Higher serum levels of rheumatoid factor and anti-nuclear antibodies in helicobacter pylori-infected peptic ulcer patients

SARS-CoV-2 infection relaxes peripheral B cell tolerance

Severe SARS-CoV-2 infection is associated with strong inflammation and autoantibody production against diverse self-antigens, suggesting a system-wide defect in B cell tolerance. BND cells are a B cell subset in healthy individuals harboring autoreactive but anergic B lymphocytes. In vitro evidence suggests inflammatory stimuli can breach peripheral B cell tolerance in this subset. We asked whether SARS-CoV-2-associated inflammation impairs BND cell peripheral tolerance. To address this, PBMCs and plasma were collected from healthy controls, individuals immunized against SARS-CoV-2, or subjects with convalescent or severe SARS-CoV-2 infection. We demonstrate that BND cells from severely infected individuals are significantly activated, display reduced inhibitory receptor expression, and restored BCR signaling, indicative of a breach in anergy during viral infection, supported by increased levels of autoreactive antibodies. The phenotypic and functional BND cell alterations significantly correlate with increased inflammation in severe SARS-CoV-2 infection. Thus, autoreactive BND cells are released from peripheral tolerance with SARS-CoV-2 infection, likely as a consequence of robust systemic inflammation.

Relationship between Helicobacter pylori cytotoxin-associated gene A protein with clinical outcomes in patients with rheumatoid arthritis

INTRODUCTION

The Helicobacter pylori(H. pylori) infection leads to intensification of symptoms and calenture of autoimmune diseases. This study aimed to evaluate the relationship between H. pylori infection and clinical outcomes in rheumatoid arthritis (RA) patients.

METHODOLOGY

This study was performed on 100 RA patients. Blood samples were collected for measuring Anti-H. pylori IgG antibodies and cytotoxin-associated gene A (CagA) protein. Fresh fecal samples were also collected and the fecal H. pylori antigen was extracted. Clinical condition as well as severity and type of RA symptoms in both groups of H. pylori positive and H. pylori negative were also compared.

RESULTS

Serum levels of rheumatoid factor (RF), ESR, CRP, anti-cyclic citrullinated peptide (Anti-CCP), and anti-mutated citrullinated vimentin (Anti-MCV) were significantly higher in H. pylori positive patients than in H. pylori negative patients (P < 0.05). Serum RF, ESR, CRP and Anti-MCV levels were significantly higher in CagA positive patients than in CagA negative patients (P < 0.05). There were no significant differences in DAS-28 scores between H. pylori positive and H. pylori negative patients (P = 0.064) as well as between patients with positive and negative fecal H. pylori antigen (P = 0.237). However, DAS-28 score was significantly higher in CagA positive patients than in CagA negative patients (P < 0.001). Furthermore, mean VAS score was significantly higher in H. pylori positive patients (P = 0.031) and CagA positive patients (P = 0.004); however, there were no significant differences in VAS scores between patients with positive and negative fecal H. pylori antigen (P = 0.310).

CONCLUSION

Follow-up and examination of RA patients in terms of infection with serum and fecal H. pylori organism and CagA seems necessary that will contribute to better and further control and treatment of the patients.

Diminished circulating concentration of interleukin-35 in Helicobacter pylori-infected patients with peptic ulcer: Its association with FOXP3 gene polymorphism, bacterial virulence factor CagA, and gender of patients

BACKGROUND

IL-35 modulates immune and inflammatory responses during infections. Here, we investigated IL-35 levels and a single nucleotide polymorphism, rs3761548, in FOXP3 gene in Helicobacter pylori-infected patients with peptic ulcer (PU), to clarify possible associations.

MATERIALS AND METHODS

This study includes 100 H. pylori-infected PU patients, 100 H. pylori-infected asymptomatic subjects (AS), and 100 noninfected healthy subjects (NHSs). Serum IL-35 levels and the genotyping were determined using ELISA and RFLP-PCR methods, respectively.

RESULTS

In PU patients, the IL-35 levels were lower than AS and NHS groups (P < .001). The IL-35 levels in CagA⁺ H. pylori-infected participants from PU and AS groups were lower than individuals infected with CagA^- strains (P < .02 and P < .04, respectively). Women had higher IL-35 levels than men among PU, AS, and NHS groups (P < .0001). In PU patients, AA genotype and A allele at rs3761548 were more frequent than total healthy subjects (AS + NHS groups) and associated with an increased PU risk (AA genotype: OR = 5.51, P < .0001; A allele: OR = 3.857, P < .002). In PU and AS groups, IL-35 levels were lower in subjects displaying AA genotype or A allele than subjects displaying CC genotype or C allele, respectively (P < .0001 and P < .03 for PU patients; P < .001 and P < .02 for AS group, respectively).

CONCLUSIONS

Decreased IL-35 levels could be involved in PU development in H. pylori-infected individuals. IL-35 levels are affected by CagA status of H. pylori, participants gender, and genetic variations at rs3761548. The AA genotype and A allele at rs3761548 could represent a risk factor for PU development.

T cell subsets play an important role in the determination of the clinical outcome of Helicobacter pylori infection

Helicobacter pylori (H. pylori) is one of the most prevalent human pathogen and a persistent infection with this bacterium causes common pathologies, such as gastritis or peptic ulcers, and also less common but more serious pathologies, such as gastric cancer or gastric mucosa-associated lymphoid tissue (MALT) lymphoma. The clinical outcome of gastrointestinal infection sustained by H. pylori is determined by the reciprocal interactions between virulence factors of the bacterium and host factors, including immune response genes. Although H. pylori induces a strong immune response, the bacterium is not eliminated. The eradication failure could be attributed to the bacterial capability to regulate helper T (Th) cell-related responses. H. pylori specific CD4⁺ T cells play a fundamental role in regulating host immunity and immunopathologic events. It has been documented that Th1, Th2, Th9, Th17, Th22 and T regulatory (Treg) cells, separately or in coordination with each other, can affect the outcome of the infection sustained by of H. pylori. Some studies indicated that both Th1 and Th17 cells may be protective or pathogenic, whereas Treg and Th2 cells perform anti-inflammatory impacts during H. pylori infection. This review gathers recent information regarding the association of the CD4⁺ T cells-mediated immunological responses and the clinical consequence of H. pylori infection.

Immunological tolerance as a barrier to protective HIV humoral immunity

HIV-1 infection typically eludes antibody control by our immune system and is not yet prevented by a vaccine. While many viral features contribute to this immune evasion, broadly neutralizing antibodies (bnAbs) against HIV-1 are often autoreactive and it has been suggested that immunological tolerance may restrict a neutralizing antibody response. Indeed, recent Ig knockin mouse studies have shown that bnAb-expressing B cells are largely censored by central tolerance in the bone marrow. However, the contribution of peripheral tolerance in limiting the HIV antibody response by anergic and potentially protective B cells is poorly understood. Studies using mouse models to elucidate how anergic B cells are regulated and can be recruited into HIV-specific neutralizing antibody responses may provide insight into the development of a protective HIV-1 vaccine.

Toll-like receptor 2: An important immunomodulatory molecule during Helicobacter pylori infection

Toll like receptors (TLRs) are an essential subset of pathogen recognition receptors (PRRs) which identify the microbial components and contribute in the regulation of innate and adaptive immune responses against the infectious agents. The TLRs, especially TLR2, TLR4, TLR5 and TLR9, participate in the induction of immune response against H. pylori. TLR2 is expressed on a number of immune and non-immune cells and recognizes a vast broad of microbial components due to its potential to form heterodimers with other TLRs, including TLR1, TLR6 and TLR10. A number of H. pylori-related molecules may contribute to TLR2-dependent responses, including HP-LPS, HP-HSP60 and HP-NAP. TLR2 plays a pivotal role in regulation of immune response to H. pylori through activation of NF-κB and induction of cytokine expression in epithelial cells, monocytes/macrophages, dendritic cells, neutrophils and B cells. The TLR2-related immune response that is induced by H. pylori-derived components may play an important role regarding the outcome of the infection toward bacterial elimination, persistence or pathological reactions. The immunomodulatory and immunoregulatory roles of TLR2 during H. pylori infection were considered in this review. TLR2 could be considered as an interesting therapeutic target for treatment of H. pylori-related diseases.

Helicobacter pylori and extragastric diseases

While Helicobacter pylori infection was initially revealed to be associated only with some gastroduodenal diseases, further studies have shown its possible role in several extragastric diseases. For idiopathic thrombocytopenic purpura, sideropenic anemia, and vitamin B12 deficiency, the diagnosis of H. pylori infection is recommended, and there are many other conditions such as cardiovascular, neurological, dermatological, and respiratory diseases in which H. pylori may possibly play a role. Interestingly, a potential role has also been described for GI neoplastic diseases, including colorectal and pancreatic cancer. Different mechanisms of action have been proposed, ranging from the induction of a low grade inflammatory state to the occurrence of molecular mimicry mechanisms. This review summarizes the results of the most relevant studies published on this topic over the last year.