Persisting Helicobacter antibodies in Finnish children and adolescents between two and twenty years of age

A 5-year trend of Helicobacter pylori seroprevalence among dyspeptic patients at Bahir Dar Felege Hiwot Referral Hospital, Northwest Ethiopia

Background

Helicobacter pylori infection is a major public health problem affecting half of the world's population. The prevalence of H. pylori varies in different societies and geographical locations. Thus, timely information on H. pylori epidemiology is critical to combat this infection. This study aimed to determine the seroprevalence and trend of H. pylori infection over a period of 5 years among dyspeptic patients at Bahir Dar Felege Hiwot Referral Hospital, Northwest Ethiopia.

Methods

A retrospective analysis of consecutive dyspeptic patients' records covering the period between January 2009 and December 2013 was conducted. The hospital laboratory generated the data by a serological method of detecting the antibodies for H. pylori from serum by a one-step rapid test device. Chi-square analysis was used to identify significant predictors. A P-value of <0.05 was considered as statistically significant.

Results

Among all the study subjects, 2,733 (41.6%) were found to be seropositive. The seroprevalence was significantly higher in males (43.2%) than in females (39.9%) (χ²=9; P=0.002). In terms of age groups of the patients, high rates of H. pylori were found among the participants older than 60 years (57%) (χ²=36.6; P≤0.00001). The trend analysis of H. pylori prevalence revealed a fluctuating prevalence; it was 44.5% in the year 2009 and decreased to 34% and 40% in the years 2010 and 2011, respectively. However, there was an increment to 52.5% in the year 2012, and then it decreased to 30.2% in the year 2013.

Conclusion

This study showed high seroprevalence of H. pylori among the dyspeptic patients in Bahir Dar Felege Hiwot Referral Hospital. The trend of the seroprevalence varied from year to year in the 5 consecutive years. Considering this, designing appropriate prevention and control strategies is mandatory.

Rate ofHelicobacter pyloriInfection in Children and Clonality of Taiwan Strains

The infection rate of Helicobacter pylori in children from < 1 to 17 years old was investigated. Three techniques, namely culture, CLO test, and PCR, were employed to check the presence or absence of the organism in the antrum of the stomach. Several PCR positives without viable cultures were observed in babies of less than one year old. On the other hand, only two viable cultures were obtained from toddlers of less than two years old. The percentage of positive cultures steadily increased from 8% (3 of 42 cases) in the 0-4 years old age group to 32% (32 of 99 cases) in the 13-17 years old age group. A steady increase also was observed in the result of the CLO test. In PCR, the percentage of positives was greatly higher than that seen with the culture or CLO test. The rate of PCR positives also showed an increase with age but of a much slower rate. The overall infection rate in 295 children was 22% (64 of 295 cases) positive with culture and 76% (225 of 295 cases) with PCR, in contrast to 85% (40 of 49 cases) and 92% (43 of 47 cases), respectively, in adults. The urease activity of the H. pylori derived from children was much lower than that derived from adults (P < 0.001). Taken together, these results suggest that a child might be repeatedly infected and some infecting strains eventually might obtain a steady infection, perhaps by a strain of higher virulence such as higher urease activity. The base variations in the nucleotide sequences did not correlate to the varied urease activities or to the age of the child. The sequences, however, indicated that there were two types of strains. The strains in Taiwan appeared to be derived from the French type strain and not the English type strain. The amino acid sequences of the ureA and the phylogenetic relationship of the 29 strains indicated that the strains in Taiwan are rapidly evolving into a unique clone.

Sex hormones, hormonal interventions, and gastric cancer risk: a meta-analysis

Estrogens may influence gastric cancer risk, but published studies are inconclusive. We therefore carried out a meta-analysis addressing the associations of gastric cancer in women with menstrual and reproductive factors and with use of estrogen- and antiestrogen-related therapies. Searches of PubMed up to June, 2011 and review of citations yielded a total of 28 independent studies, including at least one exposure of interest. Random effects pooled estimates of relative risk (RR) and corresponding 95% CIs were calculated for eight exposures reported in at least five studies, including: age at menarche, age at menopause, years of fertility, parity, age at first birth, oral contraceptive use, hormone replacement therapy (HRT), and tamoxifen treatment. Longer years of fertility (RR = 0.74, 95% CI: 0.63-0.86) and HRT (RR = 0.77; 95% CI: 0.64-0.92) were each associated with decreased gastric cancer risk. Conversely, tamoxifen treatment was associated with increased risk (RR = 1.82; 95% CI: 1.39-2.38). The other five exposures were not significantly associated. Our analysis supports the hypothesis that longer exposure to estrogen effects of either ovarian or exogenous origin may decrease risk of gastric cancer. Additional studies are warranted to extend this finding and to identify the underlying mechanisms.

Assessment of systemic matrix metalloproteinase and their regulator response in children with Helicobacter pylori gastritis

BACKGROUND

Helicobacter pylori causes gastritis and is the most important risk factor of peptic ulcer disease and gastric cancer. In chronic adulthood H. pylori infection some matrix metalloproteinases (MMPs), which are proteolytic metalloendopeptidases regulated by tissue inhibitors of metalloproteinases (TIMPs), are upregulated. Our aim was to determine circulating levels of MMPs and their regulators TIMP-1, human neutrophil elastase (HNE) and myeloperoxidase (MPO) in childhood H. pylori infection.

DESIGN AND METHODS

Twenty-six H. pylori positive and 34 H. pylori negative children whose H. pylori status was verified by histological examination of gastric biopsies were included. Serum samples were analysed by enzyme-linked immunosorbent assay.

RESULTS

Significantly decreased serum levels of TIMP-1 were detected in H. pylori-infected children (median, 97.50 ng/mL) as compared to H. pylori-negative children (median, 118.5 ng/mL, p = 0.003). However, there were no significant differences in serum levels of MMP-2, -7, -8, -9, and their regulators HNE and MPO between H. pylori-positive and -negative children.

CONCLUSIONS

Differing from the recent findings in adulthood H. pylori infection, only circulating TIMP-1 levels were significantly different between H. pylori-positive and -negative children. Whether this reflects the first sign of a proteolytic cascade later leading to increased levels of MMPs remains to be shown.

Longitudinal analysis of serological responses of adults to Helicobacter pylori antigens

Because Helicobacter pylori persist for decades in the human stomach, the aim of this study was to examine the long-term course of H. pylori-specific serum immunoglobulin G (IgG) responses with respect to subclass and antigenic target. We studied paired serum samples obtained in 1973 and in 1994 in Vammala, Finland, from 64 healthy H. pylori-positive adults and from other healthy control subjects. H. pylori serum immunoglobulin A, IgG, and IgG subclass responses were determined by antigen-specific enzyme-linked immunosorbent assays. H. pylori-specific IgG1 and IgG4 subtype responses from 47 subjects were similar in 1973 and 1994, but not when compared with unrelated persons. H. pylori-specific IgG1:IgG4 ratios among the participants varied >1000-fold; however, 57 (89.1%) of 64 subjects had an IgG1:IgG4 ratio >1.0, consistent with a predominant IgG1 (Th1) response. Furthermore, ratios in individual hosts were stable over the 21-year period (r = 0.56; P < .001). The immune response to heat shock protein HspA was unchanged in 49 (77%) of the 64 subjects tested; of the 15 whose serostatus changed, all seroconverted and were significantly younger than those whose status did not change. These findings indicate that H. pylori-specific antibody responses are host-specific with IgG1:IgG4 ratios stable over 21 years, IgG1 responses predominating, and HspA seroconversion with aging.

Gastroenterology in developing countries: issues and advances

Developing countries shoulder a considerable burden of gastroenterological disease. Infectious diseases in particular cause enormous morbidity and mortality. Diseases which afflict both western and developing countries are often seen in more florid forms in poorer countries. Innovative techniques continuously improve and update gastroenterological practice. However, advances in diagnosis and treatment which are commonplace in the West, have yet to reach many developing countries. Clinical guidelines, based on these advances and collated in resource-rich environments, lose their relevance outside these settings. In this two-part review, we first highlight the global burden of gastroenterological disease in three major areas: diarrhoeal diseases, hepatitis B, and Helicobacter pylori. Recent progress in their management is explored, with consideration of future solutions. The second part of the review focuses on the delivery of clinical services in developing countries. Inadequate numbers of healthcare workers hamper efforts to combat gastroenterological disease. Reasons for this shortage are examined, along with possibilities for increased specialist training. Endoscopy services, the mainstay of gastroenterology in the West, are in their infancy in many developing countries. The challenges faced by those setting up a service are illustrated by the example of a Nigerian endoscopy unit. Finally, we highlight the limited scope of many clinical guidelines produced in western countries. Guidelines which take account of resource limitations in the form of "cascades" are advocated in order to make these guidelines truly global. Recognition of the different working conditions facing practitioners worldwide is an important step towards narrowing the gap between gastroenterology in rich and poor countries.

Helicobacter pylori infection and gender: a meta-analysis of population-based prevalence surveys

Although most of Helicobacter pylori-related diseases are associated with male gender, the role of gender as a risk factor for H. pylori infection is still debated. To assess the true association between H. pylori and gender, we conducted a meta-analysis of large, population-based studies where the measure of association had been adjusted at least for age and socioeconomic status, and obtained primary data from authors when information on gender associations were not presented. In 18 adult populations, the test of heterogeneity was not significant and male gender was significantly associated with H. pylori infection (summary odds ratio [OR] 1.16 [95% confidence interval (CI) 1.11, 1.22]). In 10 pediatric populations, the test of heterogeneity was of borderline significance, and the summary OR computed using a random effect model was close to 1 (summary OR 1.03 [95% CI 0.91, 1.17]). This study confirms the male predominance of H. pylori infection in adults as a global and homogeneous phenomenon; such predominance is not apparent in children. Differential antibiotic exposure or differential protective immunity between genders may explain the different results observed between children and adult studies.

Stool antigen tests for the detection of Helicobacter pylori in children

Stool specimens from 102 children (median age = 6.0 years; Helicobacter pylori in biopsy specimens, n = 43) were tested for H. pylori with the monoclonal antibody-based enzyme immunoassay HpStar. In 28 cases, the specimen was obtained with a rectal cotton swab during endoscopy. The sensitivity and specificity of the HpStar were 0.95 and 0.90, respectively, as compared with biopsy-based methods. The rectal cotton swab specimen gave accurate results in 24 of the 28 cases. Storage of specimens for 1, 3, or 7 days (n = 6) had a minor effect on the results, but one specimen's originally positive value on borderline turned negative when it was kept in room temperature. Forty-eight specimens were tested in parallel with all 3 tests used: HpStar, Premium Platinum HpSA, and the rapid test ImmunoCardSTAT! The accuracy rates of the tests were 98% for the HpSA and HpStar and 96% for the ImmunoCardSTAT! The performance of the stool antigen tests was excellent in young children.

Helicobacter pylori and specific immunoglobulin E antibodies to food allergens in children

OBJECTIVES

It has been suggested that chronic Helicobacter pylori infection may increase gastric permeability, predisposing infected children for the development of food allergies. We assessed the presence of food-specific immunoglobulin (Ig)E antibodies in H. pylori positive children and controls.

METHODS

We measured specific IgE values to six major food allergens (Pharmacia CAP-system) in a group of school-aged Caucasian (n = 36) and non-Caucasian (n = 38) children with a known H. pylori status. All children had undergone upper gastrointestinal endoscopy because of abdominal complaints.

RESULTS

Among H. pylori positive children (mean age, 8.8 years; range, 5-15 years, 25 female, 26 male), 33% (17 of 51) had an elevated food-specific IgE level to at least one of the food allergens tested. Unexpectedly, the majority of those with elevated serum food-specific IgE levels (12 of 17) were to cow's milk. Among H. pylori negative children (mean age, 9.3 years; range, 5-15 years, 13 female, 10 male), 26% (6 of 23) of the children had an elevated serum IgE level to at least one of the food allergens tested, and 9% (2 of 23) were positive to cow's milk. The difference in the number of children with an elevated serum IgE level for cow's milk in H. pylori positive and negative children was not significant. The severity of gastritis did not correlate with the presence of food-specific IgEs.

CONCLUSIONS

H. pylori infection had no effect on the manifestation of specific IgE to major food allergens in school-aged children. An IgE response to cow's milk was common among these school-aged children.

Determinants of Helicobacter pylori seroprevalence in Mexican adolescents

BACKGROUND

Helicobacter pylori infection is one of the most common human infections and is considered to play an etiologic role in several gastroduodenal diseases. In this study we determined the H. pylori seroprevalence among adolescents in Morelos, Mexico, and explored the association between seroprevalence and socioeconomic, dietary and lifestyle variables.

MATERIALS AND METHODS

A cross-sectional study was conducted in 5861 Mexican subjects aged 11-21 years. H. pylori infection was determined by an enzyme-linked immunosorbent assay previously validated in Mexico. A self-administered questionnaire was used to collect information on sociodemographic factors, housing, living conditions and food consumption. Multivariate logistic regression methods were used to obtain odds ratios and 95% confidence intervals.

RESULTS

The overall H. pylori seroprevalence was 47.6%; 40.6% in preadolescents (11-14 years), 48.6% in adolescents (15-17 years), and 59.8% in young adults (18-24 years). A positive association was found between age and H. pylori seroprevalence. Inverse associations were found for availability of drinking water, sewerage, and home appliances at the time of the subject's birth, a proxy variable of socioeconomic status. Intake of milk products and total fats was positively associated with infection.

CONCLUSIONS

This large seroprevalence study showed that H. pylori infection is frequent among adolescents in Mexico. An early acquisition of infection is indirectly suggested. Some variables denoting low socioeconomic status were inversely associated with H. pylori seroprevalence. Associations with intake of milk products and total fats suggest new hypotheses in this field of research.

Burden of Helicobacter pylori and H. pylori-related diseases in developed countries: recent developments and future implications

Helicobacter pylori colonizes the gastric mucosa. H. pylori infection is the main cause of peptic ulcer and gastric malignancy. This review gives an overview on the epidemiology of H. pylori infection and H. pylori-associated diseases in the developed world, mainly Europe, and it discusses very recent developments with regard to the prevalence and its future implications for H. pylori-associated diseases.

Transient and persistent Helicobacter pylori colonization in Native American children

Helicobacter pylori is chiefly acquired in childhood, but the exact timing of acquisition is not well understood. The main goal of this study was to assess H. pylori acquisition in a pediatric population. We studied two cohorts of Native American children: a birth cohort of 50 children and 58 older children (mean age, 53 months). We measured serum immunoglobulin G (IgG), IgM, and IgA antibodies to H. pylori whole-cell antigen and IgG antibodies to CagA. Among 44 birth cohort children monitored for more than 12 months, 24 (54.5%) had seroconversions, 7 (15.9%) were transient, and 17 (38.6%) were persistent. Among the older children, 49 (84.5%) of the 58 children were monitored for 1 year; 34 (69.4%) had H. pylori antibodies at study entry. During the next year, 7 (20.6%) children seroreverted, and of 15 initially negative children, 5 (33.3%) seroconverted. In both groups, evaluation of CagA antibodies increased the sensitivity of H. pylori detection. Serum pepsinogen I (PGI) levels in H. pylori-negative children rose significantly until age 6 months and remained constant for the next 19 months. At the time of H. pylori seroconversion, PGI peaked to levels significantly higher than in the never-seroconverted (P = 0.02) and the pre-seroconverted (P = 0.03) children, but then declined to levels paralleling those of H. pylori-negative children. Thus, H. pylori acquisition, accompanied by a transient PGI increase, was frequent in this population, especially in the second and third years of life, but often was brief.

Increase of allergen-specific immunoglobulin E antibodies from 1973 to 1994 in a Finnish population and a possible relationship to Helicobacter pylori infections

BACKGROUND

The prevalence of atopic diseases--hayfever, asthma and eczema--has increased over the past decades. The increase may be associated with decreased rates of infections such as measles, hepatitis A, tuberculosis, toxoplasmosis, and, as recently suggested, Helicobacter pylori gastritis.

OBJECTIVE

Since the increase of atopy has been mainly based on clinical studies, we wanted to study the prevalence of allergen-specific Immunoglobulin (Ig)E antibodies in two cross-sectional, adult population-based serum samples two decades apart. Since the sera had been tested for H. pylori antibodies, we also had a chance to look for a possible relationship between these two findings.

METHODS

We determined the prevalence rate of allergen-specific serum IgE antibodies against birch and timothy pollen, and cat and dog epithelium allergens by the radioallergosorbent test in a 15-54-years-old Finnish population using 326 sera collected in 1973 and 319 sera collected in 1994 from randomly selected subjects.

RESULTS

From 1973 to 1994 allergen-specific IgE prevalence rates and IgE antibody levels rose. In 1994, the prevalence rate of positive findings in 15-24-year-old population had increased from 11 to 38% (3.5-fold increase, P = 0.0001, OR 5.12, CI 95% 2.32-11.3). In older 10-year age groups similar trends did not reach significance, but the overall change was significant with all three cut-off levels of allergen-specific IgE analysed. The percentage of IgE-positive persons rose mainly in the subgroup with no H. pylori antibodies. In 1994 21% of the H. pylori-negative subjects had IgE antibodies compared with 5% of the H. pylori-positive subjects (in 1973 11% in both subgroups).

CONCLUSIONS

IgE-based evidence for an increase in IgE-mediated allergy was uncovered. The increase occurred mainly in the subgroup with no antibodies to H. pylori, which support the hypothesis that H. pylori could be one of the microbes counteracting atopy.

Epidemiology of Helicobacter pylori infection in children: a serologic study of the Kyushu region in Japan

BACKGROUND

The prevalence of Helicobacter pylori infection in children varies as a function of socioeconomic development, with low rates in developed countries and high rates in developing countries. The prevalence of H. pylori infection in Japanese children is unknown.

METHODS

The present study examined the effect of living conditions on the prevalence of H. pylori infection in children. We determined the prevalence of H. pylori infection in healthy children of the Kyushu region in Japan and compared it with the prevalence in institutionalized children with severe neurologic illness. Serum concentrations of anti-H. pylori IgG antibody were measured by an enzyme-linked immunosorbent assay in 336 healthy children and 56 patients with severe neurologic impairment. An antibody concentration > 50 units/mL was taken as evidence of infection.

RESULTS

The prevalence of H. pylori seropositivity in healthy children increased with age (P < 0.0001) and was 29% in children 15-19 years of age. This value is slightly higher than prevalences reported in developed countries (5-15%), but is lower than in developing countries (30-60%). Seropositivity did not vary with respect to gender, water supply or location of housing. Helicobacter pylori seropositivity was more prevalent among institutionalized children aged 5-19 years than their healthy counterparts (P < 0.005).

CONCLUSIONS

The intermediate prevalence of H. pylori seropositivity in healthy children between that measured in developed and developing countries is consistent with the socioeconomic 'westernization' of Japan.

Recent developments in the epidemiology of Helicobacter pylori

Prevalence determinations have been performed around the world, and regardless of how exotic a location, H. pylori is found in a substantial proportion of the population. H. pylori remains among the most universal of infections. Understanding of some features of infection has changed. Infection can be gained and lost at rates higher than previously realized. Oral-oral and oral-fecal transmission account for most, if not nearly all, cases of infection. H. pylori infection has declined rapidly in developed countries, which probably has contributed to declines in duodenal ulcer disease and gastric cancer. The full health implications of the potential elimination of infection are unknown.

Parietal cell antibodies and Helicobacter pylori in children

BACKGROUND

Gastric autoantibodies are common in Helicobacter pylori-infected adults, and the presence of these antibodies is associated with atrophic gastritis. The role of H. pylori in the autoimmune type of atrophic gastritis is unresolved, and it is not known at what stage the autoantibodies appear in serum during H. pylori infection. Therefore, we screened children with and without H. pylori infection for gastric parietal cell antibodies.

METHODS

Seventy-one children with H. pylori infection verified by examination of gastric biopsy specimens (mean age, 9.4 years), 8 children with positive serology but negative histology for H. pylori (mean age, 11.6 years), and 130 children with negative serology for H. pylori (mean age, 7.7 years) were screened for the presence of gastric parietal cell antibodies in serum by indirect immunofluorescence. In addition, 61 children with celiac disease (mean age, 7.1 years) were screened for gastric parietal cell antibodies and H. pylori antibodies.

RESULTS

None of the children with H. pylori infection had gastric parietal cell antibodies in serum. Only three positive parietal cell antibody reactions were found: a 14-year-old boy with positive serology for H. pylori but no other signs of infection (titer 5000), a 14-year-old girl with tuberculosis (titer 1250, seronegative for H. pylori) and a 10-year-old girl with insulin-dependent diabetes mellitus (titer 6250, seronegative for H. pylori).

CONCLUSIONS

Although gastric autoantibodies are often found in adults with chronic H. pylori gastritis, it seems that H. pylori-infected children are not positive for gastric parietal cell antibodies. It remains to be studied in which H. pylori infections and at what stages gastric autoantibodies appear.

Helicobacter pylori infection in pediatric patients

Helicobacter pylori is a gram-negative, spiral organism that colonizes the gastric mucosa and causes primary antral gastritis and peptic ulcer disease. Recent studies indicate that H. pylori infection acquired in childhood may cause gastric cancer in later life. H. pylori is present in both asymptomatic and symptomatic children as determined by various epidemiologic studies. The natural history of H. pylori infection is still an enigma. Its association with varied symptoms in children is considered controversial because it is frequently associated with nonulcerative gastritis in this age group. This article focuses on some of the newer developments addressing the epidemiology, transmission, pathophysiology, clinical presentation, and treatment of H. pylori infection in the pediatric population.