Gastric Mucosa-associated Lymphoid Tissue Research Articles

Endoscopic submucosal dissection for protruding Helicobacter pylori-negative mucosa-associated lymphoid tissue lymphoma of the stomach: a case report

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas have various endoscopic appearances. We report a case of Helicobacter pylori-negative gastric MALT lymphoma with a protruding morphology similar to that of submucosal tumors. A 51-year-old man with a protruding tumor in the gastric cardia was referred to our hospital. Biopsy specimens showed no malignant epithelial tumors or lymphoid hyperplasia. Endoscopic submucosal dissection was performed and the patient was diagnosed with gastric MALT lymphoma. Lymphoma cells were present in the lamina propria mucosae and the submucosa under the non-atrophic fundic gland mucosa, with a feature of homogenous and monotonous growths, which was speculated to have resulted in a protruding morphology similar to that of submucosal tumors. Endoscopic submucosal dissection can be an alternative diagnostic option for gastric MALT lymphoma when the initial pathological diagnosis based on biopsy specimens is difficult.

MR-LINAC-Guided Adaptive Radiotherapy for Gastric MALT: Two Case Reports and a Literature Review

It is still very challenging to use conventional radiation therapy techniques to treat stomach tumors, although image-guided radiotherapy, mainly by kV X-ray imaging techniques, has become routine in the clinic. This is because the stomach is one of the most deformable organs, and thus it is vulnerable to respiratory motions, daily diet, and body position changes. In addition, X-ray radiographs and CT volumetric images have low contrast in soft tissues. In contrast, magnetic resonance imaging (MRI) techniques provide good contrast in images of soft tissues. The emerging MR-guided radiotherapy, based on the MR-LINAC system, may have the potential to solve the above difficulties due to its unique advantages. The real-time imaging feature and the high-contrast of soft tissues MR images provided by the MR-LINAC system have facilitated the therapeutic adaptive planning. Online learning capabilities could be used to optimize the automatic delineation of the target organ or tissue prior to each radiotherapy session. This could greatly improve the accuracy and efficiency of the target delineation in adaptive planning. In this clinical case report, we elaborated a workflow for the diagnosis and treatment of two patients with gastric mucosa-associated lymphoid tissue (MALT) lymphoma. One patient underwent MR-guided daily adaptive radiotherapy based on daily automated segmentation using the novel artificial intelligence (AI) technique for gastric delineation.

The Efficacy of Cancer Immunotherapies Is Compromised by Helicobacter pylori Infection.

Helicobacter pylori infects the gastric mucosa of a large number of humans. Although asymptomatic in the vast majority of cases, H pylori infection can lead to the development of peptic ulcers gastric adenocarcinoma and mucosa-associated lymphoid tissue (MALT) lymphoma. Using a variety of mechanisms, H pylori locally suppresses the function of the host immune system to establish chronic infection. Systemic immunomodulation has been observed in both clinical and pre-clinical studies, which have demonstrated that H pylori infection is associated with reduced incidence of inflammatory diseases, such as asthma and Crohn’s disease. The introduction of immunotherapies in the arsenal of anti-cancer drugs has revealed a new facet of H pylori-induced immune suppression. In this review, we will describe the intimate interactions between H pylori and its host, and formulate hypothtyeses describing the detrimental impact of H pylori infection on the efficacy of cancer immunotherapies.

Investigation of endoscopic findings in nine cases of Helicobacter suis-infected gastritis complicated by gastric mucosa-associated lymphoid tissue lymphoma.

We have previously reported that eradication therapy was more effective against Helicobacter pylori (Hp)-negative gastric mucosa-associated lymphoid tissue (MALT) lymphoma in non-Helicobacter pylori Helicobacter (NHPH)-positive cases than in NHPH-negative cases and that the infection status of NHPH could be a predictive marker for the efficacy of eradication therapy for H.pylori negative gastric MALT lymphoma. However, a diagnostic test for NHPH infection has not yet been clinically established. In this study, we investigated the endoscopic findings in cases of H.suis-infected gastritis associated with gastric MALT lymphoma reported at our institution. Participants were selected from cases of gastric MALT lymphoma who underwent esophagogastroduodenoscopy at Hiroshima University Hospital, who were negative for the API2-MALT1gene, and who received eradication therapy as a first-line treatment. We examined the endoscopic findings in nine cases from this group in which H.suis infection was confirmed by polymerase chain reaction. Endoscopic findings, such as cracked mucosa, spotty redness, nodular gastritis-like appearance, and white marbled appearance, which have been reported as characteristics of NHPH gastritis, were observed in multiple cases. The most common endoscopic findings in this study were cracked mucosa (7/9 cases), followed by spotty redness (6/9 cases), nodular gastritis-like appearance (5/9 cases), and white marbled appearance (2/9 cases). Our study may serve as a reference for re-evaluation of the diagnostic criteria for H.suis infection and indications for eradication therapy, particularly for cases of H.pylori negative gastric MALT lymphoma, where endoscopic findings such as those seen in this study were observed in the background mucosa.

Relationship between Helicobacter Pylori and colon cancer

BACKGROUND: Helicobacter pylori is a Gram-negative bacteria found in the gastric epithelia of around half of the world's population. Chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue, and stomach cancer are all known to be caused by this illness. Furthermore, there is evidence that bacteria are linked to a number of extragastric disorders. Since it was initially hypothesized that the link between extragastric illnesses and colon cancer. OBJECTIVE: The objective of this study was to obtain the correlation between colon cancer and H. pylori infection. METHODS: In this study, we tested blood samples were collected from the patients with colon cancer to assess the presence of anti-H. pylori infection antibodies in 10 patients with colorectal cancer and 10 with no specific pathologies as a control group. RESULTS: There was a statistically significant difference (P > 0.05) and a highly significant difference (P > 0.001) in H. pylori infection and colon cancer between patients and control, respectively. A significant correlation between H. pylori infection and colon cancer (P > 0.05) was noted. It was found to be a positive linear correlation with H. pylori infection (r = 0.436) and significant (P = 0.027). The study showed a significant correlation between age and H. pylori and colon cancer (P = 0.013 and P = 0.034, respectively). CONCLUSION: H. pylori infection is one of the risk factors that develop colon cancer. The old age correlates with increased colon cancer and H. pylori infection.

Effects ofHelicobacter pyloriinfection in gastrointestinal tract malignant diseases: From the oral cavity to rectum

Helicobacter pylori (H. pylori) has infected approximately fifty percent of humans for a long period of time. However, improvements in the public health environment have led to a decreased chance of H. pylori infection. However, a high infection rate is noted in populations with a high incidence rate of gastric cancer (GC). The worldwide fraction of GC attributable to H. pylori is greater than 85%, and a high H. pylori prevalence is noted in gastric mucosa-associated lymphoid tissue lymphoma patients. These results indicate that the majority of GC cases can be prevented if H. pylori infection is eliminated. Because H. pylori exhibits oral-oral or fecal-oral transmission, the relationship between this microorganism and other digestive tract malignant diseases has also attracted attention. This review article provides an overview of H. pylori and the condition of the whole gastrointestinal tract environment to further understand the correlation between the pathogen and the host, thus allowing improved realization of disease presentation.

Helicobacter pylori cagA status and gastric mucosa-associated lymphoid tissue lymphoma: a systematic review and meta-analysis

BackgroundRecent studies have investigated the role of Helicobacter pylori infection in the development of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. It is estimated that approximately 0.1% of people infected with H. pylori develop gastric MALT lymphoma. However, the role of the CagA antigen, the highest causative agent of H. pylori, in increasing the risk of gastric MALT lymphoma remains unclear and controversial. A systematic review and meta-analysis were conducted to evaluate the effect of cagA status on the development of gastric MALT lymphoma.MethodsAll articles evaluating the status of the cagA gene in the development of gastric MALT lymphoma were collected using systematic searches in online databases, including PubMed, Scopus, Embase, and Google Scholar, regardless of publication date. The association between cagA and gastric MALT lymphoma was assessed using the odds ratio (OR) summary. In addition, a random-effects model was used in cases with significant heterogeneity.ResultsA total of 10 studies met our inclusion criteria, among which 1860 patients participated. No association between cagA status and the development of MALT lymphoma (extranodal marginal zone B-cell lymphoma) was found in this study (OR 1.30; 0.906–1.866 with 95% CIs; I2: 45.83; Q-value: 12.92). Surprisingly, a meaningful association was observed between cagA status and diffuse large B-cell lymphoma (OR 6.43; 2.45–16.84 with 95% CIs). We also observed an inverse association between vacA and gastric MALT lymphoma risk (OR 0.92; 0.57–1.50 with 95% CIs).ConclusionsIt seems that the infection with cagA-positive H. pylori strains does not have a meaningful effect on the gastric MALT lymphoma formation, while translocated CagA antigen into the B cells plays a crucial role in the development of diffuse large B-cell lymphoma.

Gastrointestinal microbiome in the context of Helicobacter pylori infection in stomach and gastroduodenal diseases.

Infectious origins of a set of severe gastroduodenal diseases viz. gastritis, duodenal ulcer, gastric ulcer, gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma were appreciated only after the discovery of H. pylori in 1983. In the past two decades, however, findings from many laboratories suggest that apart from H. pylori, several of the trillions of microbes that populate the human gastrointestinal tract and form microbiomes of the respective niches (like oral microbiome, esophageal microbiome, gastric microbiome and intestinal microbiome) may also participate in maintaining the healthy state of stomach and duodenum. Dysbiosis leading to alteration in the relative abundance of the key gastrointestinal microbes is associated with severe gastric diseases. For instance, an increased abundance of genera like Leptotrichia, Prevotella and Veillonella in gastric microbiome and a decreased abundance of Bifidobacterium in intestinal microbiome are associated with gastric cancer. H. pylori infection, apart from causing direct harm to the gastric epithelium by its virulence proteins like vacuolating cytotoxin A (VacA) and cytotoxin associated gene A (CagA), is also capable of triggering dysbiosis in stomach and intestinal microbiomes. In this chapter, we have discussed the possible roles of bacteria, viruses, fungi, archaea, protozoa and helminths in human gastrointestinal tracts in the context of H. pylori infection in stomach and various gastroduodenal diseases.

Immunotherapy in indolent Non-Hodgkin's Lymphoma

Treatment of non-Hodgkin lymphoma (NHL) in general has improved over the years with the emergence of the monoclonal antibodies (MAB) therapy. NHL is divided into B cell NHL and T cell NHL. Treatment of NHL was based on the subtype of NHL and its staging. NHL is divided into aggressive and indolent NHL (iNHL). Subtypes of iNHL include: Follicular lymphoma (FL), Marginal zone lymphoma (MZL), Chronic lymphocytic leukemia/small-cell lymphocytic lymphoma (CLL/SLL), Gastric mucosa-associated lymphoid tissue (MALT) lymphoma, Lymphoplasmacytic lymphoma, Waldenström macroglobulinemia, Nodal marginal zone lymphoma (NMZL), Splenic marginal zone lymphoma (SMZL). Chemotherapy was the main stay treatment of iNHL until the emergence of Rituximab, anti-CD20 MAB targeting CD-20 surface cell antigens that are present on B-cells lymphoma and not on precursor cells, mainly efficacious in B cell iNHL, It became the mainstay treatment in follicular lymphoma (FL) as a single agent modality or in combination with chemotherapy. The anti-CD20 Rituximab played an important role in the development of the treatment of iNHL to become FDA approved in 1997. It was also proven effective in multiple other types of lymphoma. MAB through targeting the cell surface antigen leads to a direct or immune mediated cytotoxicity. This carries few side effects, including allergic reactions. Other than that, a resistance mechanism to rituximab emerged by inducing a failure in the apoptosis mechanism. Alternative mechanisms of resistance included the presence of soluble antigens that could act by binding to the antibody present before the drug itself can bind the lymphoma cell. Thus, the interest in immunotherapy grew further to explore the possibility of conjugating an immune mediated drug to a radio-sensitizing agent in order to enhance the selectivity of the drug. Here came the development of 90Y-ibritumomab tiuxetan and 131I-tositumomab. After it, humanized anti-CD20 emerged ofatumumab, IMMU106 (veltuzumab) in 2005, and ocrelizumab which are considered as second generation anti-CD20 and 3rd generation anti-CD20 include AME-133v (ocaratuzumab), PRO131921 and GA101 (obinutuzumab). Also multiple other agents emerged targeting different surface cell antigens like CD52 (alemtuzumab), CD22 (unconjugated epratuzumab and calicheamicin conjugated CMC-544 [inotuzumab ozogamicin]), CD80 (galiximab), CD2 (MEDI-507 [siplizumab]), CD30 (SGN-30 and MDX-060 [iratumumab], Brentuximab vedotin), CD40 (SGN-40), and CD79b (Polatuzumab). Other agents include MAB targeting T-Cells like mogamulizumab, Denileukin Diftitox and BiTEs or bispecific T cell engagers like Mosunetuzumab, Glofitamab, and Epcoritamab. Moreover, further studies came up to evaluate the role of immunotherapy in combination chemotherapy as a pathway to evade the resistance mechanisms. Side effects of the treatment were mainly infusion related adverse reactions, myelosuppression in conjugated forms leading to immunosuppression and subsequently to infectious complications. Another important aspect in immunotherapy is the half-lives of the medication which is an important factor that can influence the evaluation of the response. The MAB treatment showed important benefit in the treatment of iNHL and it continuously shows how rapidly it can develop to provide optimum care and benefit to patients with iNHL.

Prevalence of Helicobacter pylori infection and its association with blood groups in patients presenting epi-gastric pain in Umaru Shehu ultra-modern hospital, Maiduguri, Nigeria

Helicobacter pylori is a gram-negative bacterium that causes peptic ulcer and is also involved in gastric mucosa-associated lymphoid tissue lymphomas. The objective of the present study was to determine seroprevalence of Helicobacter pylori among patients complaining of epigastric pain at Umaru Shehu ultra-modern hospital Maiduguri, Nigeria. A rapid diagnostic cassette test kit for the qualitative detection of Helicobacter pylori was used in this study. A random sampling technique was used to collect blood samples and obtain other demographic variables that include sex, age and blood group which are considered as risk factors for contracting Helicobacter pylori. Out of the 50 patients tested, 45 (90.0%) were positive. The positive patients comprised 10 out of 12 males (83.3%) and 35 out of 38 females (92.1%). Patients within the age groups 10-20, 31-40 and >50 years had a prevalence of 100% each, while patients between 21-30 years and those 41-50 years had a prevalence of 88.9% and 62.5% respectively. When their blood groups were considered, the AB group had a prevalence of 100% followed by the A group (95%) while the O and B groups had 90.5% and 75%, respectively. Patients complaining of epigastric pain should be screened for Helicobacter pylori, particularly in early cases and among people living in clusters or under inadequate sanitary conditions, such as internally displaced persons.

HomA and HomB, outer membrane proteins of Helicobacter pylori down-regulate activation-induced cytidine deaminase (AID) and Ig switch germline transcription and thereby affect class switch recombination (CSR) of Ig genes in human B-cells

H. pylori is one of the major causes of chronic gastritis, peptic ulcer disease (PUD), gastric mucosa-associated lymphoid tissue lymphoma (MALT) and gastric carcinoma. H. pylori toxin VacA is responsible for host cell apoptosis, whereas CagA is known to aberrantly induce expression of activation-induced cytidine deaminase (AID) in gastric epithelial cells that causes mutations in oncogenes and tumour suppressor genes, leading to the transformation of normal cells into cancerous cells. Although, a significant amount of research has been conducted to understand the role of bacterial factors modulating deregulated host cell pathways, the interaction between H. pylori and immune cells of the marginal zone and its consequences are still not well understood. HomB and HomA, outer membrane proteins (OMPs) from H. pylori, which assist in the adhesion of bacteria to host cells, are found to be associated with H. pylori virulent strains and promote inflammation. Interestingly, we observed that the interaction of HomB/HomA OMPs with B-cells transiently downregulates AID expression and Ig switch germline transcription. Downregulation of AID leads to impairment of class switch recombination (CSR), resulting in significantly reduced switching to IgG and IgA antibodies. Besides, we examined the immune-suppressive response of B-cells and observed that the cells stimulated with HomA/B show upregulation in the levels of IL10, IL35, as well as PDL1, a T-cell inhibition marker. Our study suggests the potential role of OMPs in immune response modulation strategies used by the pathogen to evade the immune response. These results provide a better understanding of H. pylori pathogenesis and assist in identifying novel targets for therapy.

Helicobacter pylori Eradication and Gastric Cancer Prevention

Since Warren and Marshall demonstrated Helicobacter pylori (H. pylori) as a cause of gastritis in the early 1980s, H. pylori has been associated with various gastric diseases, including gastric ulcer, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, gastric adenoma, gastric adenocarcinoma, and hyperplastic gastric polyps. H. pylori eradication therapy can treat some associated diseases, including low-grade gastric MALT lymphoma, and significantly reduce the risk of peptic ulcer recurrence or progression of atrophic gastritis and intestinal metaplasia. In East Asia, where H. pylori and gastric cancer are prevalent, several studies have been conducted to prove whether the risk of gastric cancer development is reduced through H. pylori eradication therapy. Early studies failed to show the benefits of H. pylori eradication therapy in gastric cancer prevention. However, recent studies with extended follow-up periods have reported reduced risks of gastric cancer after treatment of H. pylori infection. H. pylori eradication therapy effectively prevents gastric cancer even in patients who were treated for early gastric cancer, and can be used in treating hyperplastic gastric polyps. Herein, we reviewed current evidence supporting the benefits of H. pylori eradication therapy to help clinicians understand its impact on gastric cancer prevention and hyperplastic polyp treatment.

Child With Extranodal Marginal Zone B-cell Lymphoma of Mucosa-associated Lymphoid Tissue

Many patients present to our clinic with Helicobacter pylori (H. pylori) infection. Most have nonspecific symptoms that cannot be immediately attributed to H. pylori. The joint European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN)/North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) guidelines recommend upper gastroscopy to detect the cause of such symptoms. Herein, we present the case of a 9-year-old girl diagnosed with gastric mucosa-associated lymphoid tissue lymphoma associated with H. pylori infection using upper gastroscopy. We believe that a patient of such a young age with this serious condition secondary to H. pylori will highlight the importance of upper gastrointestinal endoscopy in such cases.

Radiotherapy for gastric mucosa-associated lymphoid tissue lymphoma.

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is a rare disease which is often associated with Helicobacter pylori (H. pylori) infection. First-line treatment of stage IE and IIE localized gastric MALT lymphoma is based on the eradication of H. pylori. The presence of H. pylori resistance factors such as translocation t (11;18), peri-gastric lymph node involvement and the degree of tumor infiltration of the gastric wall; or lack of response to antibiotic therapy are two main indications to treat with definitive radiotherapy (RT). RT is an effective treatment in localized gastric MALT lymphoma. A moderate dose of 30 Gy allows a high cure rate while being well tolerated. After treatment, regular gastric endoscopic follow-up is necessary to detect a potential occurrence of gastric adenocarcinoma.

Long-Term Clinical Outcomes of Gastric MALT Lymphoma: A Nationwide Multicenter Study in Korea.

BackgroundTreatment recommendations for gastric mucosa-associated lymphoid tissue (MALT) lymphoma are based on case series and expert opinions. Only a few previous studies have focused on the long-term outcomes of gastric MALT lymphoma, especially according to stage.MethodsPatients diagnosed with gastric MALT lymphoma from January 2000 to December 2018 at nine university hospitals in Korea were included. Clinical data of medical history, endoscopic features, histological diagnosis, results of Helicobacter pylori (H. pylori) testing, stage, treatment conditions, and outcomes were collected.ResultsA total of 1,163 patients was enrolled, and 97.6% (n=1,038) of patients were diagnosed as stage IE. 10-year overall survival (OS) for the entire population was 99.1% and was better for patients in stage IE compared with patients in stage III/IV (p=0.002). The 10-year OS for H. pylori-positive patients was better than that of H. pylori-negative patients (p=0.022). Multivariate analyses revealed initial stage III/IV as a prognostic factor associated with over-all survival.ConclusionThe majority of gastric MALT lymphoma patients are diagnosed at an early localized stage in Korea. The overall survival rate of gastric MALT lymphoma is excellent and is associated with the initial stage of the disease.

Helicobacter pylori and Respiratory Diseases: 2021 Update.

Helicobacter pylori (H. pylori) is a Gram-negative bacterium involved in the development of gastritis, peptic ulcer disease, gastric adenocarcinoma, and gastric mucosa-associated lymphoid tissue. Unexplained iron deficiency anemia, idiopathic thrombocytopenic purpura and vitamin B12 deficiency have also been related to H. pylori infection, whereas for other extra-gastric diseases, the debate is still open. In this review, we evaluate and discuss the potential involvement of H. pylori infection in the pathogenesis of several respiratory diseases. A MEDLINE search of all studies published in English from 1965 to 2021 was carried out. Controversial findings have been reported in patients with bronchial asthma, chronic obstructive pulmonary disease, bronchiectasis, lung cancer, tuberculosis, cystic fibrosis, and sarcoidosis. Most of the available literature is concerned with case-control studies based on seroprevalence, with a small sample size and low consideration of confounders, which represents a potential issue. So far, there is no clear evidence of a causal association between H. pylori infection and respiratory diseases, and larger studies with appropriate epidemiological design are required.

CXCR4 PET/MRI for follow-up of gastric mucosa–associated lymphoid tissue lymphoma after first-line Helicobacter pylori eradication

AbstractPosttreatment evaluation of gastric mucosa-associated lymphoid tissue (MALT) lymphoma currently relies on esophagogastroduodenoscopy with histological assessment of biopsies. Overexpression of the G protein–coupled C-X-C chemokine receptor type 4 (CXCR4) has been previously observed in MALT lymphoma. The aim of this prospective study was to evaluate positron emission tomography (PET) with the novel CXCR4 tracer [68Ga]Pentixafor as a potential alternative to follow up biopsies for assessment of residual disease (noncomplete remission [CR]) after first-line Helicobacter pylori eradication. Forty-six post–H pylori eradication [68Ga]Pentixafor–PET/magnetic resonance imaging (MRI) examinations of 26 gastric MALT lymphoma patients, and 20 [68Ga]Pentixafor–PET/MRI examinations of 20 control group patients without lymphoma, were analyzed. In the MALT lymphoma group, time-matched gastric biopsies were used as reference standard and showed CR in 6 cases. Pooled examination-based accuracy, sensitivity, specificity, and positive and negative predictive values of [68Ga]Pentixafor–PET for detection of residual gastric MALT lymphoma at follow-up were 97.0%, 95.0%, 100.0%, 100.0%, and 92.9%, respectively. Maximum and mean PET standardized uptake values showed moderate correlation with immunohistochemistry-based CXCR4+ cell counts, with correlation coefficients of r = 0.51 and r = 0.52 (P = .008 and P = .006). In summary, CXCR4 imaging with [68Ga]Pentixafor–PET may represent a promising test for assessment of residual gastric MALT lymphomas after H pylori eradication.

Synthesis and characterization of amoxicillin-loaded polymeric nanocapsules as a drug delivery system targeting Helicobacter pylori

Background and study aimsHelicobacter pylori (H. pylori) is well known as the main cause of gastritis, gastroduodenal ulcers, gastric mucosa-associated lymphoid tissue lymphoma, and gastric cancer. Approximately 50% of the world’s population is infected with H. pylori. In Egypt, a high prevalence of H. pylori infections has been reported in the general population. This study aimed to prepare amoxicillin-loaded poly (ɛ-caprolactone) nanocapsules to increase its gastric stability and therapeutic activity of the molecule against H. pylori. Materials and methodsIn this study, we used the water–oil–water double-emulsion technique to prepare spherical-shaped polymeric nanocapsules containing amoxicillin trihydrate as the core substance and biodegradable biocompatible poly (ɛ-caprolactone) as the shell material. ResultsThe encapsulation efficiency obtained was 97.2% ± 0.8%. The hydrodynamic diameter of the prepared nanocapsules was 287 ± 8 nm with a positive zeta potential. In vitro release studies indicated that the polymeric nanocapsules showed decreased release percentages at pH 1.2, simulating the gastric fluid while relatively increased release at pH 7.0 where the H. pylori reside. The in vitro antibacterial assay showed better efficiency for amoxicillin nanocapsules than for the uncapsulated free amoxicillin, no efficiency was detected for the PCL nanocapsules indicated that the antibacterial due to amoxicillin alone. Cytotoxicity studies demonstrated less cytotoxicity for the polymeric nanocapsules in comparison with amoxicillin. ConclusionsIn conclusion, we have demonstrated that biodegradable polymeric nanocapsules are useful drug delivery agents for increasing the gastric stability and therapeutic activity of amoxicillin trihydrate against H. pylori.

The Helicobacter pylori CagY Protein Drives Gastric Th1 and Th17 Inflammation and B Cell Proliferation in Gastric MALT Lymphoma.

Background: the neoplastic B cells of the Helicobacter pylori-related low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma proliferate in response to H. pylori, however, the nature of the H. pylori antigen responsible for proliferation is still unknown. The purpose of the study was to dissect whether CagY might be the H. pylori antigen able to drive B cell proliferation. Methods: the B cells and the clonal progeny of T cells from the gastric mucosa of five patients with MALT lymphoma were compared with those of T cell clones obtained from five H. pylori–infected patients with chronic gastritis. The T cell clones were assessed for their specificity to H. pylori CagY, cytokine profile and helper function for B cell proliferation. Results: 22 of 158 CD4+ (13.9%) gastric clones from MALT lymphoma and three of 179 CD4+ (1.7%) clones from chronic gastritis recognized CagY. CagY predominantly drives Interferon-gamma (IFN-γ) and Interleukin-17 (IL-17) secretion by gastric CD4+ T cells from H. pylori-infected patients with low-grade gastric MALT lymphoma. All MALT lymphoma-derived clones dose dependently increased their B cell help, whereas clones from chronic gastritis lost helper activity at T-to-B-cell ratios greater than 1. Conclusion: the results obtained indicate that CagY drives both B cell proliferation and T cell activation in gastric MALT lymphomas.

The TLR4–TRIF–type 1 IFN–IFN-γ pathway is crucial for gastric MALT lymphoma formation after Helicobacter suis infection

SummaryHelicobacter suis, a zoonotic infection-related bacterium, can induce gastric mucosa-associated lymphoid tissue (MALT) lymphoma in humans and animals. Recently, we reported that the formation of gastric MALT lymphoma after H. suis infection is induced by interferon (IFN)-γ activation. Here, we revealed that activation of the Toll-like receptor (TLR) 4–Toll/IL-1 receptor domain-containing adapter-inducing interferon-β (TRIF) pathway after H. suis infection is associated with the production of type 1 IFNs (IFN-α, IFN-β) by gastric epithelial cells. Additionally, these type 1 IFNs interact with type 1 IFN receptors on gastric B cells, facilitating the secretion of IFN-γ and the activation of which is enhanced by positive feedback regulation in B cells. These results suggest that the TLR4–TRIF-type 1 IFN–IFN-γ pathway is crucial in the development of gastric MALT lymphoma after H. suis infection and may, therefore, represent a therapeutic target for the prevention of this condition.