However, for several of these supposed associations the hypothesis of an etiological role has not yet been fully investigated. This may be due to a series of factors linked to the epidemiological features of the studies and to the diseases investigated. This review attempts to highlight the main reported associations of H. pylori with extragastric manifestations during the last year. The most convincing data arise in the field of idiopathic thrombocytopenic purpura (ITP) and sideropenic anemia. Long-term follow-up studies have shown that 50% of subjects with ITP maintain a hematological response after H. pylori eradication. There is also growing evidence of the role of H. pylori in other diseases, including ischemic heart disease even though results are not conclusive.

Helicobacter pylori infection in pediatrics

his review summarizes the articles published on Helicobacter pylori infection in children between April 2008 and March 2009. Recent evidence highlights the decreasing prevalence trend of H. pylori infection and supports both intrafamilial and extrafamilial transmission. The association with various symptoms is still being debated. Interestingly, H. pylori infection seems inversely associated with allergic diseases. Monoclonal stool antigen tests are widely used and accurate for the diagnosis of H. pylori infection, but less accurate in young children. The new biprobe real-time PCR assay applied to stools showed a poor sensitivity in children. Using the urea hydrolysis rate next to the delta over baseline values, the (13)C-urea breath test provides excellent results for all age children, even for young children. Treatment of H. pylori infection remains a challenge, considering suboptimal efficacy of current therapy. Among emerging alternatives, sequential treatment appears promising. The adjunction of probiotics to conventional regimens, although eliciting great interest, has shown limited therapeutic benefit.