Helicobacter pylori and autoimmune disease: Cause or bystander

Helicobacter pylori infection and risk of multiple sclerosis: an updated meta-analysis

Numerous studies have proposed that Helicobacter pylori infection may possess a protective effect in terms of future risk of multiple sclerosis (MS), however is poorly evidenced. We performed a systematic review and meta-analysis to obtain the pooled results regarding the prevalence of H. pylori infection in persons with multiple sclerosis (pwMS) and healthy controls. A comprehensive database search was performed in PubMed, Embase, and medRxiv for all relevant literature published from the inception of the databases until the August 1, 2022. The retrieved articles were first screened by title and abstract, followed by full-text screening based on the pre-established eligibility criteria. The risk of bias was assessed using the ROBINS-I tool. Data on the seroprevalence of H. pylori in pwMS and healthy controls was extracted, and a meta-analysis was performed in Review Manager Version 5.4.1. Sub-group analysis was performed in accordance with the geographical distribution (Eastern and Western countries) and the method of detection of H. pylori infection enzyme-linked-immunoassay (ELISA), Immunofluorescence, Immunochromatography). Furthermore, sensitivity analyses and publication bias were determined. The preliminary database search retrieved a total of 822 studies. Seventeen case-control studies with a total of 2721 pwMS and 2245 controls were included as a final sample size for the meta-analysis. The overall risk of bias was moderate. Overall, the rate of H. pylori infection in pwMS was not significantly different than in healthy controls (OR: 0.79 (95% CI = 0.58-1.08); I2 = 79%, p = 0.14). Subgroup analysis revealed that the rate of H. pylori infection among PwMS was not significant in both Eastern and Western countries (OR: 0.75 (95% CI = 0.52-1.08); I2 = 81%, p = 0.12). In contrast, data revealed that the prevalence of H. pylori infection in pwMS was significantly lower than that of control based on studies utilizing ELISA assays detection (OR: 0.71 (95% CI = 0.50-1.00); I2 = 81%, p = 0.05), while no significant difference was seen on studies using other assays than ELISA (OR: 1.19 (95% CI = 0.81-1.77); I2 = 0%, p = 0.38). Our findings of statistically indifferent prevalence of H. pylori infection as compared between pwMS and healthy controls suggested the absence of protective effect for risk of MS following H. pylori infection.

Helicobacter pylori in gastrointestinal manifestation of systemic sclerosis

Aim

To study the prevalence of Helicobacter pylori in systemic sclerosis patients and its gastrointestinal manifestations in comparison with Helicobacter pylori-negative systemic sclerosis patients. Systemic sclerosis gastrointestinal outcome post Helicobacter pylori eradication was evaluated.

Method

In total, 70 systemic sclerosis patients and 70 age-, gender- and race-matched healthy controls had their urea breath test done. Gastrointestinal manifestations in systemic sclerosis were assessed using University of California at Los Angeles 2.0 and Leeds Dyspepsia Questionnaire questionnaires. Systemic sclerosis patients with confirmed Helicobacter pylori infection were given standard Helicobacter pylori eradication therapy. Urea breath test was repeated 6 weeks posteradication therapy with their gastrointestinal symptoms reassessed.

Results

The prevalence of Helicobacter pylori was low in both systemic sclerosis patients (10%) and healthy controls (2.9%). There was no significant difference in gastrointestinal symptoms between Helicobacter pylori-positive and Helicobacter pylori-negative systemic sclerosis patients. However, the Helicobacter pylori-positive patients reported higher median severity scores for the gastrointestinal symptoms of reflux (0.5 vs 0.35), abdominal distension (1.5 vs 0.75) and social functioning impairment score (0.5 vs 0.16) using the University of California at Los Angeles 2.0 score. The Helicobacter pylori-positive patients also indicated increased upper abdominal pain (3.0 vs 0.0), regurgitation (2.0 vs 0.0) and burping (3.0 vs 0.0), observed from the Leeds Dyspepsia Questionnaire scores. Gastrointestinal outcomes post-Helicobacter pylori eradication showed either an improvement or complete resolution of symptoms.

Conclusion

Gastrointestinal symptoms in systemic sclerosis patients are unlikely to be caused by Helicobacter pylori in the recent years in our cohort of patients. No significant difference in gastrointestinal symptoms was seen between Helicobacter pylori-positive and Helicobacter pylori-negative systemic sclerosis patients. Helicobacter pylori can be readily tested by urea breath test to look for present infection.

A laboratory-based cross-sectional study about helicobacter pylori infection and diabetes

Background

Despite the numerous articles discussing the relationship between diabetes mellitus type 2 (DMT2) and chronic Helicobacter pylori (H. pylori) infection the results have been inconsistent, necessitating further research. This study investigated the coexistence of Helicobacter pylori infection and DMT2.

Methods

We conducted a study in selected laboratories in Tehran, measuring the H.Pylori stool antigen (HpSA) in individuals referred by physicians for a glycosylated hemoglobin A1c (HbA1c) test.

Results

Out of the 2500 patients who were referred to randomly selected laboratories, a total of 2025 (81%) patients had serum HbA1c levels above 6.5%. of 2025 patients with HbA1c levels above 6.5%, 1321 (52.84%) had HpSA in their stool. No significant gender difference was observed, with a mean age ± SD, 48.65 ± 7.55. HpSA was positive in 52.84% of the DM group, while in the non-DM group, HpSA was positive in 37.36% of cases. Fecal antigen titers are not related to gender (P = 0.274) but are related to age (r = 0.213, P=0.034).

Conclusion

Long-term infection with Helicobacter pylori may be significantly associated with elevated HgA1c.Testing for H. pylori infection, regular monitoring of blood sugar and HbA1c levels in high-risk people can prevent DMT2.

Clinical characteristics and risk factors of Helicobacter pylori infection-associated Sjogren's syndrome

OBJECTIVE

Although infectious pathogens are predominant factors for inducing and maintaining immune system disorders, there exist few reports establishing the significant correlation between Helicobacter pylori (H. pylori) infection and Sjogren's syndrome. This study aims to demonstrate the correlation between Sjogren's syndrome and H. pylori infection in patients, highlighting various clinical characteristics and risk factors.

METHODS

A single-center retrospective observational study was conducted in patients (n = 224) admitted from January 1, 2012, to February 10, 2021, in the First Affiliated Hospital of Wenzhou Medical University (Wenzhou, China). All the recruited subjects with Sjogren's syndrome and H. pylori infection were only included by validating the available medical records online.

RESULTS

In this study, a total of 224 patients from January 1, 2012, to February 10, 2021, were diagnosed with Sjogren's syndrome. Among them, 94 patients (41.96%) with Sjogren's syndrome were infected with H. pylori. Accordingly, the clinical manifestations, serological and immunological characteristics, as well as gastroscopic biopsy outcomes of the recruited patients with primary Sjogren's syndrome (pSS) were reported. The multivariable analysis of the dry syndrome patients infected with H. pylori displayed hypergammaglobulinemia (odds ratio [OR], 0.354; 95% confidence interval [CI], 0.189-0.663), total cholesterol (OR, 1.158; 95% CI, 0.856-1.550), hypertension (OR, 0.227; 95% CI, 0.114-0.455), Female sex (OR, 5.778; 95% CI, 1.458-22.9), anti-SSA/Ro60 positive (OR, 2.384; 95% CI, 233-4.645), γ-GT (OR, 0.99; 95% CI, 0.99-1.00) and alkaline phosphatase (ALP, OR, 1.00; 95% CI, 0.99-1.00) levels.

CONCLUSION

Together, our findings demonstrated that hypergammaglobulinemia could be the independent risk factors of H. pylori infection in patients with Sjogren's syndrome, requiring the physician's advice in the future.

Influence of Helicobacter pylori infection on risk of rheumatoid arthritis: a nationwide population-based study

The relationship between Helicobacter pylori infection and rheumatoid arthritis has been investigated, but the results remain controversial. This study aims to determine the association between the two diseases via a 17-year retrospective cohort study. Using the National Health Insurance Research Database, a nationwide population based in Taiwan, we identified 97,533 individuals with H. pylori infection and matched controls between 2000 and 2017 using propensity score matching at a 1:1 ratio. The adjusted hazard ratio of rheumatoid arthritis was determined by multiple Cox regression. The incidence rate of rheumatoid arthritis was 1.28 per 10,000 person-months in the H. pylori cohort, with a higher risk compared to the control group. In the < 30 years old subgroup, the risk was highest, especially in women < 30 years old with H. pylori infection. Patients with < 1 year follow-up showed 1.58 times higher susceptibility to rheumatoid arthritis. Individuals with follow-ups of 1-5 years and over 5 years demonstrated 1.43 and 1.44 times higher risks of rheumatoid arthritis, respectively. Our study showed H. pylori infection was associated with the development of rheumatoid arthritis. Clinicians should note higher risk, especially < 30 years old. More research needed to understand underlying mechanism.

Association of Helicobacter pylori Infection with Autoimmune Thyroid Disease in the Female Sex

BACKGROUND

Helicobacter pylori infection has been associated with an increased risk of thyroid diseases (TDs), although scientific evidence is conflicting. In the present study the relationship between TDs, including both autoimmune (AI) and non-autoimmune TD, and H. pylori infection was investigated.

METHODS

Data from records of patients undergoing upper endoscopy and histologically evaluated for H. pylori infection were retrieved. In addition to demographic information, the features of gastritis based on non-targeted biopsies collected from the antrum, angulus, and corpus were analyzed. The presence of H. pylori infection and atrophy and/or metaplasia and/or dysplasia in at least one gastric specimen was defined as a long-lasting H. pylori infection and the presence of a chronic-active gastritis as a current infection. Hashimoto's and Graves' diseases were included in the AITD group, and thyroid nodules, goiter, iatrogenic thyroid hypo/hyper function, and thyroidectomy in the non-autoimmune TD group.

RESULTS

A total of 8322 records from adult patients from Northern Sardinia, characterized by a similar genetic background, was analyzed. Participants were aged 18-93 years (females 5339, 64.1%), and more specifically, 562 (6.7%) had a diagnosis of AITD and 448 (5.4%) of non-autoimmune TD. A significant association between long-lasting H. pylori and AITD (OR 1.34; 95%CI 1.13-1.60) was found, irrespective of age, sex, body mass index, and smoking status, while it was not associated with non-autoimmune TD. Current H. pylori infection did not show significant ORs for AITD (OR 0.99; 95%CI 0.64-1.57) and non-autoimmune TD (OR 0.86; 95%CI 0.66-1.15). The association with long-lasting H. pylori infection was confirmed to be significant for both Hashimoto's thyroiditis and Graves' disease by multivariable regression analysis. Stratification according to sex revealed a significant association only for females (OR 1.39; 95%CI 1.12-1.72).

CONCLUSIONS

Our results indicate that long-lasting H. pylori infection is associated with AITD in the female adult population of Northern Sardinia.

The possible role of Helicobacter pylori in liver diseases

According to previous studies, Helicobacter pylori infection is associated with liver disease. In order to better understand the risk of acquiring various liver diseases, we reviewed current knowledge on the impact of H. pylori on the onset, intensification, and progression of various liver diseases caused by the infection of H. pylori. It has been estimated that between 50 and 90% of people worldwide have been infected with H. pylori. The bacterium is mostly responsible for inflamed gastric mucosa, ulcers, and cancers associated with the gastric mucosa. Through the active antioxidant system in H. pylori, the bacteria can neutralize free radicals by synthesizing VacA, a toxin that causes cell damage and apoptosis. Furthermore, there is a possibility that CagA genes may play a role in cancer development. People who have been infected with H. pylori are likely to develop lesions in the skin, the circulation system, and the pancreas. Moreover, transferring blood from the stomach may allow H. pylori to colonize the liver. The bacterium worsened liver function during autoimmune inflammation, toxic injury, chronic HCV infection, chronic HBV infection, and liver cirrhosis. Increasing portal pressure, hyperammonemia, and esophageal varices may be associated with H pylori infection. As a result, it is crucial to diagnose and treat this infection in patients with H. pylori.

Update in Molecular Aspects and Diagnosis of Autoimmune Gastritis

Recent studies have advanced our understanding of the pathophysiology of autoimmune gastritis, particularly its molecular aspects. The most noteworthy recent advancement lies in the identification of several candidate genes implicated in the pathogenesis of pernicious anemia through genome-wide association studies. These genes include PTPN22, PNPT1, HLA-DQB1, and IL2RA. Recent studies have also directed attention towards other genes such as ATP4A, ATP4B, AIRE, SLC26A7, SLC26A9, and BACH2 polymorphism. In-depth investigations have been conducted on lymphocytes and cytokines, including T helper 17 cells, interleukin (IL)-17A, IL-17E, IL-17F, IL-21, IL-19, tumor necrosis factor-α, IL-15, transforming growth factor-β1, IL-13, and diminished levels of IL-27. Animal studies have explored the involvement of roseolovirus and H. pylori in relation to the onset of the disease and the process of carcinogenesis, respectively. Recent studies have comprehensively examined the involvement of autoantibodies, serum pepsinogen, and esophagogastroduodenoscopy in the diagnosis of autoimmune gastritis. The current focus lies on individuals demonstrating atypical presentations of the disease, including those diagnosed in childhood, those yielding negative results for autoantibodies, and those lacking the typical endoscopic characteristics of mucosal atrophy. Here, we discuss the recent developments in this field, focusing on genetic predisposition, epigenetic modifications, lymphocytes, cytokines, oxidative stress, infectious agents, proteins, microRNAs, autoantibodies, serum pepsinogen, gastrin, esophagogastroduodenoscopy and microscopic findings, and the risk of gastric neoplasm.

Regulatory B cells (Bregs) in Helicobacter pylori chronic infection

BACKGROUND

Helicobacter pylori (H. pylori) infection is linked with a wide variety of diseases and was reported in more than half of the world's population. Chronic H. pylori infection and its final clinical outcome depend mainly on the bacterial virulence factors and its ability to manipulate and adapt to human immune responses. Bregs blood levels have been correlated with increased bacterial load and infection chronicity, especially Gram-negative bacterial infection. This study aimed to identify prevalence and virulence factors of chronic H. pylori infection among symptomatic Egyptian patients and to examine its possible correlation to levels of regulatory B cells (Bregs) in blood.

MATERIALS AND METHODS

Gastric biopsies and blood samples from each of 113 adult patients, who underwent upper endoscopy, were examined for the detection of H. pylori by culture and PCR methods. Conventional PCR was used to determine various virulent genes prevalence and association to clinical outcome. Flow cytometry was used to evaluate Bregs levels.

RESULTS

Helicobacter pylori prevalence was 49.1% (55/112). Regarding virulence genes incidence, flaA gene was detected in 73% (40/55), vir B11 in 56.4% (31/55), hopZ1 in 34.5% (19/55), hopZ2 in 89% (49/55), babA2 in 52.7% (29/55), dupA jhp917 in 61.8% (34/55), vacA m1/m2 in 70.9% (39/55), and vacA s1/s2 in 69% (38/55) strains. Bregs levels were significantly lower in H. pylori-infected patients (p = 0.013), while total leukocyte count (TLC) showed no significant differences.

CONCLUSION

Helicobacter pylori infection prevalence was almost 49%, and the infection was found to be related to inflammatory conditions as gastritis and ulcers rather than malignant transformations. Also, we found that CD24⁺ CD38⁺ B cells were downregulated in H. pylori-infected patients.

HELICOBACTER AND HEPATOBILIARY DISEASES: UPDATE 2023

•Clinical studies have shown that hepatobiliary diseases of inflammatory and neoplastic origin are associated with Helicobacter infection. •Translocation and the ascending pathway are putative mechanisms for Helicobacter spp to enter the hepatobiliary system. •H. pylori infection has a systemic effect through the activity of pro-inflammatory cytokines, TNF-α, leukotrienes, interferon-β, interferon-γ, and acute phase proteins. •Histopathological confirmation is needed to present that H. pylori eradication prevents or improves hepatobiliary disease progression. Helicobacter Pylori (H. pylori) is one of the main infectious causes of gastroduodenal diseases, however, its role in developing different extragastric diseases has been proven. The possible involvement of H. pylori in the pathogenesis of cardiovascular, metabolic, neurodegenerative, skin, and hepatobiliary diseases is suggested. The bacterium has been found in tissue samples from the liver, biliary tract, and gallstones of animals and humans. However, the role of H. pylori infection in the pathogenesis of liver and biliary diseases has not been finally established. The histopathological confirmation of the positive effect of H. pylori eradication is needed. In addition, there are discussions on the clinical significance of other Helicobacter species. The review presents the data available for and against the involvement of H. pylori in hepatobi-liary disease development and progression.

Vitamin B12 levels in thyroid disorders: A systematic review and meta-analysis

Background and aims

Numerous studies have found an association between vitamin deficiency and thyroid disorders (TD). The presence of anti-parietal cell antibodies is indicative of reduced ability to absorb vitamin B12. Thus, this study reviewed the existing studies with the objective of assessing differences in the serum levels of vitamin B12 among patients with and without TD, the frequency of vitamin B12 deficiency in patients with TD, and the presence of anti-parietal cell antibodies in patients with TD.

Methods

A meta-analysis of random-effects model was conducted to calculate pooled frequencies, mean differences (MD), and their respective 95% confidence intervals (CI). We identified 64 studies that met our inclusion criteria (n = 28597).

Results

We found that patients with hypothyroidism had lower vitamin B12 levels than healthy participants (MD: -60.67 pg/mL; 95% CI: -107.31 to -14.03 pg/mL; p = 0.01). No significant differences in vitamin B12 levels were observed between healthy participants and patients with hyperthyroidism (p = 0.78), autoimmune thyroid disease (AITD) (p = 0.22), or subclinical hypothyroidism (SH) (p = 0.79). The frequencies of vitamin B12 deficiency among patients with hypothyroidism, hyperthyroidism, SH, and AITD were 27%, 6%, 27%, and 18%, respectively.

Conclusions

Patients with hypothyroidism had lower levels of vitamin B12 than healthy participants. No significant differences were observed between vitamin B12 levels and hyperthyroidism, AITD, or SH.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=324422, identifier (CRD42022324422).

Contribution of Helicobacter pylori to the Inflammatory Complications of Common Variable Immunodeficiency

Common Variable Immunodeficiency (CVID), the most prevalent symptomatic primary immunodeficiency, is frequently associated with severe inflammatory complications that determine its morbidity and mortality. We hypothesize that Helicobacter pylori (HP), a very common worldwide infection, may contribute to the clinical and immune phenotype of CVID. We stratified 41 CVID patients into HP+ (n=26) and HPneg (n=15) groups, according to previous urease breath test and/or gastric biopsies, and compared their clinical manifestations and immune profile evaluated by flow cytometry. No genetic variants with known potential impact in HP infection were found upon WES/WGS. Gastric complications were significantly more frequent in HP+ patients. Importantly, the six CVID patients with gastric cancer were infected with HP. In contrast, a significantly higher frequency of cytopenias was observed in the HPneg. Moreover, HP+ did not feature higher prevalence of organ auto-immunity, as well as of lung, liver or intestinal inflammatory manifestations. We observed the same B-cell profiles in HP+ and HPneg groups, accompanied by marked CD4 and CD8 T-cell activation, increased IFNγ production, and contraction of naïve compartments. Notably, HP+ patients featured low CD25 despite preserved Foxp3 levels in CD4 T cells. Overall, HP impact in CVID inflammatory complications was mainly restricted to the gastric mucosa, contributing to increased incidence of early onset gastric cancer. Thus, early HP screening and eradication should be performed in all CVID patients irrespective of symptoms.

Helicobacter Pylori and Autoimmune Diseases: Involving Multiple Systems

The modern Gastroenterology have witnessed an essential stride since Helicobacter pylori was first found in the stomach and then its pathogenic effect was discovered. According to the researches conducted during the nearly 40 years, it has been found that this bacterium is associated with a natural history of many upper gastrointestinal diseases. Epidemiological data show an increased incidence of autoimmune disorders with or after infection with specific microorganisms. The researches have revealed that H. pylori is a potential trigger of gastric autoimmunity, and it may be associated with other autoimmune diseases, both innate and acquired. This paper reviews the current support or opposition about H. pylori as the role of potential triggers of autoimmune diseases, including inflammatory bowel disease, autoimmune thyroiditis, type 1 diabetes mellitus, autoimmune liver diseases, rheumatoid arthritis, idiopathic thrombocytopenic purpura, systemic lupus erythematosus, as well as Sjogren’s syndrome, chronic urticaria and psoriasis, and tried to explain the possible mechanisms.

Infectious Uveitis in Horses and New Insights in Its Leptospiral Biofilm-Related Pathogenesis

Uveitis is a sight-threatening eye disease in equids known worldwide that leads to considerable pain and suffering. By far the most common type of uveitis in Germany and neighboring countries is classical equine recurrent uveitis (ERU), which is caused by chronic intraocular leptospiral infection and is the main cause of infectious uveitis in horses. Other infectious causes are extremely rare and are usually clinically distinguishable from ERU. ERU can be treated very effectively by vitreous cavity lavage (vitrectomy). For proper indications of this demanding surgery, it is necessary to differentiate ERU from other types of uveitis in which vitrectomy is not helpful. This can be conducted on the basis of anamnesis in combination with ophthalmologic findings and by aqueous humor examination. During vitrectomy, vitreous material is obtained. These vitreous samples have historically been used for numerous etiologic studies. In this way, a chronic intraocular leptospiral infection has been shown to be the cause of typical ERU and, among other findings, ERU has also been recognized as a biofilm infection, providing new insights into the pathogenesis of ERU and explaining some thus far unexplainable phenomena of ERU. ERU may not only have transmissible aspects to some types of uveitis in humans but may also serve as a model for a spontaneously occurring biofilm infection. Vitreous material obtained during therapeutically indicated vitrectomy can be used for further studies on in vivo biofilm formation, biofilm composition and possible therapeutic approaches.

Two Distinct Etiologies of Gastric Cancer: Infection and Autoimmunity

Gastric cancer is a leading cause of mortality worldwide. The risk of developing gastric adenocarcinoma, which comprises >90% of gastric cancers, is multifactorial, but most associated with Helicobacter pylori infection. Autoimmune gastritis is a chronic autoinflammatory syndrome where self-reactive immune cells are activated by gastric epithelial cell autoantigens. This cause of gastritis is more so associated with the development of neuroendocrine tumors. However, in both autoimmune and infection-induced gastritis, high risk metaplastic lesions develop within the gastric mucosa. This warrants concern for carcinogenesis in both inflammatory settings. There are many similarities and differences in disease progression between these two etiologies of chronic gastritis. Both diseases have an increased risk of gastric adenocarcinoma development, but each have their own unique comorbidities. Autoimmune gastritis is a primary cause of pernicious anemia, whereas chronic infection typically causes gastrointestinal ulceration. Both immune responses are driven by T cells, primarily CD4⁺ T cells of the IFN-γ producing, Th1 phenotype. Neutrophilic infiltrates help clear H. pylori infection, but neutrophils are not necessarily recruited in the autoimmune setting. There have also been hypotheses that infection with H. pylori initiates autoimmune gastritis, but the literature is far from definitive with evidence of infection-independent autoimmune gastric disease. Gastric cancer incidence is increasing among young women in the United States, a population at higher risk of developing autoimmune disease, and H. pylori infection rates are falling. Therefore, a better understanding of these two chronic inflammatory diseases is needed to identify their roles in initiating gastric cancer.

Helicobacter pylori antibodies and multiple sclerosis: a single-center study and a short review of the literature

Background

Multiple sclerosis is an immune-mediated disease which has been associated to a great variety of mechanisms that could influence its pathogenesis. Numerous reports in the medical literature suggest that Helicobacter pylori may be a mediator of the disease. However, it is unknown if there is any clear association between MS and HP.

Results

We studied 144 persons with multiple sclerosis prospectively enrolled in our hematopoietic stem cell transplantation program. In 144 persons, 14% patients were positive for IgG-HP whereas 86% were negative, 8.3% pwMS were IgM-HP positive while 91.6% pwMS were negative, 18% patients were positive and 82% negative for IgA-HP. Significantly lower concentrations of anti-HP IgG were found in RRMS in comparison with SPMS (− 28.5, 95% CI 4.3–52.7). While concentrations of anti-HP IgA were significantly lower in SPMS in comparison with RRMS (0.54, 95% CI 0.1–0.9). In a multivariate analysis, positivity rate of anti-HP IgG was found to be higher in SPMS patients (OR 4.7, 95% CI 1.1–19.6).

Conclusions

There was a negative correlation between the presence of anti-HP antibodies and MS. Further larger studies with specific laboratory testing methods are needed to discard or confirm the potential role of anti-HP antibodies as protective for MS.

Helicobacter pylori and its association with autoimmune diseases: systemic lupus erythematosus, rheumatoid arthritis and Sjögren syndrome

Helicobacter pylori (H. pylori) is a gram-negative bacterium that adapts to the gastric mucosa and provokes symptoms associated with gastritis. Chronic H. pylori infection in patients with a genetic predisposition can trigger autoimmune diseases due to the immune interaction of cellular and humoral responses. Infections are a triggering factor for systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and Sjögren syndrome (SS), although the association between H. pylori and these diseases is unclear. Therefore, we reviewed this interaction and its clinical importance.

Role of Toll-Like Receptors in Neuroimmune Diseases: Therapeutic Targets and Problems

Toll-like receptors (TLRs) are a class of proteins playing a key role in innate and adaptive immune responses. TLRs are involved in the development and progression of neuroimmune diseases via initiating inflammatory responses. Thus, targeting TLRs signaling pathway may be considered as a potential therapy for neuroimmune diseases. However, the role of TLRs is elusive and complex in neuroimmune diseases. In addition to the inadequate immune response of TLRs inhibitors in the experiments, the recent studies also demonstrated that partial activation of TLRs is conducive to the production of anti-inflammatory factors and nervous system repair. Exploring the mechanism of TLRs in neuroimmune diseases and combining with developing the emerging drug may conquer neuroimmune diseases in the future. Herein, we provide an overview of the role of TLRs in several neuroimmune diseases, including multiple sclerosis, neuromyelitis optica spectrum disorder, Guillain-Barré syndrome and myasthenia gravis. Emerging difficulties and potential solutions in clinical application of TLRs inhibitors will also be discussed.

Insights into the knowledge of complex diseases: Environmental infectious/toxic agents as potential etiopathogenetic factors of systemic sclerosis

Systemic sclerosis (SSc) is a connective tissue disease secondary to three cardinal pathological features: immune-system alterations, diffuse microangiopathy, and fibrosis involving the skin and internal organs. The etiology of SSc remains quite obscure; it may encompass multiple host genetic and environmental -infectious/chemical-factors. The present review focused on the potential role of environmental agents in the etiopathogenesis of SSc based on epidemiological, clinical, and laboratory investigations previously published in the world literature. Among infectious agents, some viruses that may persist and reactivate in infected individuals, namely human cytomegalovirus (HCMV), human herpesvirus-6 (HHV-6), and parvovirus B19 (B19V), and retroviruses have been proposed as potential causative agents of SSc. These viruses share a number of biological activities and consequent pathological alterations, such as endothelial dysfunction and/or fibroblast activation. Moreover, the acute worsening of pre-existing interstitial lung involvement observed in SSc patients with symptomatic SARS-CoV-2 infection might suggest a potential role of this virus in the overall disease outcome. A variety of chemical/occupational agents might be regarded as putative etiological factors of SSc. In this setting, the SSc complicating silica dust exposure represents one of the most promising models of study. Considering the complexity of SSc pathogenesis, none of suggested causative factors may explain the appearance of the whole SSc; it is likely that the disease is the result of a multifactorial and multistep pathogenetic process. A variable combination of potential etiological factors may modulate the appearance of different clinical phenotypes detectable in individual scleroderma patients. The in-deep investigations on the SSc etiopathogenesis may provide useful insights in the broad field of human diseases characterized by diffuse microangiopathy or altered fibrogenesis.

Helicobacter pylori Infection and Extragastric Diseases-A Focus on the Central Nervous System

Helicobacter pylori (H. pylori) is most known to cause a wide spectrum of gastrointestinal impairments; however, an increasing number of studies indicates that H. pylori infection might be involved in numerous extragastric diseases such as neurological, dermatological, hematologic, ocular, cardiovascular, metabolic, hepatobiliary, or even allergic diseases. In this review, we focused on the nervous system and aimed to summarize the findings regarding H. pylori infection and its involvement in the induction/progression of neurological disorders. Neurological impairments induced by H. pylori infection are primarily due to impairments in the gut-brain axis (GBA) and to an altered gut microbiota facilitated by H. pylori colonization. Currently, regarding a potential relationship between Helicobacter infection and neurological disorders, most of the studies are mainly focused on H. pylori.

Microbiome Metabolites and Thyroid Dysfunction

Thyroid diseases are common conditions that have a negative impact on the health of all populations. The literature sheds light on the differences in the composition of the intestinal microbiota in patients suffering from thyroid diseases compared to healthy individuals. The microbiome affects the proper functioning of the thyroid gland, and the existence of the gut–thyroid axis is discussed in the context of both thyroid diseases and intestinal dysbiosis. The purpose of this review is to describe associations between the microbiome and its metabolites and thyroid dysfunction. We try to explain the role of the microbiome in the metabolism of thyroid hormones and the impact of thyroid autoimmune diseases. In addition, we raise issues related to the influence of bacterial metabolites, such as short-chain fatty acids or secondary bile acids, in the functioning of the thyroid gland. Last but not least, we explored the interactions between the gut microbiota and therapeutics and supplements typically administered to patients with thyroid diseases.

Ultrasonographic assessment of femoral cartilage thickness in patients with Helicobacter pylori infection

OBJECTIVES

Helicobacter pylori is a major cause of gastritis and a potential trigger of inflammatory disease. The effect of H pylori infection on distal femoral cartilage has yet to be evaluated. The aim of this study was to evaluate femoral cartilage thickness in patients with H pylori infection and to find whether this infection affects femoral cartilage thickness.

METHODS

This cross-sectional study included 199 patients. To measure the thickness of femoral articular cartilage, 99 patients with H pylori infections and 100 with H pylori-negative controls were enrolled into two groups. The measurements were made using linear probe ultrasonography with the patients in supine positions and their knees in maximum flexion. Demographic, clinical, endoscopic and laboratory data were collected for all patients.

RESULTS

Both the right and left femoral condyles had thinner cartilage thickness in the H pylori-positive group than in the H pylori-negative group (P = .016, P = .036). For the intercondylar area and lateral femoral condyles, although the H pylori-positive patients had thinner femoral cartilage thickness than the H pylori-negative individuals for both extremities, this finding was not statistically significant (P > .05).

CONCLUSION

Femoral cartilage was thinner in patients with H pylori than patients without H pylori for right and left medial femoral condyles. This study suggests that H pylori infections may affect femoral cartilage thickness and potentially increase the risk of cartilage degeneration.

Inverse Association Between Helicobacter pylori Infection and Unexplained Isolated Terminal Ileitis: A Retrospective Study

Background

Isolated terminal ileitis (ITI) is a phenomenon often observed during colonoscopy, but in most cases, the specific etiology of ITI is unclear. Helicobacter pylori (H. pylori) infection has been reported to be associated with a wide variety of diseases, especially gastrointestinal diseases. Here, we conducted a retrospective study to explore a potential correlation between H. pylori infection and unexplained ITI (UITI).

Materials and Methods

The retrospective study was conducted at Sino-French New City Branch of Tongji Hospital, Wuhan, China, from April 2017 to October 2020. All subjects underwent total colonoscopy, with the endoscope being inserted more than 10cm into the terminal ileum. Subjects also received a ¹³C-urea breath test (¹³C-UBT). Data on the age, gender, endoscopic manifestations, and main clinical symptoms of subjects were collected. The presence of H. pylori infection was defined as a positive ¹³C-UBT result. Logistic regression models were used to analyze the potential correlation between H. pylori infection and UITI.

Results

There were 247 subjects (25.1%) in the H. pylori (+) group and 739 subjects (74.9%) in the H. pylori (-) group. The prevalence of UITI in the H. pylori (+) group was significantly lower than that in the H. pylori (-) group (OR = 0.518; 95% CI 0.281-0.956; P = 0.035), and there was no difference in other clinical features between groups. Stratification analysis results showed that there was an inverse association between H. pylori infection and UITI in subjects with age <60 (P = 0.046).

Conclusion

These data showed that H. pylori infection was negatively correlated with UITI. Additional studies are needed to validate these findings in a larger cohort as well as to explore the underlying mechanisms.

The Correlation between Helicobacter Pylori Infection and Disease Severity in Patients with Systemic Sclerosis

BACKGROUND Systemic sclerosis (SSc) is a relatively common connective tissue disease, which is characterized by inflammation, progressive skin fibrosis, and injuries of small vessels, particularly in the lung and kidney. It seems that Helicobacter pylori (H. pylori) might contribute to the development of SSc as an extra-gastrointestinal autoimmune disease. We investigated the association between H. pylori infections and disease severity in patients with SSc. METHODS This is a cross-sectional study. Sampling method in this study was census method in such a way that all patients with SSc referred to Imam Reza Education and Research University Medical Center from May 2015 to August 2016 were included in the study. Finally, 74 patients were selected based on the inclusion criteria. Inclusion criteria were: 1. Definitive SSc based on American College of Rheumatology/ European League Against Rheumatism 2010 (ACR/EULAR) classification for scleroderma, which was diagnosed within the last two years. 2. Not taking any proton pump inhibitors. 3. Not taking any H. pylori treatment with a standard regimen within the recent 2 months. Disease severity was assessed and determined by two rheumatologists based on the Medsger's Disease Severity Scale (MDSS). H. pylori stool antigen was evaluated based on the test which sensitivity and specificity was proven. All obtained data were statistically analyzed by SPSS 16 using Fisher's exact test Spearman correlation test (RSpearman). RESULTS Forty one (55.4%) of the 74 patients had positive stool antigens. We found a significant positive association between the severity of disease based on MDSS and titer of H. pylori stool antigen (p ≤ 0.001). CONCLUSION This study reveals that H. pylori infection may play a significant role in the severity of organ involvement in SSc.

Low Titer Tissue Transglutaminase Antibodies: A Link to Helicobacter pylori Infection?

INTRODUCTION

Low serum titer of anti-tissue transglutaminase (tTG) has been described in various conditions without any evidence of celiac disease (CD). Infectious agents have been suggested to trigger autoimmunity and promote the production of anti-tTG. The aim of this study was to investigate if there is a link between a positive celiac serology and concomitant Helicobacter pylori infection in children.

METHODS

The data of 178 pediatric patients who underwent upper gastrointestinal endoscopy due to positive celiac serology were compiled. The patients whose histopathologic findings were not consistent with CD were followed on gluten-containing diet. The changes in the serum level of anti-tTG IgA on the follow-up were compared between H. pylori-infected and noninfected patients after the eradication of H. pylori.

RESULTS

Of 155 patients who met the inclusion criteria, 119 (group 1) were diagnosed as CD, and duodenal histopathology of the remaining 36 children (group 2) was not compatible with CD. In group 2, 11 out of 36 (30.5%) patients were infected with H. pylori. After the eradication of H. pylori, anti-tTG IgA level either decreased or dropped below cutoff value in 9/11 (81%) patients while it was 20% in those who were not infected with H. pylori in the 6th month of the follow-up (p = 0.001).

CONCLUSION

Our results suggest that H. pylori infection may be the cause of false or transient positive celiac serology. Thus, a positive celiac serology should be carefully interpreted in the presence of H. pylori infection before confirming the diagnosis of this life-long disease.

40 Years of Helicobacter pylori: A Revolution in Biomedical Thought

Background: Various microorganisms such as bacteria, virus, and fungi can infect humans and cause not just a simple infection but septic conditions, organ dysfunction, and precancerous conditions or cancer involving various organ systems. After the discovery of the microscope, it was easier to discover and study such microorganisms, as in the case of Helicobacter pylori, a pathogen that was seen in the distant era of the nineteenth century but without being recognized as such. It took 100 years to later discover the pathogenesis and the cancer that this bacterium can cause. Since it was discovered, until today, there has been a continuous search for the understanding of its pathogenetic mechanisms, and the therapeutic approach is continuously updated. Methods: We investigated how diagnosis and therapy were dealt with in the past and how researchers sought to understand, exactly, the pathogenetic biomolecular mechanisms of H. pylori, from the genesis of the infection to the current knowledge, with an analysis of carcinogenic mechanisms in the stomach. We have examined the scientific evolution of the knowledge of the disease over these 40 years in the gastroenterological and pharmacological fields. This was possible through a search in the databases of Medline, the WHO website, the Centers for Disease Control and Prevention (CDC) website, PubMed, and Web of Science to analyze the earlier and the latest data regarding H. pylori. Results: With the scientific discoveries over time, thanks to an increasing number of progressions in scientific research in the analysis of the gastric mucosa, the role of Helicobacter pylori in peptic ulcer, carcinogenesis, and in some forms of gastric lymphoma was revealed. Furthermore, over the years, the biomolecular mechanism involvement in some diseases has also been noted (such as cardiovascular ones), which could affect patients positive for H. pylori. Conclusions: Thanks to scientific and technological advances, the role of the bacterium H. pylori in carcinogenesis has been discovered and demonstrated, and new prospective research is currently attempting to investigate the role of other factors in the stomach and other organs. Cancer from H. pylori infection had a high incidence rate compared to various types of cancer, but in recent years, it is improving thanks to the techniques developed in the detection of the bacterium and the evolution of therapies. Thus, although it has become an increasingly treatable disease, there is still continuous ongoing research in the field of treatment for resistance and pharma compliance. Furthermore, in this field, probiotic therapy is considered a valid adjuvant.

The Binary Classification of Protein Kinases

In an earlier publication a binary model for chronic diseases classification has been proposed. According to the model, chronic diseases were classified as “high Treg” or “low Treg” diseases, depending on whether the immune response is anti- or pro-inflammatory and assuming that regulatory T cells are major determinants of the response. It turned out that most cancers are “high Treg” diseases, while autoimmune diseases are “low Treg”. This paper proposes a molecular cause for this binary response. The mechanism proposed depends on the effect of protein kinases on the immune system. Thus, protein kinases are classified as anti- or pro-inflammatory kinases depending on whether they drive “high Treg” or “low Treg” diseases. Observations reported in the earlier publication can be described in terms of anti-inflammatory kinase (AIK) or pro-inflammatory kinase (PIK) activity. Analysis of literature data reveals that the two classes of kinases display distinctive properties relating to their interactions with pathogens and environmental factors. Pathogens that promote Treg activity (“high Treg” pathogens) activate AIKs, while pathogens that suppress Treg activity (“low Treg” pathogens) activate PIKs. Diseases driven by AIKs are associated with “high Treg” pathogens while those diseases driven by PIKs are associated with “low Treg” pathogens. By promoting the activity of AIKs, alcohol consumption increases the risk of “high Treg” cancers but decreases the risk of some “low Treg” autoimmune diseases. JAK1 gain-of-function mutations are observed at high frequencies in autoimmune diseases while JAK1 loss-of-function mutations are observed at high frequencies in cancers with high tumor-infiltrating Tregs. It should also be noted that the corresponding two classes of protein kinase inhibitors are mutually exclusive in terms of their approved therapeutic indications. There is no protein kinase inhibitor that is approved for the treatment of both autoimmune diseases and “high Treg” cancers. Although there are exceptions to the conclusions presented above, these conclusions are supported by the great bulk of published data. It therefore seems that the binary division of protein kinases is a useful tool for elucidating (at the molecular level) many distinctive properties of cancers and autoimmune diseases.

A systematic review and meta-analysis for association of Helicobacter pylori colonization and celiac disease

BACKGROUND AND OBJECTIVES

Based on some previous observational studies, there is a theory that suggests a potential relationship between Helicobacter pylori (H. pylori) colonization and celiac disease (CeD); however, the type of this relationship is still controversial. Therefore, we aimed to conduct a systematic review and meta-analysis to explore all related primary studies to find any possible association between CeD and human H. pylori colonization.

DATA SOURCES

Studies were systematically searched and collected from four databases and different types of gray literature to cover all available evidence. After screening, the quality and risk of bias assessment of the selected articles were evaluated.

SYNTHESIS METHODS

Meta-analysis calculated pooled odds ratio (OR) on the extracted data. Furthermore, heterogeneity, sensitivity, subgroups, and publication bias analyses were assessed.

RESULTS

Twenty-six studies were included in this systematic review, with a total of 6001 cases and 135512 control people. The results of meta-analysis on 26 studies showed a significant and negative association between H. pylori colonization and CeD (pooled OR = 0.56; 95% CI = 0.45-0.70; P < 0.001), with no publication bias (P = 0.825). The L'Abbé plots also showed a trend of having more H. pylori colonization in the control group. Among subgroups, ORs were notably different only when the data were stratified by continents or risk of bias; however, subgroup analysis could not determine the source of heterogeneity.

CONCLUSIONS

According to the meta-analysis, this negative association might imply a mild protective role of H. pylori against celiac disease. Although this negative association is not strong, it is statistically significant and should be further considered. Further investigations in both molecular and clinic fields with proper methodology and more detailed information are needed to discover more evidence and underlying mechanisms to clear the interactive aspects of H. pylori colonization in CeD patients.

SYSTEMATIC REVIEW REGISTRATION NUMBER (PROSPERO)

CRD42020167730 https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=167730.

Effects of chlorpyrifos exposure on liver inflammation and intestinal flora structure in mice

Chlorpyrifos (CPF) is an organophosphate insecticide commonly used to treat fruit and vegetable crops. CPF can cause severe adverse effects on body organs including the liver and central nervous system. This study investigated the CPF-induced inflammation in mice and explored the role of intestinal flora changes in liver inflammation. Adult C57BL/6 male mice were exposed to a CPF of 0.01-, 0.1-, 1- and 10-mg/kg bodyweight for 12 weeks. The mice in experimental group given CPF solution dissolved in corn oil vehicle by gavage, was administered by intraoral gavage for 5 days per week for 12 weeks. Histopathological examination and inflammatory factor detection were performed on mice liver tissue. Faeces were used for 16S ribosomal RNA high-throughput sequencing to explore the impact of CPF on intestinal flora structure and diversity. The results showed that 1- and 10-mg/kg CPF caused different degrees of liver focal inflammation. The structure of intestinal flora changed significantly in mice including the decreased beneficial bacteria (Akkermansia, Prevotella and Butyricimonas) and increased pathogenic bacteria (Helicobacter and Desulfovibrio). Meanwhile, the results of Q-RT-PCR showed that there was more total bacterial DNA in the liver tissue of the mice treated with 10-mg/kg groups. In conclusion, the imbalance of intestinal flora, the decreased abundance of beneficial bacteria and the increased abundance of pathogenic bacteria, as well as the increase of total bacterial DNA in the liver tissues, maybe associated with the liver focal inflammation induced by CPF.

Helicobacter pylori and Upper Endoscopy in Systemic Sclerosis: A Cross-sectional Study in the Real World

BACKGROUND/AIMS

A role for Helicobacter pylori in triggering systemic sclerosis (SSc) has been proposed, but data are conflicting. In previous studies, infection has been generally searched for by using serology. We designed this study to assess H. pylori prevalence in SSc patients with histology of gastric mucosa, considered the criterion standard for infection diagnosis.

METHODS

This cross-sectional study enrolled 30 SSc patients who complained of upper gastrointestinal symptoms. All underwent upper endoscopy with gastric biopsies. Endoscopic alterations were recorded, and gastric mucosa biopsies were used for both histological examination and searching for H. pylori. The role for proton-pump inhibitor (PPI) therapy was considered. Fisher exact test was used for statistical analysis.

RESULTS

Data of 28 SSc patients were available, 14 with ongoing PPI therapy. Helicobacter pylori infection at histology was detected in 14.3% patients, and it equally occurred in patients with or without PPI therapy. Erosive esophagitis/Barrett esophagus was detected in 26.6% of cases. Among patients with PPI therapy, 30% received half dose only. The prevalence of intestinal metaplasia was low (14.3%). Endoscopic esophageal alterations were significantly more frequent in those patients showing anti-Scl70 antibody positivity.

CONCLUSIONS

This study showed that prevalence of H. pylori is very low in SSc patients, so that it seems not having a role in triggering SSc. Management of gastroesophageal diseases in SSc patients needs to be improved, and looking to the autoimmune profile may be of help. Thus, collaboration between rheumatologist and gastroenterologist is highly recommended.

H. pylori is related to NAFLD but only in female: A Cross-sectional Study

Background: Recently, an increasing number of studies have focused on the extragastrointestinal effects of Helicobacter pylori (H. pylori), including metabolic syndrome, fatty liver, and rheumatic and skin diseases. Nonalcoholic fatty liver disease (NAFLD) is a common chronic disease worldwide that conveys a heavy economic burden on patients and society. The aim of this study was to investigate the relationship between H. pylori and NAFLD and to identify potential influencing factors. Methods: We conducted a cross-sectional study of individuals who had undergone regular physical examinations at the Beijing Shijitan Hospital Health Examination Center from July to October 2018. We evaluated the associations between NAFLD and NAFLD with H. pylori infection and related serum markers using multiple linear regression and logistic regression. Results: There were significant relationships between H. pylori infection status and NAFLD in females (P=0.034) but not in males (P=0.795) according to Fisher's exact test. The association persisted after further adjustment for metabolic variables, gastrin factors, and liver enzymes. Waist-to-Hip Ratio, Body Mass Index, triglycerides, High-density lipoprotein cholesterol, glucose, uric acid, alkaline phosphatase, and Alanine aminotransferase are related to NAFLD after adjusting for age or interaction between biochemical indexes. Conclusion: H. pylori infection is related to NAFLD in female patients. The relationship between H. pylori and NAFLD may be mediated by markers of lipid metabolism and glycometabolism.

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.

Psychedelics as a novel approach to treating autoimmune conditions

With a rise in the incidence of autoimmune diseases (AiD), health care providers continue to seek out more efficacious treatment approaches for the AiD patient population. Classic serotonergic psychedelics have recently been gaining public and professional interest as novel interventions to a number of mental health afflictions. Psychedelics have also been shown to be able to modulate immune functions, however, while there has been great interest to researching into their psychotherapeutic applications, there has so far been very little exploration into the potential to treat inflammatory and immune-related diseases with these compounds. A handful of studies from a variety of fields suggest that psychedelics do indeed have effects in the body that may attenuate the outcome of AiD. This literature review explores existing evidence that psychedelic compounds may offer a potential novel application in the treatment of pathologies related to autoimmunity. We propose that psychedelics hold the potential to attenuate or even resolve autoimmunity by targeting psychosomatic origins, maladaptive chronic stress responses, inflammatory pathways, immune modulation and enteric microbiome populations.

Review: Extragastric diseases and Helicobacter pylori

The involvement of Helicobacter pylori infection in many extra-gastroduodenal manifestations remains a fascinating field of investigation. However, for several of these supposed associations, the potential pathogenic mechanism remains unclear. The present review highlights the main associations of H pylori with extra-gastroduodenal manifestations reported during the last year. We searched for the most relevant studies on this topic, published between April 2019 and March 2020, identified using the term "Helicobacter" in the MEDLINE/Pubmed database. Consistent data emerged from studies investigating metabolic syndrome and ischaemic cardiovascular diseases. Other reported fields of investigation were hepatology, especially focused on non-alcoholic steatohepatitis, neurology, including Parkinson's disease and Alzheimer's disease, as well as dermatology. Inflammatory bowel disease (IBD), that comprises Crohn's disease and ulcerative colitis, may originate from a dysregulation of the host's immune response to commensal bacteria in individuals with genetic predisposition. The reduction of biodiversity and other specific imbalances in the faecal microbiome composition of IBD patients compared to that of healthy controls support this hypothesis. In this context, an inverse correlation between H pylori infection and IBD prevalence has been confirmed. Similar results were found in patients with kidney diseases and allergic manifestations. There are indications of the possible involvement of H pylori infection in metabolic syndrome and ischaemic cardiovascular diseases. However, due to a series of factors linked to study designs and the multifactorial pathogenesis of some diseases, further studies are needed.

H. Pylori is related to osteoporosis but only in premenopausal female: a cross-sectional study

Background

Recently, an increasing number of studies have focused on the extra-gastrointestinal effects of Helicobacter pylori (H. pylori), including metabolic syndrome, fatty liver, and rheumatic and skin diseases. Osteoporosis is an asymptomatic disease that can eventually lead to fractures and has a significant impact on the quality of life of elderly individuals. Sex is an influential factor that plays a crucial role in the development of osteoporosis. The aim of this study was to investigate the relationship between H. pylori infection and osteoporosis and to identify potential influencing factors.

Methods

We conducted a cross-sectional study of individuals older than 50 years old, who had undergone regular physical examinations at the Beijing Shijitan Hospital Health Examination Center from July to October 2018. We evaluated the associations of osteopenia and osteoporosis with H. pylori infection and related serum markers by using multiple linear regression and logistic regression. Then, we analysed the correlation between sex and potential serum biomarkers.

Results

There were significant relationships between H. pylori infection status and bone density in premenopausal females but not in males (P = 0.381) according to Fisher’s exact test. In females, H. pylori positivity (OR = 0.132, P = 0.023), Body Mass Index (BMI) (OR = 28.163, P = 0.021), and homocysteine (HCY) (OR = 17.218, P = 0.045) were associated with osteoporosis. Calcium had a trend but no statistically significant (OR = 0.060, P = 0.076) relationship with osteoporosis. Furthermore, the waist-to-hip ratio (OR = 5.783, P = 0.029), BMI (OR = 0.152, P = 0.014) and triglyceride levels (OR = 0.201, P = 0.036) were significantly different by sex, after adjusting for age as a confounder.

Conclusion

H. pylori positivity, BMI and HCY are associated with osteoporosis in premenopausal females. Chronic inflammation may be involved in the relationship between H. pylori and osteoporosis.

Microorganisms associated to thyroid autoimmunity

Autoimmune thyroid diseases are a group of diseases characterized by a dysfunction of the immune system concerning the thyroid gland, associated with hypothyroidism or hyperthyroidism. The thyroid gland autoimmunity has been recognized as multifactorial. It has been reported that microorganisms may play a role on the pathogenesis of Hashimoto's thyroiditis and Graves´ disease. These could explain the high incidence of the autoimmune thyroid diseases. Helicobacter Pylori (H. pylori) and Hepatitis C virus (HCV) are the microorganisms in which the association with autoimmune thyroid diseases is clearer. The pathophysiologic mechanisms are still not well defined. For H. pylori, molecular mimicry has been the most accepted mechanism. It has been proposed Hepatitis C virus as the trigger of the thyroid autoimmunity by exacerbating the production of thyroid auto-antibodies, while some mention that the real factor that triggers the thyroid autoimmunity is the treatment with Interferon alpha (IFN-alpha) by upregulating MHC class I and inducing ligation of CD40+ cells to thyrocytes. Other microorganisms such as Toxoplasma gondii, Human Immunodeficiency virus, Herpes virus and others have reported information about their association with thyroid autoimmune diseases There are no proposals on how these last microorganisms induce thyroid autoimmunity. There is still a lack of evidence on this topic. Further research must be done to determine the interaction of these microorganisms and the best way to manage these patients.

Role of Helicobacters in Neuropsychiatric Disease: A Systematic Review in Idiopathic Parkinsonism

Interest in an aetiopathogenic role for Helicobacter in neuropsychiatric diseases started with idiopathic parkinsonism (IP), where the cardinal signs can be assessed objectively. This systematic review, using an EMBASE database search, addresses Oxford Centre for Evidence-Based Medicine based questions on the inter-relationship of Helicobacter and IP, the benefits of eradicating Helicobacter in IP and the outcome of not treating. The search strategy was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines: 21 of 204 articles met the inclusion criteria. The results show that the assumption that any benefit of Helicobacter eradication results from improved levodopa bioavailability is unjustified. The inter-relationship between Helicobacter and IP is well-established. H. pylori virulence markers (associated with autoimmunity and immune tolerance) influence the risk, severity and progression of IP. The birth cohort effect for virulence marker antibodies, seen in controls, is obliterated in IP, suggesting causality. Successful H. pylori eradication in IP is disease-modifying (even in anti-parkinsonian treatment-naïve patients) but not preventive. Hypokinesia regresses with eradication and overall motor severity lessens. Eradication may influence gastrointestinal microbiota adversely, unlocking the next stage in the natural history, the development of rigidity. Failed eradication worsens hypokinesia, as does the presence/persistence of H. pylori at molecular level only. Adequate prognostic assessment of the consequences of not treating Helicobacter, for IP, is prevented by a short follow-up. We conclude that Helicobacter is a pathophysiological driver of IP.

Synthesis of Interleukin-10 in Patients with Ulcerative Colitis and Helicobacter pylori Infection

METHODS

Detection of H. pylori infection was performed by a 13C-urea breath test in 31 patients with UC. In each patient, a serum sample was drawn to measure IL-10 by the ELISA technique. Based on the primary breath test result, two groups were formed and serum IL-10 was measured.

RESULTS

Serological IL-10 levels in patients with UC and negative 13C-urea breath test was 10.28 pg/ml whereas in patients with UC and positive 13C-urea breath test was 5.5 pg/ml (P = 0.035). IL-10 levels were higher in the inflammatory endoscopic and histological active groups which tested positive in the 13C-urea breath tests for H. pylori (P < 0.05).

CONCLUSIONS

The role of IL-10 secretion in patients with UC in determining the clinicopathological outcome of infection merits further study. This study suggests an association between serum IL-10 and disease severity in patients with UC and HP infection.

Relationship between Helicobacter pylori infection and psoriasis: a nationwide population-based longitudinal cohort study

BACKGROUND

In the current literature, studies assessing the role of Helicobacter pylori (HP) infection in psoriasis have reported conflicting data. Therefore, we investigated the association between HP infection and psoriasis using a nationwide population-based longitudinal cohort study.

METHODS

We identified 41,539 patients with HP infection and 83,078 matched controls between 2000 and 2013 from the Longitudinal Health Insurance Research Database of the National Health Insurance Research Database in Taiwan. Propensity score analysis was used to match age, sex, comorbidities, and medical visits at a ratio of 1:2. Multiple Cox regression analysis was used to estimate the adjusted hazard ratio of psoriasis. Furthermore, sensitivity tests and a stratified analysis were conducted.

RESULTS

The incidence rates of psoriasis did not differ significantly between the HP and control cohorts (4.58 vs 4.20 per 100,000 person-months, crude relative risk: 1.092, 95% confidence interval: 0.917-1.302). After multivariate adjustment, no significant difference in psoriasis risk was observed in patients with HP infection (adjusted hazard ratio: 1.081, 95% confidence interval: 0.907-1.288). Risk of psoriasis was significantly higher in men and the elderly, and in those with diabetes, hyperlipidemia, chronic obstructive pulmonary disease, or tuberculosis. Stratified analysis also confirmed that HP infection was not correlated with an increased risk of psoriasis based on follow-up duration, sex, and age.

CONCLUSION

This retrospective population-based longitudinal cohort study, conducted in Taiwan, found no association between HP infection and risk of psoriasis. Further research may be warranted.

Effect of early eradication therapy on systemic lupus erythematosus risk in patients with Helicobacter pylori infection: a nationwide population-based cohort study

Background

This study aimed to investigate whether early eradication therapy influences systemic lupus erythematosus (SLE) risk in patients with Helicobacter pylori (HP) infection.

Methods

We identified 41,653 patients with HP infection in Taiwan from 2000 to 2013. The patient population was divided into early (within three months) and late (after three months) eradication cohorts. age, sex, co-morbidities and medical visits were matched at a 1:1 ratio. Multiple Cox regression, sensitivity analysis and stratified analysis were used to estimate SLE adjusted hazard ratios (aHR).

Results

The relative risk of SLE was 0.75 (95% confidence interval 0.43–1.31) in the early eradication cohort. After multivariate adjustment, the SLE risk was non-significantly lower in the early eradication cohort than in the late eradication cohort (aHR = 0.74, 95% CI 0.42–1.29). Stratified analysis revealed that early eradication could significantly reduce SLE risk during the three-year follow-up period (aHR = 0.16, 95% CI 0.05–0.53, p for interaction = 0.0013). Compared to eradication within three months of diagnosis, eradication within 3–36 months and >36 months corresponded with SLE aHRs of 4.78 (95% CI 1.19–19.20) and 7.66 (95% CI 2.17–27.05), respectively, when the follow-up period was less than three years.

Conclusion

Early HP eradication could significantly reduce SLE risk, especially in the first three-year follow-up.

The dark side of Sjögren's syndrome: the possible pathogenic role of infections

PURPOSE OF REVIEW

To highlight recent findings on pathogenic mechanisms and clinical associations which characterize the role of infectious agents as triggers for Sjögren's syndrome development.

RECENT FINDINGS

Several candidate infectious agents have been identified to induce the autoimmune and inflammatory pathways leading to Sjögren's syndrome clinical appearance in the setting of a genetic background. This is reinforced by the demonstration that Sjögren's syndrome patients are characterized by higher prevalence of seropositivity to virus and bacterial agents in comparison with general population. Moreover, these agents may infect salivary gland epithelial cells. Stronger evidence confirmed the role of some viruses, like Epstein-Barr, as triggers of the disease and different mechanisms have been demonstrated to interplay. Recent experimental and clinical studies supported the adjunctive role of an altered buccal and intestinal microbial composition and chronic inflammatory response to Helicobacter pylori in disease induction. Finally, latent viral infections and immune system chronic stimulation induced by persistent infections may participate in disease lymphoproliferative evolution.

SUMMARY

Different viral and bacterial agents have been identified as triggers in Sjögren's syndrome induction and contributors to the chronic immune system stimulation underlying lymphoproliferative complication. Deeper knowledge of involved microbial agents and pathogenic mechanisms linking Sjögren's syndrome and infections may help the identification of preventive therapeutic strategy.

Association between Helicobacter pylori infection and Guillain-Barré Syndrome: A meta-analysis

BACKGROUND

Helicobacter pylori (H pylori) is a Gram-negative bacterium, considered to trigger autoimmune gastrointestinal disorders. This pathogen has also been linked to the autoimmune sequelae in extra-gastrointestinal diseases and peripheral neuropathies. Guillain-Barré syndrome (GBS) is a serious autoimmune demyelinating disorder of peripheral nerves, usually with a post-infectious onset. About 30% of cases of GBS attributed to by Campylobacter jejuni, so, H pylori, could be also involved. Growing evidence suggests the likely involvement of H pylori infection in the development of GBS. The aim of the current study was to therefore estimate the prevalence of H pylori antibodies in GBS.

METHODS

A search of the literature was performed, using the PUBMED database, until December 2018. Data were extracted from six case-control studies, and a stratification analysis was conducted according to cerebrospinal fluid (CSF) or serum detection material.

RESULTS

Among 29 records found, 6 studies met in the inclusion criteria for the meta-analysis. In the CSF subgroup, 105 participants were involved (40 GBS patients and 65 controls), while the serum subgroup included 325 participants (152 GBS and 173 controls). Data were combined using a fixed-effects model. Anti-H pylori IgG were significantly more prevalent in GBS patients compared to controls, in both CSF (95% CI: 9.66-186.56, OR: 42.45, Pz < .00001) and serum (95% CI: 1.30-4.11, OR: 2.31, Pz: .004) subgroups.

CONCLUSION

The present meta-analysis showed a strong association between GBS and the presence of H pylori antibodies, especially in CSF, thereby suggesting a role of H pylori infection in the pathophysiology of GBS.

Helicobacter pylori infection in psoriatic patients during biological therapy

BACKGROUND

Psoriasis is a relapsing inflammatory disease exacerbated by many triggers. Helicobacter pylori (H. pylori) is a Gram-negative bacterium causing the liberation of many cytokines and having a role in systemic inflammation. We assessed over a period of 12 months the presence of H. pylori in psoriatic patients undergoing biologic therapy and how PASI improved after its eradication.

METHODS

We performed an interventional, prospective, cohort, exploratory and mono-centric study in patients affected by moderate-severe psoriasis during biological therapy to assess the correlation between psoriasis (moderate to severe forms), and H. pylori infection. We also checked if the bacterial eradication could improve the severity of psoriasis throughout the variation of PASI over a 12-month period.

RESULTS

The prevalence of H. pylori was 35%. The average of PASI improved in H. pylori positive patients after the eradication (confidence interval: 33-44; P=0.023). H. pylori positive patients were more likely to have psoriatic arthropathy (P=0.049). Gastrointestinal symptoms (such as epigastric pain, postprandial heaviness, pyrosis) were found in only 31.3% of H. pylori positive patients.

CONCLUSIONS

Since the H. pylori infection is often asymptomatic, it can be useful to perform the 13C-Urea breath test, and to eradicate it before to start the psoriasis therapy in order to decrease the level of inflammation.

Increased Risk of Systemic Lupus Erythematosus in Patients With Helicobacter pylori Infection: A Nationwide Population-Based Cohort Study

Helicobacter pylori (HP) infection is associated with systemic lupus erythematosus (SLE), but the related results have been controversial. Therefore, this study investigated the association between HP infection and SLE by using a nationwide longitudinal population-based cohort. We identified 41,651 patients with HP infection and 83,302 matched controls between 2000 and 2013 from the Longitudinal Health Insurance Research Database of the National Taiwan Insurance Research Database. Age, gender, comorbidities, and medical visits were matched at a 1:2 ratio by using propensity score analysis. The adjusted hazard ratio (aHR) of SLE was calculated by multiple Cox regression. Furthermore, sensitivity test and stratified analysis were performed. The SLE incidence rate was 1.17 [95% confidence interval (CI): 0.89–1.54] per 100,000 person-months in the HP cohort, and the hazard ratio was 1.63 (95% CI: 1.12–2.37) in comparison with the propensity score-matched control cohort. After multivariate adjustment, patients with HP infection had a significantly high overall aHR (1.58; 95% CI: 1.08–2.30) of SLE. Stratified analysis revealed the aHR of 8.23 (95% CI: 1.77–38.32) in patients <30 years old, and the p for interaction between age and HP infection was 0.039. For age–sex subgroup analysis, the highest aHR was 12.74 (95% CI: 1.55–104.59) in young (aged <30 years) female patients with HP infection. HP infection is associated with a 1.63-fold increased SLE risk, particularly with female patients aged <30 years. Future research is required to elucidate the underlying mechanism of this association.

Immune-mediated genesis of multiple sclerosis

Multiple sclerosis (MS) is widely acknowledged to be an autoimmune disease affecting the neuronal myelin structure of the CNS. Autoantigens recognized as the target of this autoimmune process are: myelin basal protein, anti-proteolipid protein, antimyelin-associated glycoprotein and antimyelin-based oligodendrocytic basic protein. Ample evidence supports the idea of a dysregulation of immunological tolerance towards self-antigens of neuronal myelin structure triggered by one or more viral or bacterial microbial agents in predisposed HLA gene subjects. Genetic predisposition to MS has been highlighted by numerous studies associating the disease to specific HLA haplotypes. Moreover, a wide range of evidence supports the fact that MS may be consequence of one or more viral or bacterial infections such as measles virus, EBV, HHV6, HZV, Chlamydia pneumoniae, Helicobacter Pylori, and other microbial agents. Microbiota elements also seems to have a role on the determinism of the disease as a pathogenic or protective factor. The autoimmune pathogenetic process could arise when a molecular mimicry between a foreign microbial antigen and an auto-antigen occurs in an HLA gene subject competent for that particular antigen. The antigen-presenting cells in this case would induce the activation of a specific Th clone causing a cross-reaction between a foreign antigen and an autoantigen resulting in an autoimmune response.

•

A multifactorial ethiopathogenetic model based on immunomediation is a reliable hypothesis for multiple sclerosis.

•

Evidence found in the scientific literature makes it possible to reconstruct this etiopathogenetic hypothesis for MS.

•

HLA gene predisposition, correlation with infections, molecular mimicry and other immunological data are reported.

The Binary Classification Of Chronic Diseases

Acute diseases start with an insult and end when insult disappears. If the trauma induces an immune reaction (which happens in most cases), this reaction must be terminated with some type of resolution mechanism, when the cause of the trauma ceases. Chronicity develops if insult is permanent or if the resolution mechanism is defective. Another way to reach disease chronicity is a positive feedback loop, whereby the immune reaction activates an internal, insult-like reaction. A distinction between chronic states characterized by a persistent, low suppressive effect and those characterized by a persistent, high suppressive effect of regulatory T cells (Treg), is proposed. This two-class division represents two ways to reach chronicity: (a) by maintaining inflammatory reaction long after insult disappears ("low Treg"), or (b) by suppressing inflammatory reaction prior to the disappearance of insult ("high Treg"). This two-class division may explain the strong association between certain pathogens and cancer, on one hand, and between several other pathogens and autoimmunity, on the other hand. The weak association between autoimmune diseases and HIV infection and the relatively weak association between autoimmune diseases and cancer may be elucidated as well. In addition, the model rationalizes why immune-modulating drugs, which are effective in cancer, are also effective in "high Treg" viral infections, while corticosteroids, which are generally effective in autoimmune diseases, are also effective in other "low Treg" diseases (such as asthma, atopic dermatitis, and "low Treg" infections) but are not effective in solid malignancies and "high Treg" infections. Moreover, the model expounds why certain bacteria inhibit tumor growth and why these very bacteria induce autoimmune diseases.

Gastric cancer in autoimmune gastritis: A case-control study from the German centers of the staR project on gastric cancer research

Objectives

Patients with autoimmune gastritis (AIG) are reported to have an increased risk of developing gastric cancer (GC). In this study, we assess the characteristics and outcomes of GC patients with AIG in a multicenter case-control study.

Methods

Between April 2013 and May 2017, patients with GC, including cancers of the esophagogastric junction (EGJ) Siewert type II and III, were recruited. Patients with histological characteristics of AIG were identified and matched in a 1:2 fashion for age and gender to GC patients with no AIG. Presenting symptoms were documented using a self-administered questionnaire.

Results

Histological assessment of gastric mucosa was available for 572/759 GC patients. Overall, 28 (4.9%) of GC patients had AIG (67 ± 9 years, female-to-male ratio 1.3:1). In patients with AIG, GC was more likely to be localized in the proximal (i.e. EGJ, fundus, corpus) stomach (odds ratio (OR) 2.7, 95% confidence interval (CI) 1.0–7.1). In GC patients with AIG, pernicious anemia was the leading clinical sign (OR 22.0, 95% CI 2.6–187.2), and the most common indication for esophagogastroduodenoscopy (OR 29.0, 95% CI 7.2–116.4). GC patients with AIG were more likely to present without distant metastases (OR 6.2, 95% CI 1.3–28.8) and to be treated with curative intention (OR 3.0, 95% CI 1.0–9.0). The five-year survival rates with 95% CI in GC patients with and with no AIG were 84.7% (83.8–85.6) and 53.5% (50.9–56.1), respectively (OR 0.25, 95% CI 0.08–0.75, p = 0.001).

Conclusions

Pernicious anemia leads to earlier diagnosis of GC in AIG patients and contributes significantly to a better clinical outcome.

Environmental Triggers of Autoreactive Responses: Induction of Antiphospholipid Antibody Formation

Antiphospholipid antibodies (aPLs) comprise a diverse family of autoantibodies targeted against proteins with the affinity toward negatively charged phospholipids or protein-phospholipid complexes. Their clinical significance, including prothrombotic potential of anti-cardiolipin antibodies (aCLs), anti-β2-glycoprotein I antibodies (aβ2-GPIs), and lupus anti-coagulant (LA), is well-established. However, the ontogeny of these pathogenic aPLs remains less clear. While transient appearance of aPLs could be induced by various environmental factors, in genetically predisposed individuals these factors may eventually lead to the development of the antiphospholipid syndrome (APS). Since the first description of APS, it has been found that a wide variety of microbial and viral agents influence aPLs production and contribute to clinical manifestations of APS. Many theories attempted to explain the pathogenic potential of different environmental factors as well as a phenomenon termed molecular mimicry between β2-GPI molecule and infection-relevant structures. In this review, we summarize and critically assess the pathogenic and non-pathogenic formation of aPLs and its contribution to the development of APS.