Extragastric manifestations of Helicobacter pylori infection: other Helicobacters

Effect of Helicobacter pylori Infection on Macromineral and Trace Element Status-Systematic Review and Meta-Analysis

OBJECTIVES

To explore the effect of Helicobacter pylori (Hp ) infection on zinc, copper, calcium, magnesium, phosphorus, and iodine status in the pediatric population.

METHODS

A protocol was registered on PROSPERO. A literature search was conducted on Embase, PubMed MEDLINE, and Web of Science, from inception to September 2020, including all studies in English, Spanish, and Portuguese languages. Reference lists were manually searched. Primary studies describing at least one micronutrient status in Hp -positive and Hp -negative or control children were included. PRISMA recommendations were applied. Pooled mean differences (MDs) and 95% confidence intervals were estimated using a random-effects model. A total of 1011 citations were screened. Six cross- sectional studies were included. No publications regarding phosphorus and iodine were identified.

RESULTS

Included studies in meta-analyses comprised an overall age range of 4-18 years, with Hp positivity ranging between 29.5% and 72.3%. These meta-analyses demonstrated a lack of evidence of an association between Hp -positive and Hp -negative or control children regarding serum zinc (vs Hp -negative: MD -1.36 µg/dL; vs control: MD 326.22 µg/dL), copper (MD -0.83 µg/dL), and calcium (MD 0.09 mg/dL) status. Considerable heterogeneity was recognized, except for calcium analysis (I 2 = 0%). Meta-analysis for magnesium was not performed. Five studies presented a low risk of bias.

CONCLUSIONS

The study demonstrated a lack of evidence of an effect of Hp infection on serum zinc, copper, and calcium status. Studies concerning magnesium, phosphorus, and iodine status are warranted. Furthermore, larger and well-controlled studies are recommended.

Relationship Between Helicobacter pylori Infection and Arteriosclerosis

It is reported that Helicobacter pylori (H. pylori) infection may be linked to non-digestive tract diseases, such as arteriosclerosis including dyslipidemia, diabetes, obesity, hypertension, and cardiovascular disease. Therefore, we reviewed recent studies available in PubMed dealing with the mechanisms of arteriosclerosis due to H. pylori infection and the effects of H. pylori eradication. Conventional studies suggested that H. pylori infection may increase the risk of arteriosclerosis. A large interventional study is required to clarify the causal relationships and the effects of bacterial eradication.

Helicobacter pylori Related Diseases and Osteoporotic Fractures (Narrative Review)

Osteoporosis (OP) and osteoporotic fractures (OFs) are common multifactorial and heterogenic disorders of increasing incidence. Helicobacter pylori (H.p.) colonizes the stomach approximately in half of the world's population, causes gastroduodenal diseases and is prevalent in numerous extra-digestive diseases known to be associated with OP/OF. The studies regarding relationship between H.p. infection (HPI) and OP/OFs are inconsistent. The current review summarizes the relevant literature on the potential role of HPI in OP, falls and OFs and highlights the reasons for controversies in the publications. In the first section, after a brief overview of HPI biological features, we analyze the studies evaluating the association of HPI and bone status. The second part includes data on the prevalence of OP/OFs in HPI-induced gastroduodenal diseases (peptic ulcer, chronic/atrophic gastritis and cancer) and the effects of acid-suppressive drugs. In the next section, we discuss the possible contribution of HPI-associated extra-digestive diseases and medications to OP/OF, focusing on conditions affecting both bone homeostasis and predisposing to falls. In the last section, we describe clinical implications of accumulated data on HPI as a co-factor of OP/OF and present a feasible five-step algorithm for OP/OF risk assessment and management in regard to HPI, emphasizing the importance of an integrative (but differentiated) holistic approach. Increased awareness about the consequences of HPI linked to OP/OF can aid early detection and management. Further research on the HPI-OP/OF relationship is needed to close current knowledge gaps and improve clinical management of both OP/OF and HPI-related disorders.

Helicobacter pylori participates in the pathogenesis of IgA nephropathy

Increasing evidences have shown that Helicobacter pylori (Hp) is a pathogen closely related to extra-gastric disorders. Our previous in vitro studies had demonstrated that Hp infection, at least via cytotoxin-associated gene A protein (CagA), might play an important role in the pathogenesis of IgA nephropathy (IgAN) by stimulating proliferation and ectopic synthesis of aberrantly glycosylated IgA1 of B cells. However, the relevant clinical evidence of IgAN resulted from Hp infection remain to be elucidated. This study aimed to investigate the risk incidence of IgAN caused by Hp infection. 22 primary IgAN, 20 non-IgA nephropathy (n-IgAN), and 30 healthy controls were included in this study. We found that the rate of IgG anti-Hp seropositivity was significantly improved in IgAN, but the current Hp infection was similar in all groups. The production and underglycosylation of IgA1 tended to increase in IgAN patients with IgG anti-Hp seropositivity. A tendency toward increased the risk of clinical prognosis was seen in IgAN with Hp infection. Hp antigen and CagA were only deposited in renal tubules, and enhanced antigen deposition in response to Hp was observed in IgAN. Our study suggested that Hp infection might have a pathogenic role in IgAN through giving rise to strongly mucosal immune response, and based on damage of renal tubular.

Does Helicobacter pylori play a role in the pathogenesis of non-cystic fibrosis bronchiectasis?

BACKGROUND

The aim of this study was to investigate whether Helicobacter pylori plays a role in the pathogenesis and severity of non-cystic fibrosis bronchiectasis, and its relationship with gastroesophageal reflux (GER).

METHODS

Forty-one patients and 16 controls between 5 and 18 years of age were enrolled. H. pylori was investigated on polymerase chain reaction and culture in gastric juice (GJ) and bronchoalveolar lavage fluid (BALF). Urea breath test (UBT) was also used for defining H. pylori infection. GER was detected on 24 h pH monitoring or scintigraphy. Computed tomography (CT) scoring was used to quantify the severity and extent of bronchiectasis.

RESULTS

Nine patients (22%) in the bronchiectasis group (BG) and three patients (18.8%) in the control group (CG) had H. pylori-positive BALF. Sixteen BG patients (39%) and seven CG patients (43.8%) had H. pylori-positive GJ. UBT was positive in 11 BG patients (26.8%) and in three CG patients (18.8%). H. pylori positivity in BALF, GJ and UBT was not significantly different between the two groups (P > 0.05). Six patients with GER and five patients without GER in BG had H. pylori-positive BALF and GJ (P = 0.827). No association was found between BALF H. pylori positivity and forced expiratory volume in 1 s (FEV1 ) in BG. CT score was significantly higher in BG patients with H. pylori-positive compared with H. pylori-negative BALF (P < 0.05).

CONCLUSIONS

Helicobacter pylori is not associated with the pathogenesis of bronchiectasis but it may be responsible for the severity of the disease.

Is Helicobacter pylori infection associated with glycemic control in diabetics?

AIM

To investigate whether Helicobacter pylori (H. pylori) infection is associated with glycemic control and whether hyperglycemia is modified by eradication therapy.

METHODS

The databases of PubMed, Cochrane Library, Chinese BioMedicine Web Base and Chinese Science and Technology Journals were searched from inception to June 2014. Studies examining the association between H. pylori infection and glycemic control and/or the effect of eradication treatment on glycemic control in diabetic humans were eligible for inclusion. Meta-analyses were conducted using the Review Manager software version 5.2. The outcome measures are presented as weighed mean differences (WMDs) with 95% confidence intervals (CIs). Statistical heterogeneity was assessed by the Cochran Q test and the I(2) statistic.

RESULTS

A total of 21 relevant publications were identified. A meta-analysis of 11 studies with 513 patients with diabetes mellitus (DM) showed significantly lower glycosylated hemoglobin (HbA1c) levels in the H. pylori-negative than H. pylori-positive DM participants (WMD = 0.43, 95%CI: 0.07-0.79; P = 0.02). In children and adolescents with type 1 DM (T1DM), there was a positive association between H. pylori infection and HbA1c level (WMD = 0.35, 95%CI: 0.05-0.64; P = 0.02), but there was no difference in those with type 2 DM (T2DM, WMD = 0.51, 95%CI: -0.63-1.65; P = 0.38). A meta-analysis of six studies with 325 T2DM participants showed a significant difference in the fasting plasma glucose levels between H. pylori-positive and H. pylori-negative participants (WMD = 1.20, 95%CI: 0.17-2.23; P = 0.02). Eradication of H. pylori did not improve glycemic control in the T2DM participants in a three-month follow-up period (HbA1c decrease: WMD = -0.03, 95%CI = -0.14-0.08; P = 0.57; fasting plasma glucose decrease: WMD = -0.06, 95%CI: -0.36-0.23; P = 0.68). Glycemic control was significantly better in T1DM participants who were not reinfected than in those who were reinfected (HbA1c: WMD = 0.72, 95%CI: 0.32-1.13: P = 0.00).

CONCLUSION

H. pylori infection is associated with poorer glycemic control in T1DM patients, but eradication may not improve glycemic control in DM in a short-term follow-up period.

Gastric biopsies: the gap between evidence-based medicine and daily practice in the management of gastric Helicobacter pylori infection

BACKGROUND

Many consider histology to be the gold standard for Helicobacter pylori detection. Because the number and distribution of H pylori organisms vary, particularly in patients taking proton pump inhibitors (PPIs), the American Gastroenterological Association recommends discontinuing PPIs two weeks before endoscopy, and taking biopsies from both the body and antrum.

OBJECTIVE

To assess the influence of clinical practice on the histopathological detection of H pylori infection.

METHODS

Electronic patient records were evaluated for the sites of gastric sampling and PPI use at endoscopy. One hundred fifty cases with biopsies taken from both antrum and body were randomly selected for pathological re-review with special stains. The gastric regions sampled, H pylori distribution and influence of clinical factors on pathological interpretation were assessed.

RESULTS

Between 2005 and 2010, 10,268 biopsies were taken to detect H pylori. Only one region was sampled in 60% of patients (antrum 47%, body 13%). Re-review of biopsies taken from both antrum and body indicated that the correct regions were sampled in only 85 (57%) patients. Of these, 54 were H pylori positive and 96 were H pylori negative. H pylori was present in the antrum in only 15% of the patients and body only in 21%. Of 96 H pylori-negative patients, two were reinterpreted as positive. Forty-seven per cent of patients were taking PPIs at endoscopy, contributing to both false-negative and false-positive diagnoses.

CONCLUSION

Despite national and international guidelines for managing H pylori infection, the American Gastroenterological Association guidelines are infrequently adhered to, with PPIs frequently contributing to false diagnosis; sampling one region only increases the likelihood of missing active infection by at least 15%.

Clinical effects of Helicobacter pylori outside the stomach

The discovery of Helicobacter pylori infection in the stomach could be considered as one of the most important events of modern gastroenterology. Understanding of the natural history of many disorders of the upper gastrointestinal tract, including chronic gastritis, peptic ulcer disease, gastric cancer and MALT lymphoma, was altered by this discovery. Interestingly, epidemiological studies have also revealed a correlation between H. pylori infection and some diseases localized outside the stomach, especially those characterized by persistent and low-grade systemic inflammation. Of note, H. pylori has an important role in iron deficiency anaemia, idiopathic thrombocytopenic purpura and vitamin B12 deficiency. Moreover, the association of this bacterial pathogen with many other diseases, including hepatobiliary, pancreatic, cardiovascular and neurodegenerative disorders is currently under investigation. In this Review, we summarize the results of the most important studies performed to date surrounding the association of H. pylori infection with extragastric diseases, as well as the strength of the evidence. We also provide information concerning bacterial-host interactions and the mechanisms implicated in the pathogenesis of each of these extragastric diseases.

Occurrence of ε-proteobacterial species in rabbits (Oryctolagus cuniculus) reared in intensive and rural farms

In order to investigate the occurrence of Campylobacter, Helicobacter and Arcobacter species in caecal contents of rabbits reared in intensive and rural farms, a total of 87 samples from animals belonging to 29 farms were analysed by both cultural and PCR analyses. PCR analysis directly from faecal samples detected 100% positive samples for Campylobacter genus, 3.4% for Helicobacter genus and none for Arcobacter genus. 83 out of 87 animals (95.4%) and all the 29 farms were positive for Campylobacter cuniculorum as also determined by cultural examination. Campylobacter coli and Campylobacter jejuni were isolated only from three animals reared in two rural farms. No Helicobacter and Arcobacter species were isolated. To evaluate a possible genetic variability, one strain of C. cuniculorum from each farm was analysed by Pulsed Field Gel Electrophoresis (PFGE) and Amplified Fragment Length Polymorphism (AFLP). Genotyping revealed that C. cuniculorum population is heterogeneous among the different sources and no dominant clone has spread in the investigated farms. This survey highlighted a high presence of C. cuniculorum with a high rate of intestinal colonization, low presence of C. jejuni-coli, Helicobacter spp. and any Arcobacter spp. in farmed rabbits.

Micronutrients (Other than iron) and Helicobacter pylori infection: a systematic review

BACKGROUND

Many micronutrients depend on a healthy stomach for absorption. Helicobacter pylori chronic gastritis may alter gastric physiology affecting homeostasis of vitamins and minerals.

OBJECTIVES

Systematic review to assess whether H. pylori infection is associated with reduced micronutrient levels (other than iron) in the plasma or gastric juice and whether low micronutrient levels are modified by eradication treatment.

METHOD

Medline was searched for relevant publications from inception to June 2010. Studies describing micronutrient levels in H. pylori-infected and not-infected adults and/or the effect of eradication treatment on micronutrient levels were included.

FINDINGS

Fifty-two publications were selected: 46 investigated the association between H. pylori infection and reduced micronutrient levels and 14 the effect of eradication treatment on micronutrient levels. Sixty-four studies investigated vitamins (23 ascorbic acid, four ß-carotene, 21 cobalamin, 11 folate, and five α-tocopherol) and 10 addressed minerals (one calcium, one copper, one magnesium, one phosphorus, three selenium, and three zinc). Pooled standardized mean differences in micronutrient levels showed positive associations with H. pylori infection for ascorbic acid (gastric juice, -1.087) and cobalamin (-0.744), and a positive effect of eradication treatment, which increased ascorbic acid in the gastric juice (-1.408) and serum cobalamin (-1.910). No significant association between infection and low folate levels was observed. Meta-analyses for other micronutrients were not performed owing to insufficient data.

CONCLUSIONS

Meta-analyses indicate that H. pylori infection is associated with reduced levels of ascorbic acid and cobalamin, supported by the positive effect of eradication treatment. For other micronutrients, further studies are needed.

Interleukin-8 is the single most up-regulated gene in whole genome profiling of H. pylori exposed gastric epithelial cells

BACKGROUND

The association between Helicobacter pylori infection and upper gastrointestinal disease is well established. However, only a small fraction of H. pylori carriers develop disease, and there are great geographical differences in disease penetrance. The explanation to this enigma lies in the interaction between the bacterium and the host. H. pylori Outer Membrane Phospholipase A (OMPLA) has been suggested to play a role in the virulence of this bacterium. The aim of this study was to profile the most significant cellular pathways and biological processes affected in gastric epithelial cells during 24 h of H. pylori exposure, and to study the inflammatory response to OMPLA⁺ and OMPLA⁻ H. pylori variants.

RESULTS

Interleukin-8 was the most significantly up-regulated gene and appears to play a paramount role in the epithelial cell response to H. pylori infection and in the pathological processes leading to gastric disease. MAPK and NF-kappaB cellular pathways were powerfully activated, but did not seem to explain the impressive IL-8 response. There was marked up-regulation of TP53BP2, whose corresponding protein ASPP2 may interact with H. pylori CagA and cause marked p53 suppression of apoptosis. Other regulators of apoptosis also showed abberant regulation. We also identified up-regulation of several oncogenes and down-regulation of tumor suppressor genes as early as during the first 24 h of infection. H. pylori OMPLA phase variation did not seem to influence the inflammatory epithelial cell gene response in this experiment.

CONCLUSION

In whole genome analysis of the epithelial response to H. pylori exposure, IL-8 demonstrated the most marked up-regulation, and was involved in many of the most important cellular response processes to the infection. There was dysregulation of apoptosis, tumor suppressor genes and oncogenes as early as in the first 24 h of H. pylori infection, which may represent early signs of gastric tumorigenesis. OMPLA⁺/⁻ did not affect the acute inflammatory response to H. pylori.

Association between Helicobacter pylori Seropositivity and the Coronary Artery Calcium Score in a Screening Population

BACKGROUND/AIMS

Helicobacter pylori causes numerous extragastric manifestations, including coronary heart disease. The coronary artery calcification (CAC) score, measured using computed tomography (CT) has been used as a screening test for coronary atherosclerosis. This study investigated the association between H. pylori seropositivity and CAC scores in a screening population.

METHODS

Patients who underwent a health checkup between October 2003 and July 2007 and who did not have a history of ischemic heart disease were enrolled in the study. Subjects were screened with a multidetector CT scan to determine the CAC score and for anti-H. pylori antibody immunoglobulin G; traditional risks for coronary heart disease were evaluated using a structured questionnaire, anthropometric measurements, and laboratory tests.

RESULTS

Of the 2,029 subjects enrolled (1,295 males), 1,214 (59.8%) subjects were H. pylori positive and 815 were H. pylori negative. There were no significant differences in the baseline characteristics of the seropositive and seronegative patients. When the CAC presence or absence scores were considered, multivariate analysis revealed that H. pylori seropositivity was statistically associated with the presence of CAC and that this association was stronger in the mild CAC score category.

CONCLUSIONS

H. pylori seropositive patients are at a higher risk for coronary atherosclerosis regardless of traditional cardiovascular risk factors. This association is particularly applicable for early coronary atherosclerosis.

Association between Helicobacter pylori Seropositivity and the Coronary Artery Calcium Score in a Screening Population

BACKGROUND/AIMS

Helicobacter pylori causes numerous extragastric manifestations, including coronary heart disease. The coronary artery calcification (CAC) score, measured using computed tomography (CT) has been used as a screening test for coronary atherosclerosis. This study investigated the association between H. pylori seropositivity and CAC scores in a screening population.

METHODS

Patients who underwent a health checkup between October 2003 and July 2007 and who did not have a history of ischemic heart disease were enrolled in the study. Subjects were screened with a multidetector CT scan to determine the CAC score and for anti-H. pylori antibody immunoglobulin G; traditional risks for coronary heart disease were evaluated using a structured questionnaire, anthropometric measurements, and laboratory tests.

RESULTS

Of the 2,029 subjects enrolled (1,295 males), 1,214 (59.8%) subjects were H. pylori positive and 815 were H. pylori negative. There were no significant differences in the baseline characteristics of the seropositive and seronegative patients. When the CAC presence or absence scores were considered, multivariate analysis revealed that H. pylori seropositivity was statistically associated with the presence of CAC and that this association was stronger in the mild CAC score category.

CONCLUSIONS

H. pylori seropositive patients are at a higher risk for coronary atherosclerosis regardless of traditional cardiovascular risk factors. This association is particularly applicable for early coronary atherosclerosis.

Coronary atherosclerotic burden in patients with infection by CagA-positive strains of Helicobacter pylori

OBJECTIVES

Cytotoxic associated gene-A (CagA)-positive strains of Helicobacter pylori emerged as a possible atherosclerotic stimulus. Nevertheless, whether CagA-positivity is associated with more extensive or severe atherosclerotic coronary burden has never been studied.

METHODS

Forty consecutive patients with coronary artery disease (CAD) and twenty consecutive patients with normal coronary arteries undergoing coronary angiography were enrolled. All patients underwent evaluation of classical atherogenic risk factors and assessment of anti-urease B and anti-CagA antibodies titer. Either the severity of coronary stenosis (stenosis score) or the extent of coronary atherosclerosis (extent score) was evaluated in CAD patients.

RESULTS

The anti-CagA antibody titer was significantly higher in patients with CAD as compared with normal coronary arteries patients [85 (10-108.75) vs. 47.3 (17-64) RU/ml, P=0.02], whereas there were no differences in anti-urease B titer between the two groups. A significant correlation was found between anti-CagA antibody titer and extent score (R=0.35, P=0.03), whereas stenosis score was similar (R=0.25, P=0.11). On the contrary, no significant correlation was found between anti-urease B antibody titer and either extent or stenosis score. Moreover, CagA-positive patients had a more extensive CAD (P=0.029) when compared with CagA-negative patients. Interestingly, whereas serum glucose, LDL levels, anti-urease B, and anti-CagA antibodies were predictors of extent score at univariate analysis, at multivariate analysis anti-CagA antibody titer only was an independent predictor of the extent of coronary atherosclerosis (B=0.051, standard error of B=0.042, P=0.04).

CONCLUSION

These results support the association between CagA-positive H. pylori infection and coronary atherosclerotic burden. Further studies are needed to better elucidate the mechanism by which CagA-positive strains may promote atherosclerosis.

Novel Helicobacter pylori therapeutic targets: the unusual suspects

Understanding the current status of the discovery and development of anti-Helicobacter therapies requires an overview of the searches for therapeutic targets performed to date. A summary is given of the very substantial body of work conducted in the quest to find Helicobacter pylori genes that could be suitable candidates for therapeutic intervention. The products of most of these genes perform metabolic functions, and others have roles in growth, cell motility and colonization. The genes identified as potential targets have been organized into three categories according to their degree of characterization. A short description and evaluation is provided of the main candidates in each category. Investigations of potential therapeutic targets have generated a wealth of information about the physiology and genetics of H. pylori, and its interactions with the host, but have yielded little by way of new therapies.

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.

Associations of plasma IL-8 levels withHelicobacter pyloriseropositivity, gastric atrophy, andIL-8T-251A genotypes

There are few data on circulatory pro-inflammatory cytokine levels and cytokine gene polymorphisms inH. pylori-positive patients. A cross-sectional study was conducted to examine the effects ofH. pyloriinfection, gastric atrophy, and theIL-8T-251A polymorphism on plasma IL-8 levels in 98 Japanese adults. Seventy-one subjects were positive forH. pyloriinfection. The geometric mean of plasma IL-8 concentration was significantly higher in subjects withH. pyloriinfection than in those without (P=0·001). The development of atrophy was negatively associated with IL-8 levels in theH. pylori-positive subjects, although not significantly. Plasma IL-8 levels in the T/T genotype were associated withH. pyloriinfection and atrophy status (P=0·016). Our findings suggested that circulating IL-8 levels were associated withH. pyloriinfection. The effect ofH. pyloriinfection on plasma IL-8 levels was not clearly modified by theIL-8T-251A polymorphism.

[The role of Helicobacter pylori infection in children with chronic immune thrombocytopenic purpura]

Helicobacter pylori infection has been associated with immune thrombocytopenic purpura in adults, however, the few studies concerning this issue showed conflicting results in the paediatric field. Therefore, authors prospectively investigated the incidence of Helicobacter pylori infection and the effect of Helicobacter pylori eradication on platelet count recovery in children with immune thrombocytopenic purpura.

PATIENTS AND METHODS

The study included 27 children with immune thrombocytopenic purpura (13 boys and 14 girls) with a median age of 8.2 years (range, 18 months-18 years). 38 healthy children (controls) were also enrolled (20 boys, 18 girls, median age, 9.6 years, range, 4-18 years). Helicobacter pylori infection was diagnosed using 13 C urea breath test. Eradication was assessed at 6 weeks following the end of the treatment by 13 C urea breath.

RESULTS

2 children out of 27 patients with immune thrombocytopenic purpura proved to be positive for Helicobacter pylori infection (7.7%) and were treated with combination therapy. Controls showed similar rate of Helicobacter pylori infection (3/38, 7.9%) in comparison to those with immune thrombocytopenic purpura. In the follow-up period (mean, 10 months, range, 6-14 months) platelets did not show any improvement in infected children following the eradication treatment and were identical to those of the uninfected patients. Eradication was successful in the 2 Helicobacter pylori infected patients with immune thrombocytopenic purpura.

CONCLUSION

The results do not suggest a pathogenetic role of Helicobacter pylori infection in the etiology of immune thrombocytopenic purpura. Screening of Helicobacter pylori infection among paediatric patients with immune thrombocytopenic purpura is not recommended.