Helicobacter pylori infection and gastric lymphoma

Molecular evolution of the VacA p55 binding domain of Helicobacter pylori in mestizos from a high gastric cancer region of Colombia

The stomach bacterium Helicobacter pylori is one of the most prevalent pathogens in humans, closely linked with serious diseases such as gastric cancer. The microbe has been associated with its host for more than 100,000 years and escorted modern humans out of Africa. H. pylori is predominantly transmitted within families and dispersed globally, resulting in distinct phylogeographic patterns, which can be utilized to investigate migrations and bioturbation events in human history. Latin America was affected by several human migratory waves due to the Spanish colonisation that drastically changed the genetic load and composition of the bacteria and its host. Genetic evidence indicates that independent evolutionary lines of H. pylori have evolved in mestizos from Colombia and other countries in the region during more than 500 years since colonisation. The vacuolating cytotoxin VacA represents a major virulence factor of the pathogen comprising two domains, p33 and p55, the latter of which is essential for binding to the host epithelial cell. The evolution of the VacA toxin in Colombia has been strongly biased due to the effects of Spanish colonization. However, the variation patterns and microevolution of the p55 domain have not yet been described for this population. In the present study, we determined the genetic polymorphisms and deviations in the neutral model of molecular evolution in the p55 domain of 101 clinical H. pylori isolates collected in Bogotá, a city located in Andean mountains characterized by its high gastric cancer risk and its dominant mestizo population. The microevolutionary patterns of the p55 domain were shaped by recombination, purifying and episodic diversifying positive selection. Furthermore, amino acid positions 261 and 321 in the p55 domain of VacA show a high variability among mestizos clinical subsets, suggesting that natural selection in H. pylori may operate differentially in patients with different gastric diseases.

Cancers attributable to infections in Canada

Infections are estimated to cause approximately 15% of the world's cancers with large geographic variations. Yet, Canadian estimates for specific cancer-causing infections are not available. To estimate the number of infection-associated cancers diagnosed among Canadian adults in 2015, we calculated population attributable risks (PARs) and the number of attributable cases for seven carcinogenic infections and their 20 associated cancers. A systematic literature search was performed for each infection to obtain data on infection prevalence in the population and the relative risk or odds ratio associated with the cancer it causes. When mechanistic evidence suggested that detection of a given infection within cancer tissue was sufficient to attribute the cancer to the infection, prevalence among cancer cases was used to approximate the PAR. Data from 61 studies formed the basis of our analyses. The estimated number of infection-attributable cancer cases for 2015 was: 3828 for human papillomavirus (HPV), 2052 for Helicobacter pylori, 578 for Epstein-Barr virus, 509 for hepatitis B and C viruses (HBV, HCV), 100 for human herpesvirus type 8, and 30 cases for human T-cell lymphotropic virus type 1. These seven infections were responsible for 3.7% of cancers diagnosed among Canadian adults in 2015; 3.5% among men and 4.0% among women. The infections with the highest number of attributable cases are largely preventable or treatable through vaccination (HBV and HPV), antibiotic therapy (H. pylori), or a combination of interventions (HCV), thereby representing an important target for reducing the infection-caused cancer burden among Canadians.

Concomitant occurrence of primary renal non-Hodgkin lymphoma and a colon cancer: A rare case report

RATIONALE

Primary renal lymphoma (PRL) is a rare malignancy due to the absence of lymphatic tissues in the kidney, and patients with PRL have been reported to have a poor prognosis due to its rapid invasiveness and limited treatment strategies. Colon cancer is the third most common cancer, and has a high mortality rate. Both malignant diseases predominantly affected elderly men; however, a case with concomitant occurrence of the 2 cancers is extremely rare.

PATIENT CONCERNS

A 78-year-old male patient with abdominal pain came to our hospital. Computed tomography (CT) indicated malignant masses in the left kidney, left adrenal gland, and the lower part of the descending colon.

DIAGNOSES

PRL and colon cancer were diagnosed based on pathological examinations.

INTERVENTIONS

The patient was treated with laparoscopic radical nephrectomy and laparoscopic radical resection of colon cancer.

OUTCOMES

The patient was then transferred to the intensive care unit (ICU) because of poor condition after surgery. He died 3 months after discharge without receiving any other treatment.

LESSONS

It is worth thinking about whether surgery was reasonable for elderly patients with double malignancies, or palliative treatment to improve the quality of life was more meaningful. This case also contributes to the understanding of the 2 malignancies and highlights the need to pay more attention to patients with multiple primary malignant neoplasms (MPMNs), explore genetic features, and investigate treatments with more survival benefits.

Evaluation of the Epidemiologic Efficacy of Eradicating Helicobacter pylori on Development of Gastric Cancer

Eradication of Helicobacter pylori colonization has been reported to affect the progression of gastric cancer. A comprehensive literature search was performed from 1997 to 2017 using electronic databases. All randomized controlled trials (RCTs) and nonrandomized controlled trials (non-RCT) evaluated the effect of H. pylori eradication on development of gastric cancer. Four RCTs and 9 non-RCTs were included (n = 40,740 participants; 321,269 person-years). Overall, H. pylori eradication therapy was associated with a significantly reduced risk of gastric cancer (incidence rate ratio (IRR) = 0.52, 95% confidence interval (CI): 0.41, 0.65). Results of mixed-effect Poisson regression meta-analysis were similar to those of traditional meta-analyses. In stratified analyses, the IRRs were 0.59 (95% CI: 0.41, 0.86) in RCTs and 0.48 (95% CI: 0.36, 0.64) in non-RCTs. The IRRs were 0.45 (95% CI: 0.34, 0.61) in patients and 0.63 (95% CI: 0.44, 0.90) in the general population. Moreover, the relative risk reduction was approximately 77% on the development of noncardiac gastric cancer with H. pylori eradication therapy in China. Attributable risk percentage and population attributable risk percentage for Chinese patients were 77.08% and 75.33%, respectively, and for Japanese patients were 57.80% and 45.99%, respectively. H. pylori eradication therapy reduces the risk of noncardiac gastric cancer development. The findings indicate the importance of early intervention with H. pylori eradication therapy from the perspective of epidemiology.

MALT Lymphoma as a Model of Chronic Inflammation-Induced Gastric Tumor Development

Mucosa-associated lymphoid tissue (MALT) lymphoma, or extranodal marginal zone lymphoma of MALT, is an indolent B-cell non-Hodgkin lymphoma linked with preexisting chronic inflammation. The stomach is the most commonly affected organ and the MALT lymphoma pathogenesis is clearly associated with Helicobacter pylori gastroduodenitis. Inflammation induces the lymphoid infiltrates in extranodal sites, where the lymphoma then subsequently develops. Genetic aberrations arise through the release of reactive oxygen species (ROS), H. pylori-induced endonucleases, and other effects. The involvement of nuclear factor kappa B (NF-κB) pathway activation, a critical regulator of pro-inflammatory responses, further highlights the role of inflammation in gastric MALT lymphoma. The NF-κB pathway regulates key elements of normal lymphocyte function, including the transcription of proliferation-promoting and anti-apoptotic genes. Aberrant constitutive activation of NF-κB signaling can lead to autoimmunity and malignancy. NF-κB pathway activation can happen through both the canonical and non-canonical pathways and can be caused by multiple genetic aberrations such as t(11;18)(q12;q21), t(1;14)(p22;q32), and t(14;18)(q32;q21) translocations, chronic inflammation and even directly by H. pylori-associated mechanisms. Gastric MALT lymphoma is considered one of the best models of how inflammation initiates genetic events that lead to oncogenesis, determines tumor biology, dictates clinical behavior and leads to viable therapeutic targets. The purpose of this review is to present gastric MALT lymphoma as an outstanding example of the close pathogenetic link between chronic inflammation and tumor development and to describe how this information can be integrated into daily clinical practice.

Helicobacter pylori: History and facts in Peru

Helicobacter pylori (H. pylori) is a cosmopolite bacteria and the main responsible for the high burden of gastric cancer in developing countries, such as Peru. In this review, we describe some historical facts in the H. Pylori discovery, the first researches of this bacterium in Peru, as well as its epidemiology, clinical characteristics, diagnosis, treatments, and outcomes. Our literature and review of real-life data suggest that several efforts should be conducted in our country to deal with antibiotic-resistance and lack of adherence to treatment in order to reduce our incidence of gastric cancer.

Coxiella burnetii in non-Hodgkin lymphoma tissue samples: Innocent until proven otherwise?

PURPOSE

Coxiella burnetii has been suggested as a potential cause of B-cell non-Hodgkin lymphoma (B-NHL), as C. burnetii was detected in B-NHL tissues. To further investigate this potential relationship, we hypothesized that among subjects previously exposed to C. burnetii, the bacterium is more frequently detectable in tissues of patients with B-NHL (cases) compared to patients without B-NHL (controls).

METHODS

We aimed to evaluate this hypothesis by assessing the presence of C. burnetii with polymerase chain reaction (PCR), immunofluorescence staining (IF) and fluorescent in-situ hybridization (FISH). Eligible patients were those previously exposed to C. burnetii.

RESULTS

Samples were available for 13 cases and 16 controls. C. burnetii was demonstrated in tissues of 8/29 patients in total (28%), with either PCR, IF or FISH: in 5/13 cases (38%) and 3/16 controls (19%), p = 0.41. Negative and positive control samples were all negative and positive appropriately for all three diagnostic methods.

CONCLUSIONS

In patients previously exposed to C. burnetii the bacterium was detected in tissue samples from subjects with and without B-NHL, without significant differences in the proportion positive samples. Therefore, we conclude that detection of C. burnetii in tissues of patients previously exposed to C. burnetii is a non-specific finding.

Sero-prevalence of Helicobacter pylori CagA immunoglobulin G antibody, serum pepsinogens and haemoglobin levels in adults

Associations observed of Helicobacter pylori infection with haemoglobin levels are inconsistent. We examined associations of H. pylori sero-prevalence and serum pepsinogens (PGs), as non-invasive markers of atrophic gastritis, with haemoglobin levels. A cross-sectional study was undertaken among 654 Jewish and 937 Arab residents of Jerusalem, aged 25–78 years, randomly selected from Israel’s national population registry in age-sex and population strata. Sera were tested for H. pylori IgG, cytotoxin–associated gene A (CagA) antigen IgG antibody and PGs levels. Multivariable models were fitted to account for confounders. Participants with atrophic gastritis (PGI < 30 μg/L or a PGI: PGII < 3.0) had lower haemoglobin levels than those without: beta-coefficient −0.34 (95% CI −0.59, −0.09); in men −0.27 (95% CI −0.67, 0.12), and in women −0.43 (95% CI −0.74, −0.12). Lower haemoglobin levels were noted in persons with CagA antibody than in those H. pylori sero-negative or H. pylori-CagA sero-negative: beta-coefficient −0.14 (95% CI −0.29, 0.01). Anaemia was more common among women and men with than without atrophic gastritis: adjusted OR 2.58 (95% CI 1.48, 4.48) and 1.52 (95% CI 0.59, 3.95), respectively. In conclusion, independent of known correlates, atrophic gastritis and apparently CagA sero-positivity, a marker of H. pylori virulent strains, are associated with lower haemoglobin levels.

Primary Gastric Lymphoma, Epidemiology, Clinical Diagnosis, and Treatment

Primary gastric lymphoma (PGL) is the most common extranodal non-Hodgkin lymphoma and represents a wide spectrum of disease, ranging from indolent low-grade marginal zone lymphoma or mucosa-associated lymphoid tissue (MALT) lymphoma to aggressive diffuse large B-cell lymphoma. The PGL is a relatively rare cancer and easily misdiagnosed due to its unspecific symptoms of the digestive tract. The medical literature and ongoing clinical trials were reviewed on the clinical presentation, diagnosis, prognosis, prevention, and treatment of PGL. Primary gastric lymphoma is an event in the course of cancer with a variable clinical presentation and a wide differential diagnosis. Chronic gastritis secondary to Helicobacter pylori (H pylori) infection has been considered a major predisposing factor for MALT lymphoma. Magnetic resonance imaging and endoscopic ultrasonography have helped in staging of these cancers. The clinical course and prognosis of this disease are dependent on histopathological subtype and stage at the time of diagnosis. A global therapeutic approach to the cure of PGL has completely changed over the past 10 years, including innovative and conservative options to reduce treatment toxicity. Due to the rarity of PGL, many aspects of this neoplasm are still controversial. The incidence of this disease is increasing, making it necessary for clinicians to understand the clinical symptoms, workup, and treatment of these lymphomas.

Helicobacter pylori infection and inflammatory bowel disease: a crosstalk between upper and lower digestive tract

Helicobacter pylori has coexisted with humans for approximately 60,000 years and greater than 50% of the global population is infected with H. pylori. H. pylori was successfully cultured in vitro in 1983 and studies of H. pylori have achieved substantial advances over the last 35 years. Since then, H. pylori has been characterized as the primary pathogenic factor for chronic gastritis, peptic ulcer, and gastric malignancy. Numerous patients have received H. pylori eradication treatment, but only 1-2% of H. pylori-infected individuals ultimately develop gastric cancer. Recently, numerous epidemiological and basic experimental studies suggested a role for chronic H. pylori infection in protecting against inflammatory bowel disease (IBD) by inducing systematic immune tolerance and suppressing inflammatory responses. Here we summarize the current research progress on the association between H. pylori and IBD, and further describe the detailed molecular mechanism underlying H. pylori-induced dendritic cells (DCs) with the tolerogenic phenotype and immunosuppressive regulatory T cells (Tregs). Based on the potential protective role of H. pylori infection on IBD, we suggest that the interaction between H. pylori and the host is complicated, and H. pylori eradication treatment should be administered with caution, especially for children and young adults.

Treatment of mucosa associated lymphoid tissue lymphoma with a long-term once-weekly regimen of oral azithromycin: Results from the phase II MALT-A trial

The macrolide clarithromycin has been reported as active for therapy of mucosa associated lymphoid tissue (MALT) lymphoma. Pharmacokinetic properties, however, require continuous daily intake over a prolonged period of time. As the macrolide azithromycin is characterized by a long half‐life as well as potential antineoplastic activity in vitro, we have performed a phase II trial of long‐term once‐weekly oral azithromycin for treatment of MALT lymphoma. In a 2‐stage‐design, 16 patients (10 f/6 m) with histologically verified and measurable MALT lymphoma were included in the first phase of the trial, which could be expanded to a maximum of 46 patients depending on remissions in the first phase. Patients were given oral azithromycin 1500 mg once‐weekly 4 times a month, and restaging was performed after 3 and 6 months. Two patients had gastric and 14 extragastric MALT lymphoma; 12/16 patients were treatment‐naive and received azithromycin as first line treatment. Tolerance of this regimen was excellent, and 14/16 patients received 6 months of treatment as scheduled, while 1 patient each discontinued after 4 (progressive disease) and 1 cycle (personal reasons), respectively. The most commonly observed side effects were mild nausea (n = 8) and diarrhea (n = 4). Efficacy, however, was low as only 4/16 patients (25%) responded, with 2 complete and 2 partial remissions, 9 patients (56%) had stable disease, and 3 patients 19%) were rated as progressive disease. As the predefined activity of more than 7/16 patients responding was not reached, the study was stopped after 16 patients. Although long‐term once‐weekly oral azithromycin showed some antilymphoma activity, the response rate was below the predefined threshold of interest. However, based on our data, one cannot rule out suboptimal dosing in our study; attempts to study azithromycin at a different mode of application might be warranted in the future.

Zinc Oxide Tetrapods Based Biohybrid Interface for Voltammetric Sensing of Helicobacter pylori

Helicobacter pylori is a Gram-negative, spiral shaped, microaerophilic bacteria that colonizes human gastric mucosa and causes various gastric diseases. In this work, the utilization of ion irradiated zinc oxide tetrapods (ZnO-T) based biohybrid interface accentuates the development of an electrochemical immunosensor for the fast and sensitive detection of H. pylori. After coating of (ZnO-T) over the surface of screen printed electrode (SP-AuE) through electrodeposition, the ZnO-T/SP-AuE was irradiated with N₂⁺ ion of energy 100 keV. The ion irradiation significantly enhances the conductivity of ZnO-T coated SP-AuE. The revamped SP-AuE is further used for establishing an immunosensor interface based upon immobilization of the CagA antigen on ZnO-T electrodeposited over the surface of SP-AuE. The sensing interface demonstrated good linearity (0.2 ng/mL to 50 ng/mL) and limit of detection (0.2 ng/mL). The ion beam irradiated ZnO-T based immunosensor showed significantly high conductivity and enhanced the analytical properties of the working electrode in terms of the sensitivity, detection limit, and response time. A study on the comparison of irradiated and pristine electrode is performed for amperometric sensing of H. pylori. In addition, the significance of work conducted on ion irradiated ZnO-T based interfaces provides a basis of further development of electrochemical immunosensors.

A comparative study on Helicobacter pylori infection in Tibetan and Han people from Tibet and Sichuan province

AIM

To compare the prevalence of Helicobacter pylori (H. pylori) infection in Tibetan and Han subjects from Tibet and Sichuan province.

METHODS

A retrospective study for investigating H. pylori infection was performed among Tibetan and Han subjects who underwent the ¹⁴C-urea breath test at the Tibetan Chengdu Branch Hospital and West China Hospital. The clinical characteristics (residential address, H. pylori infection status, etc.) were collected and recorded.

RESULTS

A total of 2163 subjects from Tibet (Tibetan/Han, 547/297) and Sichuan province (Tibetan/Han, 308/1011) were enrolled in this retrospective study. The overall H. pylori positive rate in Tibet was significantly lower than that in Sichuan province (50.8% vs 39.3%, P < 0.001). The H. pylori positive rate in Tibetan subjects from both Tibet and Sichuan was significantly higher than that in Han people (56.9% vs 39.7%, P < 0.001; 52.3% vs 35.4%, P < 0.001). No significant difference was observed in the H. pylori positive rate between Tibetan subjects from Tibet and Sichuan (P = 0.196) or Han subjects from Tibet and Sichuan (P = 0.192). The H. pylori positive rate of Han ethnic subjects significantly increased in the older age group (age < 45 vs age ≥ 45: 32.3% vs 40.5%, P = 0.002). However, the H. pylori positive rate of Tibetan subjects significantly decreased in the older age group (age < 45 vs age ≥ 45: 61.5% vs 50.0%, P = 0.001).

CONCLUSION

The H. pylori prevalence rate is higher in Tibetan subjects than in Han subjects from Sichuan province and Tibet. The H. pylori prevalence rate is positively correlated with age in Han subjects, but is negatively correlated with age in Tibetan subjects.

Structural studies and molecular dynamics simulations suggest a processive mechanism of exolytic lytic transglycosylase from Campylobacter jejuni

The bacterial soluble lytic transglycosylase (LT) breaks down the peptidoglycan (PG) layer during processes such as cell division. We present here crystal structures of the soluble LT Cj0843 from Campylobacter jejuni with and without bulgecin A inhibitor in the active site. Cj0843 has a doughnut shape similar but not identical to that of E. coli SLT70. The C-terminal catalytic domain is preceded by an L-domain, a large helical U-domain, a flexible linker, and a small N-terminal NU-domain. The flexible linker allows the NU-domain to reach over and complete the circular shape, using residues conserved in the Epsilonproteobacteria LT family. The inner surface of the Cj0843 doughnut is mostly positively charged including a pocket that has 8 Arg/Lys residues. Molecular dynamics simulations with PG strands revealed a potential functional role for this pocket in anchoring the negatively charged terminal tetrapeptide of the PG during several steps in the reaction including homing and aligning the PG strand for exolytic cleavage, and subsequent ratcheting of the PG strand to enhance processivity in degrading PG strands.

Primary Gastric Lymphoma: Clinicopathological Profile

Introduction

Gastrointestinal tract (GIT) is the most common site of involvement of extranodal non-Hodgkin’s lymphoma (NHL). There is regional variation in anatomical distribution of extranodal NHL, stomach being the most common site followed by small intestine. Primary gastric lymphoma (PGL) predominantly involves the antrum and corpus of the stomach. It arises from mucosa-associated lymphoid tissue (MALT) and is of B-cell lineage and often associated with Helicobacter pylori infection. Primary gastric lymphoma often presents with nonspecific symptoms. The present study was undertaken to ascertain the clinicopathological characteristics of PGL at a tertiary care center in South India.

Materials and methods

It is a retrospective study from 2006 to 2016. Patient’s data were obtained from institutional medical records. The histopathology slides were reviewed. The relevant immunohistochemistry (IHC) markers done were leukocyte common antigen (LCA), CD3, CD20, CD79a, CD10, Bcl-2, Bcl-6, CD5, Cyclin D1, CD138, and Ki-67. Correlating with the immunoprofile, further subtyping was done.

Results

A total of 405 patients of NHL were seen during the study period, out of which 43 patients were PGL. There were 32 males and 11 females, with M:F of 2.9:1. The mean age at diagnosis was 58 years. Abdominal pain and new-onset dyspepsia were the commonly observed presenting symptoms. The common site of involvement was antrum (20). Diffuse large B-cell lymphoma (DLBCL) was the most common histological subtype. Helicobacter pylori infection was seen in 18 (41%) patients. Majority of the patients were in stages II and III.

Conclusion

In our study, the initial presentation of PGL was with nonspecific symptoms like abdominal pain and new-onset dyspepsia. High degree of suspicion of such symptoms and biopsy of all suspicious lesions is essential for early detection. Diffuse large B-cell lymphoma was the most common histological subtype seen in our study.

How to cite this article: Malipatel R, Patil M, Rout P, Correa M, Devarbhavi H. Primary Gastric Lymphoma: Clinicopathological Profile. Euroasian J Hepato-Gastroenterol 2018;8(1):6-10.

The Pivotal Role of DNA Repair in Infection Mediated-Inflammation and Cancer

Pathogenic and commensal microbes induce various levels of inflammation and metabolic disease in the host. Inflammation caused by infection leads to increased production of reactive oxygen species (ROS) and subsequent oxidative DNA damage. These in turn cause further inflammation and exacerbation of DNA damage, and pose a risk for cancer development. Helicobacter pylori-mediated inflammation has been implicated in gastric cancer in many previously established studies, and Fusobacterium nucleatum presence has been observed with greater intensity in colorectal cancer patients. Despite ambiguity in the exact mechanism, infection-mediated inflammation may have a link to cancer development through an accumulation of potentially mutagenic DNA damage in surrounding cells. The multiple DNA repair pathways such as base excision, nucleotide excision, and mismatch repair that are employed by cells are vital in the abatement of accumulated mutations that can lead to carcinogenesis. For this reason, understanding the role of DNA repair as an important cellular mechanism in combatting the development of cancer will be essential to characterizing the effect of infection on DNA repair proteins and to identifying early cancer biomarkers that may be targeted for cancer therapies and treatments.

Exposure to Coxiella burnetii and risk of non-Hodgkin lymphoma: a retrospective population-based analysis in the Netherlands

BACKGROUND

An association between Coxiella burnetii and non-Hodgkin lymphoma has been suggested. After a large Q fever epidemic in the Netherlands (2007-10), we postulated that the incidence of non-Hodgkin lymphoma would be increased during and after the epidemic in areas with a high endemicity of Q fever compared with those with low endemicity.

METHODS

We did a retrospective population-based analysis and calculated relative risks (RRs) of non-Hodgkin lymphoma during 1-year periods before, during, and after the Q fever epidemic, for areas with intermediate and high endemicity of Q fever compared with low endemic areas. We also calculated the RR of non-Hodgkin lymphoma in people with chronic Q fever compared with the general population.

FINDINGS

Between Jan 1, 2002, and Dec 31, 2013, 48 760 cases of non-Hodgkin lymphoma were diagnosed. The incidence of non-Hodgkin lymphoma ranged from 21·4 per 100 000 per year in 2002 to 26·7 per 100 000 per year in 2010. A significant association with non-Hodgkin lymphoma was noted in 2009 for areas with a high endemicity of Q fever compared with low endemic areas (RR 1·16, 95% CI 1·02-1·33; p=0·029); no further associations were noted in any other year or for areas with intermediate Q fever endemicity. Among 439 individuals with chronic Q fever, five developed non-Hodgkin lymphoma, yielding a crude absolute risk of 301·0 cases per 100 000 per year (RR 4·99, 95% CI 2·07-11·98; p=0·0003) compared with the general population in the Netherlands.

INTERPRETATION

These findings do not support the hypothesis that Q fever has a relevant causal role in the development of non-Hodgkin lymphoma. Several limitations, inherent to the design of this study, might lead to both underestimation and overestimation of the studied association.

FUNDING

Foundation Q-support and Institut Mérieux.

An assessment of drinking water contamination with Helicobacter pylori in Lima, Peru

BACKGROUND

Helicobacter pylori is a gut bacterium that is the primary cause of gastric cancer. H. pylori infection has been consistently associated with lack of access to sanitation and clean drinking water. In this study, we conducted time-series sampling of drinking water in Lima, Peru, to examine trends of H. pylori contamination and other water characteristics.

MATERIALS AND METHODS

Drinking water samples were collected from a single faucet in Lima's Lince district 5 days per week from June 2015 to May 2016, and pH, temperature, free available chlorine, and conductivity were measured. Quantities of H. pylori in all water samples were measured using quantitative polymerase chain reaction. Relationships between the presence/absence and quantity of H. pylori and water characteristics in the 2015-2016 period were examined using regression methods accounting for the time-series design.

RESULTS

Forty-nine of 241 (20.3%) of drinking water samples were contaminated with H. pylori. Statistical analyses identified no associations between sampling date and the likelihood of contamination with H. pylori. Statistically significant relationships were found between lower temperatures and a lower likelihood of the presence of H. pylori (P < .05), as well as between higher pH and higher quantities of H. pylori (P < .05).

CONCLUSIONS

This study has provided evidence of the presence of H. pylori DNA in the drinking water of a single drinking water faucet in the Lince district of Lima. However, no seasonal trends were observed. Further studies are needed to determine the presence of H. pylori in other drinking water sources in other districts in Lima, as well as to determine the viability of H. pylori in these water sources. Such studies would potentially allow for better understanding and estimates of the risk of infection due to exposure to H. pylori in drinking water.

Autoimmunity checkpoints as therapeutic targets in B cell malignancies

Targeted therapy of cancer typically focuses on inhibitors (for example, tyrosine kinase inhibitors) that suppress oncogenic signalling below a minimum threshold required for survival and proliferation of cancer cells. B cell acute lymphoblastic leukaemia and B cell lymphomas originate from various stages of development of B cells, which, unlike other cell types, are under intense selective pressure. The vast majority of newly generated B cells are autoreactive and die by negative selection at autoimmunity checkpoints (AICs). Owing to ubiquitous encounters with self-antigen, autoreactive B cells are eliminated by the overwhelming signalling strength of their autoreactive B cell receptor (BCR). A series of recent findings suggests that, despite malignant transformation, AICs are fully functional in B cell malignancies. This Opinion article proposes targeted engagement of AICs as a previously unrecognized therapeutic opportunity to overcome drug resistance in B cell malignancies.

HLA-G Gene Polymorphism in Egyptian Patients with Non-Hodgkin Lymphoma and its Clinical Outcome

BACKGROUND

Non-Hodgkin lymphoma (NHL) is a major cancer in Egypt and worldwide and has many risk factors including genes involved in the immune response.

AIM

we investigated the HLA-G 14bp gene polymorphism as a risk factor for NHL and its clinic pathologic features. The study involved 150 patients with NHL and 100 healthy control. Full histories, clinical examination, C.T scan and laboratory investigations such as CBC, LDH, ?2microglobulin and HCV RNA by qualitative real time PCR were performed for all subjects. HLA-G 14bp ins/del gene polymorphism was determined by PCR.

RESULTS

in our study, del/del, ins/del and dominant genotypes increased the risk of NHL by 11.01, 10.55 and 10.88 fold respectively (p<0.001) but the recessive genotype did not increase the risk of NHL (p=0.112). Cases with the del allele had a greater risk of NHL than those with the ins allele (p<0.001). del/del and ins/del genotypes were significantly associated with higher LDH and ?2microglobulin levels (p<0.001), lower Hb and platelet values (p<0.001), extra nodal sites (p=0.001), poor performance status (p=0.04) and relapse (p=0.001).  Conclusions:  the results suggest that HLA-G 14bp ins/del gene polymorphism is a risk factor for NHL in our Egyptian population and is associated with poor clinical pathological features.

ABBREVIATIONS

Non-Hodgkin lymphoma (NHL), Diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), Epstein-Barr virus (EBV), human T-cell lymphotropic/leukemia virus-1 (HTLV-1).

Consolidation Radiotherapy for a Rare Case of Extranodal Mucosa-Associated Lymphoid Tissue Non-Hodgkin's Lymphoma Synchronous with Prostate Adenocarcinoma

Nongastric primary extranodal mucosa-associated lymphoid tissue (MALT) lymphomas are uncommon, with around 0.1% occurring in the prostate. Even less frequent is the presence of MALT lymphoma synchronous with another type of neoplasm in the same organ, especially the prostate. Only a single case of concurrent adenocarcinoma and MALT lymphoma of the prostate has been reported in the literature. We report a rare case of primary extranodal marginal zone MALT lymphoma incidentally diagnosed during radical prostatectomy for an adenocarcinoma of the prostate in a 53-year-old patient. Fourteen months later a recurrence of the MALT lymphoma involving both sides of the diaphragm was found and was treated with chemoimmunotherapy. High-dose radiotherapy was delivered to residual bulky disease in the pelvic region. At 18 months from the end of radiation treatment the patient was without signs of relapse of MALT lymphoma. This preliminary result confirms that rare cases of MALT lymphoma of the prostate should be discussed and treated under the collaborative supervision of hematologists and medical and radiation oncologists. In fact, at an advanced stage of the disease, a chemotherapy regimen with additional consolidation radiotherapy could be an effective strategy, as in all other lymphomas.

Is There a Correlation between Helicobacter Pylori and Enterohepatic Helicobacter Species and Gallstone Cholecystitis?

BACKGROUND Cholecystitis is a common surgical condition. Recently, several authors have reported that DNA of bile tolerant Helicobacter spp. has been found in the human bile colonizing the biliary tract. The aim of this study was to evaluate the association between the presence of Helicobacter spp. and gallstone cholecystitis. METHODS In this case-control study, gallstones, bile, and gallbladder mucosa were collected from 25 patients without gallstone disease, 24 with acute cholecystitis, and 28 with chronic cholecystitis. The presence of Helicobacter pylori (H. pylori), Helicobacter bilis (H. bilis), Helicobacter hepaticus (H. hepaticus) , and Helicobacter pullorum (H. pullorum) were investigated by polymerase chain reaction (PCR) using species-specific primers. RESULTS In this study, 77 subjects with acute and chronic cholecystitis and control groups with a mean age of 46.85 ± 14.53 years, including 58 (67.25%) women and 19 (32.75%) men were included. DNA of 10 Helicobacter spp. was detected in the bile of the patients with cholecystitis including eight H. pylori and two H. bilis. However, we could not detect H. hepaticus and H. pullorum DNA in the samples. Moreover, there was an association between H. pylori and acute cholecystitis (p = 0.048), which was found to be stronger in 31-40-year-olds group (p = 0.003). CONCLUSION We found an association between the presence of H. pylori DNA and acute gallstone cholecystitis. There is not statistically significant correlation between three enterohepatic Helicobacter spp. ( H. bilis, H. hepaticus , and H. pullorum) and cholelithiasis. Given the low sample size of the patients, more studies are required to clear the clinical role of Helicobacter spp. in the gallstone disease and cholecystitis.

Characterizing antigenic determinants in Helicobacter pylori CagA capable of detecting serum antibodies in children

Helicobacter pylori can persistently colonize the mucosa of the human stomach, resulting in gastric disorders. Endoscopic biopsy for rapid urease test and histopathologic examination are considered as the most accurate diagnostic methods for H. pylori infection. Serological methods are recommended for children because of invasiveness of the diagnosis mentioned above. Here, the cytotoxin-associated gene A protein (Cag A), as an immunodominant antigen, was subdivided to determine which regions harbor antigenicity for humans. CagA was divided into 17 overlapping fragments of ∼400 bp, which were used for the analysis of antigenic determinants. The partial proteins were subjected to immunoblot analysis using pooled serum samples from children with gastric symptoms. A partial recombinant CagA protein containing epitope regions (683-749 amino acids), which were identified in this study, was produced and used for the detection of anti-CagA antibodies and further investigated its serodiagnostic value for determination of H. pylori infection in children. The serum IgG reactivities from children with gastric symptoms were significantly three times more than that of serum samples from children with non-gastric symptoms (P < 0.005). Moreover, the serum IgG reactivities from children showing strong urease activity of gastric biopsies were significantly higher than those with moderate and weak urease activities (P < 0.05). Hence, the partial CagA is a candidate antigen for diagnosis of H. pylori infection.

Primary renal lymphoma: an unusual finding following radical nephrectomy

Secondary kidney involvement by disseminated non-Hodgkin’s lymphoma (NHL) is quite common and is estimated to approach 30 – 60% in NHL patients. However, primary renal lymphoma is exceedingly rare and estimated to make up less than 1% of all kidney masses. We report a case of primary renal NHL presenting with profound hypercalcemia and renal failure recalcitrant to medical management, ultimately treated with urgent radical nephrectomy. To our knowledge, this is the first report of primary renal lymphoma presenting in this acute fashion.

Fenton reaction-induced renal carcinogenesis in Mutyh-deficient mice exhibits less chromosomal aberrations than the rat model

Oxidative stress including iron excess has been associated with carcinogenesis. The level of 8-oxoguanine, a major oxidatively modified base in DNA, is maintained very low by three distinct enzymes, encoded by OGG1, MUTYH and MTH1. Germline biallelic inactivation of MUTYH represents a familial cancer syndrome called MUTYH-associated polyposis. Here, we used Mutyh-deficient mice to evaluate renal carcinogenesis induced by ferric nitrilotriacetate (Fe-NTA). Although the C57BL/6 background is cancer-resistant, a repeated intraperitoneal administration of Fe-NTA induced a high incidence of renal cell carcinoma (RCC; 26.7%) in Mutyh-deficient mice in comparison to wild-type mice (7.1%). Fe-NTA treatment also induced renal malignant lymphoma, which did not occur without the Fe-NTA treatment in both the genotypes. Renal tumor-free survival after Fe-NTA treatment was marginally different (P = 0.157) between the two genotypes. Array-based comparative genome hybridization analyses revealed, in RCC, the loss of heterozygosity in chromosomes 4 and 12 without p16^INKA inactivation; these results were confirmed by a methylation analysis and showed no significant difference between the genotypes. Lymphomas showed a preference for genomic amplifications. Dlk1 inactivation by promoter methylation may be involved in carcinogenesis in both tumors. Fe-NTA-induced murine RCCs revealed significantly less genomic aberrations than those in rats, demonstrating a marked species difference.

Group 2 Innate Lymphoid Cells Are Involved in Skewed Type 2 Immunity of Gastric Diseases Induced by Helicobacter pylori Infection

H. pylori induces a complicated local and systematic immune response and contributes to the carcinogenesis of gastric cancer. A primary type 1 immune response is evoked by H. pylori since its occurrence. However, it is not unusual that an inhibitory immunity is dominant in H. pylori-associated diseases, which are promoted by the formation of immunosuppressive microenvironment. But whether group 2 innate lymphoid cells (ILC2s) plays a critical role in H. pylori-induced skewed type 2 immunity is still unclear. In the present study, firstly, we confirmed that type 1 immunity was inhibited and type 2 immunity were undisturbed or promoted after H. pylori infection in vitro and in vivo. Secondly, GATA-3 was firstly found to be increased in the interstitial lymphocytes from H. pylori-associated gastric cancer, among them, Lin-GATA-3⁺ cells and Lin⁺GATA-3⁺ cells were also found to be enhanced, which indicated an important role for ILC2s in H. pylori infection. More importantly, ILC2s were found to be increased after H. pylori infection in clinical patients and animal models. In conclusion, our results indicated that ILC2-mediated innate immune response might play a potential role in dominant type 2 phenotype and immunosuppressive microenvironment in H. pylori infection.

Creation and Initial Characterization of Isogenic Helicobacter pylori CagA EPIYA Variants Reveals Differential Activation of Host Cell Signaling Pathways

The polymorphic CagA toxin is associated with Helicobacter pylori-induced disease. Previous data generated using non-isogenic strains and transfection models suggest that variation surrounding the C-terminal Glu-Pro-Ile-Tyr-Ala (EPIYA) motifs as well as the number of EPIYA motifs influence disease outcome. To investigate potential CagA-mediated effects on host cell signaling, we constructed and characterized a large panel of isogenic H. pylori strains that differ primarily in the CagA EPIYA region. The number of EPIYA-C motifs or the presence of an EPIYA-D motif impacted early changes in host cell elongation; however, the degree of elongation was comparable across all strains at later time points. In contrast, the strain carrying the EPIYA-D motif induced more IL-8 secretion than any other EPIYA type, and a single EPIYA-C motif induced comparable IL-8 secretion as isolates carrying multiple EPIYA-C alleles. Similar levels of ERK1/2 activation were induced by all strains carrying a functional CagA allele. Together, our data suggest that polymorphism in the CagA C-terminus is responsible for differential alterations in some, but not all, host cell signaling pathways. Notably, our results differ from non-isogenic strain studies, thus highlighting the importance of using isogenic strains to study the role of CagA toxin polymorphism in gastric cancer development.

Fourteen-day high-dose esomeprazole, amoxicillin and metronidazole as third-line treatment for Helicobacter pylori infection

INTRODUCTION

The efficacy of currently recommended third-line therapies for Helicobacter pylori is suboptimal, even that of culture-guided treatments. Resistance to multiple antibiotics is the major factor related to treatment failure. The aim of this study was to evaluate the effectiveness and safety of a 14-day therapy using high-dose of amoxicillin, metronidazole and esomeprazole.

MATERIAL AND METHODS

Multicenter open-label study as a register in routine clinical practice in patients with two previous failures of eradication therapy. A triple therapy with esomeprazole 40 mg b.d., amoxicillin 1 g t.d.s and metronidazole 500 mg t.d.s for 2 weeks was administered as a third-line therapy after a first treatment including clarithromycin and a second treatment including a quinolone. Helicobacter pylori status was determined by either histology or ¹³ C-UBT both before and after treatment.

RESULTS

A total of 68 patients were included in this study. An interim analysis showed that only three out of eight patients who had received metronidazole in previous eradication regimens were cured (37%, 95% CI 8-75); as a result, after this interim analysis only metronidazole-naïve patients were included. The ITT eradication rate in metronidazole-naive patients was 64% (95% CI 51-76). Adverse events occurred in 58% of patients, all of them mild-to-moderate. Two patients (3%) did not complete >90% of the treatment because of side effects. No severe adverse events occurred.

CONCLUSION

Cure rates of this 14-day schedule using high-dose esomeprazole, amoxicillin and metronidazole as a third-line eradication regimen were suboptimal, especially in patients who had received metronidazole in previous failed eradication regimens.

Prevention of Gastric Cancer: Eradication of Helicobacter Pylori and Beyond

Although its prevalence is declining, gastric cancer remains a significant public health issue. The bacterium Helicobacter pylori is known to colonize the human stomach and induce chronic atrophic gastritis, intestinal metaplasia, and gastric cancer. Results using a Mongolian gerbil model revealed that H. pylori infection increased the incidence of carcinogen-induced adenocarcinoma, whereas curative treatment of H. pylori significantly lowered cancer incidence. Furthermore, some epidemiological studies have shown that eradication of H. pylori reduces the development of metachronous cancer in humans. However, other reports have warned that human cases of atrophic metaplastic gastritis are already at risk for gastric cancer development, even after eradication of these bacteria. In this article, we discuss the effectiveness of H. pylori eradication and the morphological changes that occur in gastric dysplasia/cancer lesions. We further assess the control of gastric cancer using various chemopreventive agents.

Survival of Helicobacter pylori in gastric acidic territory

BACKGROUND

Helicobacter pylori is well adapted to colonize the epithelial surface of the human gastric mucosa and can cause persistent infections. In order to infect the gastric mucosa, it has to survive in the gastric acidic pH. This organism has well developed mechanisms to neutralize the effects of acidic pH.

OBJECTIVE

This review article was designed to summarize the various functional and molecular aspects by which the bacterium can combat and survive the gastric acidic pH in order to establish the persistent infections.

METHODS

We used the keywords (acid acclimation, gastric acidic environment, H. pylori and survival) in combination or alone for pubmed search of recent scientific literatures. One hundred and forty one papers published between 1989 and 2016 were sorted out. The articles published with only abstracts, other than in English language, case reports and reviews were excluded.

RESULTS

Many literatures describing the role of several factors in acid survival were found. Recently, the role of several other factors has been claimed to participate in acid survival.

CONCLUSION

In conclusion, this organism has well characterized mechanisms for acid survival.

Reduced infectivity of waterborne viable but nonculturable Helicobacter pylori strain SS1 in mice

BACKGROUND

Helicobacter pylori infection has been consistently associated with lack of access to clean water and proper sanitation, but no studies have demonstrated that the transmission of viable but nonculturable (VBNC) H. pylori can occur from drinking contaminated water. In this study, we used a laboratory mouse model to test whether waterborne VBNCH. pylori could cause gastric infection.

MATERIALS AND METHODS

We performed five mouse experiments to assess the infectivity of VBNCH. pylori in various exposure scenarios. VBNC viability was examined using Live/Dead staining and Biolog phenotype metabolism arrays. High doses of VBNCH. pylori in water were chosen to test the "worst-case" scenario for different periods of time. One experiment also investigated the infectious capabilities of VBNC SS1 using gavage. Further, immunocompromised mice were exposed to examine infectivity among potentially vulnerable groups. After exposure, mice were euthanized and their stomachs were examined for H. pylori infection using culture and PCR methodology.

RESULTS

VBNC cells were membrane intact and retained metabolic activity. Mice exposed to VBNCH. pylori via drinking water and gavage were not infected, despite the various exposure scenarios (immunocompromised, high doses) that might have permitted infection with VBNCH. pylori. The positive controls exposed to viable, culturable H. pylori did become infected.

CONCLUSIONS

While other studies that have used viable, culturable SS1 via gavage or drinking water exposures to successfully infect mice, in our study, waterborne VBNC SS1 failed to colonize mice under all test conditions. Future studies could examine different H. pylori strains in similar exposure scenarios to compare the relative infectivity of the VBNC vs the viable, culturable state, which would help inform future risk assessments of H. pylori in water.

Infections and Follicular Lymphoma: is there a Link?

Several infectious agents appear to provide a proliferative signal -- “antigen-drive” – that could be implicated in the pathogenesis of various type of Non-Hodgkin Lymphoma (NHL). A classical model of the infection-driven lymphoproliferative disorder is Helicobacter pylori-induced gastric MALT lymphoma, where antibiotic therapy allows the eradication of both the infectious agent and the clonal B-cell expansion. Following the footsteps of this example, several retrospective studies have found a correlation with other pathogens and B-cell Lymphomas, adding new relevant information about pathogenesis and laying the groundwork for chemotherapy-free treatments.

Although no clear association has been found between infectious agents and Follicular Lymphoma (FL), a growing number of biological and clinical observations suggests the interaction of physiological and pathological microbial populations also in this subtype of lymphoma. In the last few years, epidemiological studies investigating the association of known risk factors and FL found a potential correlation with viral or bacterial infections; moreover, recent findings of the stimulation of FL clones support the importance of microbial exposure to lymphomagenesis and disease progression.

In the following review we make an attempt to find tangible evidence for a role of either physiological and pathological exogenous microbial species in the pathogenesis of FL, and try to integrate the findings coming from epidemiological, biological and interventional studies to define future novel treatment and prevention strategies for FL.

Population screening and treatment of Helicobacter pylori infection

Helicobacter pylori is an important human pathogen, associated with a substantial burden from both malignant and non-malignant diseases. The bacterium is classed as a human carcinogen, being strongly linked with gastric cancer, the third most common cause of cancer death worldwide and is also associated with common conditions such as dyspepsia and peptic ulcer. Eradication of H. pylori reduces the incidence of gastric cancer and peptic ulcer, as well as the prevalence and costs of managing dyspepsia. Economic analyses suggest that eradication of H. pylori as a means of controlling gastric cancer is cost-effective in high-risk populations. Even in populations at low risk of gastric cancer, there might be other benefits arising from screening and treatment, owing to the effects on non-malignant upper gastrointestinal diseases. However, public health authorities have been slow to consider the benefits of population-based screening and treatment as a means of reducing the morbidity and mortality associated with the infection. There are also concerns about widespread use of eradication therapy, including antimicrobial resistance and a rise in the prevalence of diseases that are negatively associated with H. pylori, such as GERD, Barrett oesophagus, asthma and obesity. This Review summarizes these issues.

An Unusual Case of Primary Extranodal Lymphoma of the Gallbladder

Primary gallbladder lymphoma is an extremely rare disease. We report a case of a 63 year-old woman who has been admitted with gradual onset abdominal pain in the upper right quadrant and in the suprapubic region, nausea and malaise. According to the computed tomography scan of the abdomen, which was suggestive of chronic cholecystitis, she was treated conservatively. A laparoscopic cholecystectomy was performed 5 months later and the histological examination of the gallbladder showed a low grade small lymphocytic lymphoma. The patient has been taken over by the hematology team who kept her under surveillance as no further treatment was deemed as necessary. The purpose of this paper is to report a rare case of primary gallbladder lymphoma and to demonstrate that a laparoscopic cholecystectomy may be a valid treatment for this disease.

Crystal structure of the type IV secretion system component CagX from Helicobacter pylori

Helicobacter pylori, a Gram-negative bacterial pathogen prevalent in the human population, is the causative agent of severe gastric diseases. An H. pylori type IV secretion (T4S) system encoded by the cytotoxin-associated gene pathogenicity island (cagPAI) is responsible for communication with host cells. As a component of the cagPAI T4S system core complex, CagX plays an important role in virulence-protein translocation into the host cells. In this work, the crystal structure of the C-terminal domain of CagX (CagXct), which is a homologue of the VirB9 protein from the VirB/D4 T4S system, is presented. CagXct is only the second three-dimensional structure to be elucidated of a VirB9-like protein. Another homologue, TraO, which is encoded on the Escherichia coli conjugative plasmid pKM101, shares only 19% sequence identity with CagXct; however, there is a remarkable similarity in tertiary structure between these two β-sandwich protein domains. Most of the residues that are conserved between CagXct and TraO are located within the protein core and appear to be responsible for the preservation of this domain fold. The studies presented here will contribute to our understanding of different bacterial T4S systems.

Targeting Bruton tyrosine kinase with ibrutinib in relapsed/refractory marginal zone lymphoma

Marginal zone lymphoma (MZL) is a heterogeneous B-cell malignancy for which no standard treatment exists. MZL is frequently linked to chronic infection, which may induce B-cell receptor (BCR) signaling, resulting in aberrant B-cell survival and proliferation. We conducted a multicenter, open-label, phase 2 study to evaluate the efficacy and safety of ibrutinib in previously treated MZL. Patients with histologically confirmed MZL of all subtypes who received ≥1 prior therapy with an anti-CD20 antibody-containing regimen were treated with 560 mg ibrutinib orally once daily until progression or unacceptable toxicity. The primary end point was independent review committee-assessed overall response rate (ORR) by 2007 International Working Group criteria. Among 63 enrolled patients, median age was 66 years (range, 30-92). Median number of prior systemic therapies was 2 (range, 1-9), and 63% received ≥1 prior chemoimmunotherapy. In 60 evaluable patients, ORR was 48% (95% confidence interval [CI], 35-62). With median follow-up of 19.4 months, median duration of response was not reached (95% CI, 16.7 to not estimable), and median progression-free survival was 14.2 months (95% CI, 8.3 to not estimable). Grade ≥3 adverse events (AEs; >5%) included anemia, pneumonia, and fatigue. Serious AEs of any grade occurred in 44%, with grade 3-4 pneumonia being the most common (8%). Rates of discontinuation and dose reductions due to AEs were 17% and 10%, respectively. Single-agent ibrutinib induced durable responses with a favorable benefit-risk profile in patients with previously treated MZL, confirming the role of BCR signaling in this malignancy. As the only approved therapy, ibrutinib provides a treatment option without chemotherapy for MZL. This study is registered at www.clinicaltrials.gov as #NCT01980628.

SNP variants associated with non-Hodgkin lymphoma (NHL) correlate with human leukocyte antigen (HLA) class II expression

Large consortia efforts and genome-wide association studies (GWASs) have linked a number of genetic variants within the 6p21 chromosomal region to non-Hodgkin lymphoma (NHL). Complementing these efforts, we genotyped previously reported SNPs in the human leukocyte antigen (HLA) class I (rs6457327) and class II (rs9271100, rs2647012 and rs10484561) regions in a total of 1,145 subjects (567 NHL cases and 578 healthy controls) from two major ethnic groups in Malaysia, the Malays and the Chinese. We identified a NHL-associated (P_{NHL_add} = 0.0008; OR_{NHL_add} = 0.54; 95% CI = 0.37–0.77) and B-cell associated (P_{Bcell_add} = 0.0007; OR_{Bcell_add} = 0.51; 95% CI = 0.35–0.76) SNP rs2647012 in the Malaysian Malays. In silico cis-eQTL analysis of rs2647012 suggests potential regulatory function of nearby HLA class II molecules. Minor allele rs2647012-T is linked to higher expression of HLA-DQB1, rendering a protective effect to NHL risk. Our findings suggest that the HLA class II region plays an important role in NHL etiology.

MicroRNAs 142-3p, miR-155 and miR-203 Are Deregulated in Gastric MALT Lymphomas Compared to Chronic Gastritis

BACKGROUND

Over the last years, our knowledge on pathogenesis of gastric MALT lymphoma has greatly improved, but its morphological diagnosis is still hampered by overlapping histological features with advanced chronic gastritis. MicroRNAs are deregulated in lymphomas, but their role and usefulness in gastric MALT lymphoma has not been extensively investigated.

MATERIALS AND METHODS

We analyzed the expression of 384 miRNAs using TaqMan microRNA assay in a training series of 10 gastric MALT lymphomas, 3 chronic gastritis and 2 reactive lymph nodes. Then, significantly deregulated miRNAs were individually assessed by real-time PCR in a validation series of 16 gastric MALT lymphomas and 12 chronic gastritis.

RESULTS

Gastric MALT lymphoma is characterized by a specific miRNA expression profile. Among the differentially expressed miRNAs, a significant overexpression of miR-142-3p and miR-155 and down-regulation of miR-203 was observed in gastric MALT lymphoma when compared to chronic gastritis.

CONCLUSION

miR-142-3p, miR-155 and miR-203 expression levels might be helpful biomarkers for the differential diagnosis between gastric MALT lymphomas and chronic gastritis.

Structure-Activity Relationship for Sulfonamide Inhibition of Helicobacter pylori α-Carbonic Anhydrase

α-Carbonic anhydrase of Helicobacter pylori (HpαCA) plays an important role in the acclimation of this oncobacterium to the acidic pH of the stomach. Sulfonamide inhibitors of HpαCA possess anti-H. pylori activity. The crystal structures of complexes of HpαCA with a family of acetazolamide-related sulfonamides have been determined. Analysis of the structures revealed that the mode of sulfonamide binding correlates well with their inhibitory activities. In addition, comparisons with the corresponding inhibitor complexes of human carbonic anhydrase II (HCAII) indicated that HpαCA possesses an additional, alternative binding site for sulfonamides that is not present in HCAII. Furthermore, the hydrophobic pocket in HCAII that stabilizes the apolar moiety of sulfonamide inhibitors is replaced with a more open, hydrophilic pocket in HpαCA. Thus, our analysis identified major structural features can be exploited in the design of selective and more potent inhibitors of HpαCA that may lead to novel antimicrobials.

The Upregulation of TRAF1 Induced by Helicobacter pylori Plays an Antiapoptotic Effect on the Infected Cells

BACKGROUND

Tumor necrosis factor receptor-associated factor 1 (TRAF1) is a member of the TRAF family and is dysregulated in diseases, such as atheroma, lymphoma, and solid tumors, but the role of TRAF1 in gastric cancer remains unknown. This study was aimed to investigate the role of TRAF1 in Helicobacter pylori (H. pylori)-related cell apoptosis and gastric carcinogenesis.

MATERIALS AND METHODS

The mRNA and protein expression levels of TRAF1 were measured in a panel of gastric cancer cell lines and in H. pylori -infected mice by quantitative real-time PCR (qPCR) and Western blotting. The transcription factor that mainly affects transcription of TRAF1 during H. pylori infection was identified. The roles of H. pylori virulence factors that regulate TRAF1 expression were analyzed using isogenic cagA-, vacA-, and cagE-null mutants. The effects of TRAF1 on gastric cell viability and apoptosis during H. pylori infection were detected using the standard MTS (cell viability) assay and flow cytometry, respectively.

RESULTS

H. pylori infection induced TRAF1 overexpression in both gastric epithelial cells and mice. The expression of TRAF1 in response to H. pylori infection was majorly regulated by the activation of NF-κB and was strongly related to H. pylori virulence factor CagA. The upregulation of TRAF1 inhibited cell apoptosis and increased the viability of infected cells.

CONCLUSIONS

H. pylori infection induces the overexpression of TRAF1 in gastric epithelial cells. The upregulation of TRAF1 plays an antiapoptotic role in H. pylori -infected gastric cells and may contribute to the gastric carcinogenesis.

Marginal zone lymphoma in elderly and geriatric patients

Approximately 50% of patients with newly diagnosed marginal zone lymphoma (MZL) are of advanced age. For the three subtypes of MZL (extranodal MZL of mucosa-associated lymphoid tissue, splenic MZL, nodal MZL), the median age at diagnosis is around 65-70 years. Due to the lack of larger studies in MZL, little is known of the prevalence of comorbidity, polypharmacy, or geriatric syndromes in older patients with MZL. The impact of these concurrent conditions on the tolerability and feasibility of diagnostic or therapeutic procedures used in MZL has not been specifically investigated. However, some extrapolations can be made from other studies in cancer, thereby raising questions about potential benefits of geriatric assessment in older patients with MZL. Core of this article is a review of recommended diagnostic and therapeutic procedures in MZL in light of potential barriers and complications that might be encountered in elderly and geriatric patients with MZL.

Idelalisib: Targeting the PI3 Kinase Pathway in Non-Hodgkin Lymphoma

Based on substantial preclinical rationale, the restricted hematopoietic expression of the δ isoform of the phosphatidylinositol 3-kinase represents an attractive therapeutic target in B-cell malignancies. Its inhibition results in a direct antiproliferative effect on tumor cells as well as several modifications of their cellular microenvironment, all accounting for the potential therapeutic interest. Idelalisib, the first-in-class phosphatidylinositol 3-kinase δ-specific inhibitor, was developed in patients with B-cell lymphomas and chronic lymphocytic leukemia. Early clinical results demonstrated a potent antitumor effect across different subtypes of indolent and mantle cell lymphomas (where response duration was short). Adverse events, including transaminitis, neutropenia, pneumonitis, and diarrhea, were observed. A pivotal phase II study in patients with double refractory disease showed a 57% response rate, with response lasting for about 1 year, leading to market approval of the drug in the United States and Europe. Further developments of idelalisib combinations will contribute to delineate the position of this drug in the therapeutic strategy of indolent lymphomas.