Parietal cell antibodies and Helicobacter pylori in children

Type 1 diabetes mellitus and risk of cancer: a meta-analysis of observational studies

Objective

Previous observational studies have focused on the link between type 2 diabetes and the risk of cancer. However, the association between type 1 diabetes and the risk of cancer has not been well addressed. This study aimed to investigate the association between type 1 diabetes and the risk of cancer by using a meta-analysis of observational studies.

Methods

We searched PubMed and EMBASE for observational studies that examined the association between type 1 diabetes and cancer in April 2017. We calculated the pooled odds ratios (ORs) or relative risks (RRs) with confidence intervals (CIs) from individual studies based on a random-effects model meta-analysis.

Results

We included a total of 15 observational studies with two case-control studies and 13 cohort studies involving 31 893 cancer patients among a total of 1 915 179 participants in the final analysis. In the random-effects meta-analysis of all studies, patients with type 1 diabetes had an increased risk of cancer (OR or RR, 1.29; 95% CI, 1.09-1.52; n = 15; I2 = 95.2%). In the subgroup meta-analysis by type of cancer, type 1 diabetes significantly increased the risk of cancers of stomach, lung, pancreas, liver, ovary and kidney, whereas it significantly decreased the risk of breast cancer (OR or RR, 0.91; 95% CI, 0.86-0.95; n = 9; I2 = 0%).

Conclusion

This meta-analysis suggests that type 1 diabetes is associated with the increased risk of several types of cancer and the decreased risk of breast cancer. However, the plausible mechanisms for the decreased risk of breast cancer remain unclear. Further prospective studies with proper adjustment for possible confounding factors are warranted.

Revisiting autoimmune gastritis in children and adolescents with type 1 diabetes

OBJECTIVE

Assess the frequency of anti-H⁺ /K⁺ adenosine triphosphatase (ATPase) autoantibodies (AAB) and symptoms of autoimmune gastritis in children and adolescents with type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

Anti-H⁺ /K⁺ ATPase AAB were measured in 402 children and adolescents (210 boys and 192 girls, 11.1 ± 4.5 years) treated for T1D (screened positive for β-cell AAB), along with search of symptoms of anemia (hemoglobin, serum iron, and ferritin levels) and gastric pain. The AAB specific for thyroperoxydase, thyroglobulin, and transglutaminase were also measured.

RESULTS

Anti-H⁺ /K⁺ ATPase AAB were present in 6.5% of children. Their frequency increased with age: 4% at 10 years, 10% at 15 years, and 20% at 20 years. Iron deficiency (45% vs 3.8%), iron deficiency anemia (36% vs 3.8%), antithyroid AAB (24% vs 9.7%), and family history of Graves' disease (25% vs 5.6%) were more frequent in patients with anti-H⁺ /K⁺ ATPase AAB. Two patients, a 13-year-old girl and a 11-year-old boy, experienced symptoms (iron deficiency anemia and epigastric pain) which led to diagnosis of autoimmune gastritis confirmed upon fibroscopy. Both showed high levels of anti-H⁺ /K⁺ ATPase AAB and atrophic gastritis.

CONCLUSIONS

Autoimmune gastritis presents an age-dependent frequency in children and adolescents with T1D but is rarely symptomatic. Screening for anti-H⁺ /K⁺ ATPase AAB should thus target patients with iron deficiency, anemia, epigastralgia, autoimmune thyroiditis, or age over 15 years.

Gastric parietal cell antibodies, Helicobacter pylori infection, and chronic atrophic gastritis: evidence from a large population-based study in Germany

BACKGROUND

Striking similarities between autoimmune gastritis and Helicobacter Pylori (H. pylori)-associated gastritis have suggested a potential link between these two pathologic conditions in the progression of chronic atrophic gastritis (CAG); however, evidence has remained conflicting.

METHODS

Serum pepsinogen I and II, and antibodies against H. pylori in general, the cytotoxin-associated gene A protein (CagA) and parietal cells were measured by ELISA in 9,684 subjects aged 50 to 74 years. Antigastric parietal cell antibody (APCA) prevalence was examined in the overall population and according to sex, age, and H. pylori serostatus. The association between APCA prevalence and CAG was assessed by logistic regression, overall and according to H. pylori status, controlling for potential confounding factors.

RESULTS

Overall APCA prevalence was 19.5%. APCA prevalence was strongly associated with CAG, and the association was increasing with increasing severity of CAG. Furthermore, the association between APCA and CAG was even stronger among H. pylori-negative subjects [odds ratio (OR) = 11.3; 95% confidence interval (CI): 7.5-17.1)] than among H. pylori-positive subjects (OR = 2.6; 95% CI: 2.1-3.3).

CONCLUSIONS

APCA may play a role on the development of gastric atrophy, irrespective of H. pylori infection.

IMPACT

Assessment of APCA might be a useful complement to established markers (such as pepsinogens and H. pylori antibodies) in screening for CAG.

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.

Does gastric atrophy exist in children?

Several clinical reports confirmed that gastric atrophy is a pathology not only limited to adult patients. In pediatrics, it is most often described in association with a H pylori infection but this bacteria does not seem to be the only etiological factor of this preneoplastic state in children. The frequency of gastric atrophy and intestinal metaplasia in children are unknown because they are not systematically sought during upper gastrointestinal endoscopy. The lack of specific histological classification of children’s gastropathies makes their diagnosis difficult for pathologists. Based on our knowledge to date, we think that it is necessary to describe, in detail, the natural course of this lesion during childhood. A close and prolonged clinical and endoscopic follow-up is important for children with gastric atrophy.

Is GastroPanel serum assay useful in the diagnosis of Helicobacter pylori infection and associated gastritis in children?

GastroPanel (Biohit, Helsinki, Finland) is a serum test kit that measures Helicobacter pylori antibodies (HPABs) and pepsinogens I and II and gastrin 17, which reflect the degree of atrophic gastritis. We assessed whether GastroPanel can replace endoscopic biopsies in the diagnostics of H. pylori in children and whether the H. pylori-infected children show markers for atrophic gastritis. Eighty children (median age, 6.8 years; range, 0.6-18.7 years) underwent gastroscopy for H. pylori-related abdominal complaints (n = 40), surveillance after surgery for gastrointestinal tract malformations (n = 20), gastroesophageal reflux (GER) (n = 10), and miscellaneous diseases (n = 10). Gastric biopsies and a serum sample were obtained from all 80 children. HPAB levels of 38 and 15 IU were tested as cutoff values for H. pylori gastritis. The biopsies showed H. pylori-positive gastritis in 30 children, 9 had gastritis not associated with H. pylori, and 41 had normal biopsies. Atrophic gastritis was not found. The sensitivity and specificity of HPAB for H. pylori were 47% and 98% (cutoff, 38 IU), and 73% and 85% (cutoff, 15 IU), respectively. The assays of pepsinogens and gastrin did not improve sensitivity. None of the markers of pepsinogen (PG) I, PGII, and gastrin 17 (G17) indicated atrophic gastritis. GastroPanel is too insensitive for H. pylori screening and does not replace endoscopy. Markers indicative of atrophic gastritis were negative in all children with H. pylori gastritis.

Contribution of epidemiological studies to gastritis immunology

Chronic gastritis, or chronic inflammation in gastric antral and/or corpus mucosa, is a common pathological condition affecting over half the general population. Progression of chronic gastritis from Helicobacter pylori infection to severe gastric mucosal atrophy usually takes decades and varies considerably from person to person. Therefore, studies of clinically selected material cannot provide a complete picture of natural evolution of the disease or its wide variability. An overview of immunological and morphological aspects of chronic gastritis in an epidemiological context, based on data from the literature and the author's studies, reveal dynamic interaction between H. pylori infection and host response to the organism's antigens, and to gastric autoantigens including gastric H+K+ ATPase. Further population and followup studies of antral and corpus gastritis at different stages of evolution are needed, in combination with new methods, to elucidate further the roles of infection, and gastric-antrum- and corpus-mucosa-related autoimmune responses, in the pathogenesis of chronic gastritis.

Organ-specific autoantibodies in children with Helicobacter pylori infection

BACKGROUND

We compared the prevalence of organ-specific autoantibodies in a group of Helicobacter pylori infected children and a group of uninfected children and investigated the relationship between the presence of relevant autoantibodies and the status of the target organs.

PATIENTS AND METHODS

One hundred and twenty-four children with dyspepsia (54 boys, 70 girls; mean age 10.5 years; range 4-19) underwent gastroscopy: 56 had H. pylori infection (31 girls, 25 boys), while 68 (37 girls and 31 boys), were H. pylori-negative. All sera were tested for the presence of: parietal cell autoantibodies (PCA), intrinsic factor autoantibodies (IFA), microsomial autoantibodies, thyroglobulin autoantibodies, islet cell autoantibodies, glutamic acid decarboxylase autoantibodies, adrenal cortex autoantibodies, steroid-producing cell autoantibodies; gastrin, pepsinogen A, pepsinogen C and anti-H. pylori antibodies. The histological features and the ureA and cagA genes were also considered.

RESULTS

The frequency of organ-specific autoantibodies was higher in patients with H. pylori infection than in uninfected patients (chi2-test p < .0001). Specifically gastric autoantibodies were significantly higher: seven of the 56 H. pylori-positive children were PCA-positive and one was IFA-positive (chi2-test p = .0004). The presence of autoantibodies was not associated with any clinical or biohumoral signs of disease.

CONCLUSIONS

Our study detected a relationship between H. pylori infection in childhood and the presence of organ-specific autoantibodies unassociated with any clinical or biohumoral signs of disease. Helicobacter pylori infection in childhood could trigger the onset of clinical autoimmune gastritis, and/or other clinical autoimmune diseases.

Helicobacter pylori infection in Finland

Helicobacter pylori causes chronic gastritis worldwide and it is the most important single factor in peptic ulcer disease. Up to half of H. pylori infected individuals develop atrophic gastritis over years and decades. H. pylori infection has also been classified as a class I carcinogen in human gastric cancer. Most infections are obtained in childhood, in Finland mainly before the age of 7 years but the exact transmission routes are not known. The infection shows an age-dependent pattern, the infection being rare among children but gradually becoming more prevalent among older age groups. As new infections are few in adults and the infection only rarely disappears without effective anti-microbial therapy, the occurrence of the infection in the old actually reflects the prevalence of the infection in their childhood. In developed countries, such as Finland, a rapid decline of H. pylori prevalence rate has been demonstrated. In order to speed up this natural decline of the infection, a unique population based 'screen and treat' project was started in Vammala, a semiurban south-western community in Finland. In this survey, young inhabitants were offered diagnosis and treatment for H. pylori.

Dental caries is common in Finnish children infected with Helicobacter pylori

Childhood factors such as low socioeconomic status are risk factors for Helicobacter pylori infection and Streptococcus mutans-related dental caries. We examined whether H. pylori infection and dental caries are present today in the same group of children examined previously. We reviewed the public dental health service files of 21 H. pylori-positive children (upper gastrointestinal endoscopy at a median age of 13.5 y) and 27 H. pylori-negative children (endoscopy at a median age of 12.5 y) examined during 1995-98 at the Helsinki University Central Hospital, Finland. All H. pylori-positive children had experienced dental caries in their primary or permanent teeth or in both whereas among H. pylori-negative children the respective proportion was 70% (p < 0.01). At the age of 7 y, 18% (3/17) of the H. pylori-positive children had experienced caries in permanent teeth as compared to 0% among H. pylori-negative children (0/24; p < 0.05). At the age of 12 y, H. pylori-positive children had more decayed, missing or filled permanent teeth than H. pylori-negative children (80% vs. 38%; p < 0.05). Although a causal relationship between H. pylori and dental caries is unlikely, it is possible that H. pylori-infected children have an increased risk of other health problems, such as dental caries, for which proper treatment is needed.

Prevalence and specificity of antigastric autoantibodies in adolescents infected with Helicobacter pylori

OBJECTIVES

Antigastric autoantibodies (AGA) can be detected in as many as 50% of adults infected with Helicobacter pylori. We investigated H pylori -associated antigastric autoimmunity in children and adolescents.

STUDY DESIGN

Patients with dyspepsia (n = 78; mean age 10.9 years, range 2-21 years, SE 0.46 years) underwent gastroscopy. H pylori infection was determined by serologic and histologic features and breath tests. AGA were detected by immunohistochemistry and were characterized by immunoprecipitation with the gastric hydrogen ion, potassium ion, adenosine triphosphatase (H(+),K(+)-ATPase). In absorption assays, antibodies against H pylori were removed to determine the role of molecular mimicry.

RESULTS

AGA were detected in 9 (18%) of the 51 infected patients and in 1 (4 %) of the 27 noninfected patients (P =.08; nonsignificant) and could not be absorbed to H pylori. Children with AGA were significantly older (P =.01). AGA in H pylori gastritis reacted against the gastric H(+),K(+)-ATPase in 3 (33%) of the 9 patients.

CONCLUSIONS

The age of the patient or the duration of gastritis seem to be relevant factors for the formation of antigastric autoimmunity. The gastric H(+),K(+)-ATPase represents an autoantigen as early as childhood. No evidence for a role of molecular mimicry between H pylori and the host at this young age could be found.

The role of Helicobacter pylori in paediatrics

Helicobacter pylori is a bacterium that colonizes the human stomach, especially during childhood. Although it has been studied intensively during the past decade, many controversies still exist on many important issues, including the clinical relevance of virulence factors, indications for treatment, recommended procedures for diagnosis and the typical symptom profile, among others. The lack of double-blind, placebo-controlled studies in children illustrates the paucity of hard scientific data, and is the major reason for differences in opinion. Therefore, the present review of literature published during the past 2 years raises many questions.