Regression of primary gastric lymphoma of mucosa-associated lymphoid tissue type after cure of Helicobacter pylori infection. MALT Lymphoma Study Group

Comparative gene-expression profiling of the large cell variant of gastrointestinal marginal-zone B-cell lymphoma

Gastrointestinal (g.i.) large cell lymphoma is currently regarded as diffuse large B-cell lymphoma (DLBCL) despite a more favorable clinical outcome compared to other DLBCL. Cluster analyses on a transcriptome signature of NF-κB target genes of 30 g.i. marginal zone B-cell lymphomas (MZBL; 8 g.i. MZBL, 22 large cell MZBL - among them 9 with coexisting small cell component) and 6 DLBCL (3 activated B-cell like (ABC), 3 germinal center-like (GCB)) reveals a distinct pattern. The distinctiveness of large cell MZBL samples is further confirmed by a cohort of 270 available B-cell lymphoma and B-cell in silico profiles. Of the NF-κB genes analyzed, c-REL was overexpressed in g.i. MZBL. c-REL amplification was limited to 6/22 large cell MZBL including the large cell component of 2/9 composite small cell/large cell lymphomas, and c-Rel protein expression was found in the large cell compartment of composite lymphomas. Classification experiments on DLBCL and large cell MZBL profiles support the concept that the large cell MZBL is a distinct type of B-cell lymphoma.

Non-Hodgkin lymphoma

Lymphomas can affect any organ in the body, present with a wide range of symptoms, and be seen by primary care physicians and physicians from most specialties. They are traditionally divided into Hodgkin's lymphoma (which accounts for about 10% of all lymphomas) and non-Hodgkin lymphoma, which is the topic of this Seminar. Non-Hodgkin lymphoma represents a wide spectrum of illnesses that vary from the most indolent to the most aggressive malignancies. They arise from lymphocytes that are at various stages of development, and the characteristics of the specific lymphoma subtype reflect those of the cell from which they originated. Since this topic was last reviewed in The Lancet in 2012, advances in understanding the biology and genetics of non-Hodgkin lymphoma and the availability of new diagnostic methods and therapies have improved our ability to manage patients with this disorder.

Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma of the Colon: A Case Report and a Literature Review

Patient: Female, 56

Final Diagnosis: Colonic MALT lymphoma

Symptoms: Epigastric pain

Medication: —

Clinical Procedure: Colonoscopy and biopsy

Specialty: Gastroenterology and Hepatology

Helicobacter pylori infection among non-Native educators in Alaska

OBJECTIVES

To determine seroprevalence of H. pylori infection in non-Native educators residing in urban or rural settings in Alaska, and to determine potential risk factors associated with infection in this population.

STUDY DESIGN

A cross-sectional survey of non-Native educators residing in urban or rural settings in Alaska.

METHODS

Participants completed a questionnaire detailing aspects of residential life; H. pylori antibody status was determined by a commercial assay.

RESULTS

Of the 203 non-Native participants, 49 (24%) had antibody to H. pylori. Univariate analysis demonstrated that the mean age of seropositive participants was higher than of seronegatives (48 vs. 42 years, respectively, p = .001). In addition, participants who had experienced childhood crowding were more likely to test seropositive for H. pylori (p = .058). On multivariate analysis, only age > or = 40 was associated with infection. No difference in median hemoglobin or ferritin levels were noted among seropositive and seronegative participants. There was no increased risk of seropositivity among participants who had lived in an Alaska Native village or in a developing country for > or = 6 months.

CONCLUSIONS

Overall, 24% of non-Native educators residing in rural Alaska tested positive by serology for H. pylori. Age > or = 40 years was associated with infection. Median hemoglobin or ferritin levels did not differ significantly among seropositive and seronegative participants.

Increased risk for metachronous gastric adenocarcinoma following gastric MALT lymphoma-A US population-based study

BACKGROUND

Gastric mucosa-associated lymphoid tissue lymphoma (gMALT) and gastric adenocarcinoma (GC) are long-term complications of chronic Helicobacter pylori (HP) gastritis. Treatment of HP infection induces remission in most patients with gMALT. Endoscopic follow-up is not currently endorsed after complete remission. However, the risk of GC in these patients is unclear.

OBJECTIVE

The objective of this study is to estimate GC risk in gMALT patients.

METHODS

The National Cancer Institute Surveillance, Epidemiology and End Results 13 (SEER) database-Nov 2014 Sub (1992-2012) was used to identify adult patients diagnosed with gMALT between 1992 and 2012. The standardized incidence ratio of second primary GC after a latency period of 12 months was calculated and compared to a reference SEER cohort of identical age, sex and time period. The risk of GC in these patients was also stratified by latency period (five years) and age.

RESULTS

We identified 2195 cases of gMALT lymphoma, and 20 (0.91%) of them subsequently developed GC with a relative risk (RR) of 4.32 (95% CI 2.64-6.67) compared to the American population. The median latency time was five years and the risk was maintained afterward (RR 4.92, 95% CI 2.45-8.79). When stratified by age group the risk was highest for the 45-64 group (RR 14.04, 95% CI 5.64-28.93).

CONCLUSION

gMALT lymphoma is associated with an increased risk of metachronous gastric adenocarcinoma. The risk is still present after more than five years of follow-up. Further studies may clarify the most adequate follow-up strategy.

Regression of Gastric Large B-Cell Lymphoma Accompanied by a Florid Lymphoma-like T-Cell Reaction: Immunomodulatory Effect of Ganoderma lucidum (Lingzhi)?

Complete regression of high-grade lymphoma is extremely rare. We report 1 such case that might have been conceivably mediated by Ganoderma lucidum (Lingzhi), an immunomodulatory herbal medicine. A 47-year-old man presented with epigastric pain. Endoscopy revealed a large gastric ulcer, which on biopsy was diagnostic of large B-cell lymphoma. At gastrectomy 11 days later, no evidence was found of large B-cell lymphoma despite thorough sampling. Instead, there was a dense and permeative infiltrate of CD3+ CD8+ cytotoxic small T lymphocytes spanning the whole thickness of the gastric wall. In situ reverse transcription polymerase chain reaction for T-cell receptor β-chain family did not detect a monoclonal T-cell population. We postulate that the cytotoxic T cells may represent an active host−immune response against the large B-cell lymphoma that resulted in a complete regression. On questioning, the patient had taken megadoses of Ganoderma lucidum, which might have triggered the successful immune reaction.

Long-term outcome for patients with early stage marginal zone lymphoma and mantle cell lymphoma

In this study with prolonged follow up, we compared clinical outcome, including cause of death and incidence of second cancer, for patients with early stage extranodal marginal zone lymphoma (EMZL, 49 patients), nodal marginal zone lymphoma (NMZL, nine patients) and mantle cell lymphoma (MCL, 42 patients) with emphasis on potential benefit of radiotherapy. Radiotherapy was given to 40 patients with EMZL (nine had surgery only) and all NMZL patients. MCL patients received radiotherapy (17 patients), chemotherapy followed by radiotherapy (13 patients) or chemotherapy alone (12 patients). Compared to a matched control population no increased risk of second cancer or cardiovascular disease was observed. Radiotherapy alone was effective in EMZL and NMZL with low-relapse rates (20% and 33%) and a 10-year overall survival of 78% and 56%, respectively. High-relapse rate and inferior OS in MCL underline the need for extended staging with endoscopy and PET/CT and possibly for novel strategies.

High Dose Ilaprazole/Amoxicillin as First-Line Regimen for Helicobacter pylori Infection in Korea

Objective. The eradication rate of Helicobacter pylori (H. pylori) following standard triple therapy has declined over the past few decades. This study has determined whether high dose dual therapy (PPI and amoxicillin) is adequate for eradicating H. pylori in Korea. Methods. This was an open-labeled study of H. pylori infected treatment-naive patients. Subjects received dual therapy for 14 days: ilaprazole 40 mg tablets given twice a day and amoxicillin 750 mg tablets given 4 times a day. At the end of the therapy, the subjects visited the clinic to confirm compliance and monitor for any side effects. Subjects visited again after 4–6 weeks to confirm H. pylori status through a urea breath test. Results. The cure rate of H. pylori was 79.3% (23 of 29) (95% confidence interval: 61.6–90.2) in the intention-to-treat analysis and 82.1% (23 of 28) in the per-protocol analysis. Compliance rates were high (96.6%) and side effects were minimal and tolerable. Conclusion. A high dose of ilaprazole + amoxicillin was ineffective as the first-line therapy for eradicating H. pylori in Korea. Future studies should focus on intragastric pH measurements and assess amoxicillin resistance.

Analysis of negative result in serum anti-H. pylori IgG antibody test in cases with gastric mucosal atrophy

The purpose is to elucidate factors related to negative results of anti-H. pylori antibody test in cases with gastric mucosal atrophy. A total of 859 individuals without past history of eradication therapy for H. pylori (545 males, 314 females; mean age 52.4 years) who underwent an upper GI endoscopy examination and serological test were enrolled as subjects. Serological testing was performed using SphereLight H. pylori antibody J^®, and endoscopic findings of gastric mucosal atrophy by the classification of Kimura and Takemoto and post-eradication findings were analyzed. The positive rates for the anti-H. pylori antibody test in subjects with and without gastric mucosal atrophy were 85.6% and 0.9%, respectively. In analysis of subjects with gastric mucosal atrophy, a low positive rate and serum titer was observed in subjects with C1, C2 and O3 atrophy. When the analysis was performed separately in male and female subjects, low positive rate was observed in males with O3 atrophy and females with C2 atrophy. Suspected post-eradication endoscopic findings were more frequently observed in cases with C2 atrophy. In conclusion, negative result of anti-H. pylori antibody test was frequently observed in middle-aged subjects with C1, C2 and O3 gastric mucosal atrophy.

Male Syrian Hamsters Experimentally Infected with Helicobacter spp. of the H. bilis Cluster Develop MALT-Associated Gastrointestinal Lymphomas

BACKGROUND

Aged hamsters naturally infected with novel Helicobacter spp. classified in the H. bilis cluster develop hepatobiliary lesions and typhlocolitis.

METHODS

To determine whether enterohepatic H. spp. contribute to disease, Helicobacter-free hamsters were experimentally infected with H. spp. after suppression of intestinal bacteria by tetracycline treatment of dams and pups. After antibiotic withdrawal, weanlings were gavaged with four H. bilis-like Helicobacter spp. isolated from hamsters or H. bilis ATCC 43879 isolated from human feces and compared to controls (n = 7 per group).

RESULTS

Helicobacter bilis 43879-dosed hamsters were necropsied at 33 weeks postinfection (WPI) due to the lack of detectable infection by fecal PCR; at necropsy, 5 of 7 were weakly PCR positive but lacked intestinal lesions. The remaining hamsters were maintained for ~95 WPI; chronic H. spp. infection in hamsters (6/7) was confirmed by PCR, bacterial culture, fluorescent in situ hybridization, and ELISA. Hamsters had mild-to-moderate typhlitis, and three of the male H. spp.-infected hamsters developed small intestinal lymphoma, in contrast to one control. Of the three lymphomas in H. spp.-infected hamsters, one was a focal ileal mucosa-associated lymphoid tissue (MALT) B-cell lymphoma, while the other two were multicentric small intestinal large B-cell lymphomas involving both the MALT and extra-MALT mucosal sites with lymphoepithelial lesions. The lymphoma in the control hamster was a diffuse small intestinal lymphoma with a mixed population of T and B cells.

CONCLUSIONS

Results suggest persistent H. spp. infection may augment risk for gastrointestinal MALT origin lymphomas. This model is consistent with H. pylori/heilmannii-associated MALT lymphoma in humans and could be further utilized to investigate the mechanisms of intestinal lymphoma development.

A Gain-Of-Function Mutation in the Plcg2 Gene Protects Mice from Helicobacter felis-Induced Gastric MALT Lymphoma

Gastric mucosa-associated lymphoid tissue (MALT) lymphomas develop from a chronic Helicobacter infection. Phospholipase C gamma 2 (PLCG2) is important for B-cell survival and proliferation. We used BALB/c mice with a gain-of-function mutation in the Plcg2 gene (Ali5) to analyze its role in the development of gastric MALT lymphoma. Heterozygous BALB/c Plcg2^Ali5/+ and wildtype (WT) mice were infected with Helicobacter felis (H. felis) and observed up to 16 months for development of gastric MALT lymphomas. In contrast to our initial hypothesis, Plcg2^Ali5/+ mice developed MALT lymphomas less frequently than their WT littermates after long-term infection of 16 months. Infected Plcg2^Ali5/+ mice showed downregulation of proinflammatory cytokines and decreased H. felis-specific IgG1 and IgG2a antibody responses. These results suggested a blunted immune response of Plcg2^Ali5/+ mice towards H. felis infection. Intriguingly, Plcg2^Ali5/+ mice harboured higher numbers of CD73 expressing regulatory T cells (Tregs), possibly responsible for impaired immune response towards Helicobacter infection. We suggest that Plcg2^Ali5/+ mice may be protected from developing gastric MALT lymphomas as a result of elevated Treg numbers, reduced response to H. felis and decrease of proinflammatory cytokines.

The Role of EBV in the Pathogenesis of Diffuse Large B Cell Lymphoma

Epstein-Barr virus (EBV) infection is a common feature of B cell lymphoproliferative disorders (LPDs), including diffuse large B cell lymphoma. Approximately 10 % of DLBCLs are EBV-positive, with the highest incidence in immunocompromised and elderly patients. Here, we review the clinical, genetic, and pathologic characteristics of DLBCL and discuss the molecular role of EBV in lymphoma tumorigenesis. Using EBV-positive DLBCL of the elderly as a model, we describe the key features of EBV-positive DLBCL. Studies of EBV-positive DLBCL of the elderly demonstrate that EBV-positive DLBCL has a distinct biology, related to both viral and host factors. The pathogenic mechanisms noted in EBV-positive DLBCL of the elderly, including enhanced NFκB activity, are likely to be a generalizable feature of EBV-positive DLBCL. Therefore, we review how this information might be used to target the EBV or its host response for the development of novel treatment strategies.

Concurrent gastric and pulmonary mucosa-associated lymphoid tissue lymphomas with pre-existing intrinsic chronic inflammation: a case report and a review of the literature

Herein, we report a rare case of concurrent gastric and pulmonary mucosa-associated lymphoid tissue (MALT) lymphomas. A 65-year-old man who had been diagnosed with Helicobacter pylori-positive gastric MALT lymphoma received eradication therapy and achieved complete remission. During follow-up, he developed de novo pulmonary MALT lymphoma as a sequela of pulmonary tuberculosis, accompanied by recurrent gastric MALT lymphoma. Polymerase chain reaction (PCR) products of the CDR3 region of the immunoglobulin heavy chain gene showed an overall polyclonal pattern with bands at 400 base pairs (bp) and 200 bp predominant in the pulmonary tissue, as well as two distinctive bands in the gastric tissue at 400 bp and 200 bp. This case suggests that multiorgan lymphomas are more likely to be independent from each other when they are far apart, involve different organ systems, and have independent precipitating factors.

The diagnosis and treatment of Helicobacter pylori infection in Arctic regions with a high prevalence of infection: Expert Commentary

Helicobacter pylori infection is a major cause of peptic ulcer and is also associated with chronic gastritis, mucosa-associated lymphoid tissue (MALT) lymphoma, and adenocarcinoma of the stomach. Guidelines have been developed in the United States and Europe (areas with low prevalence) for the diagnosis and management of this infection, including the recommendation to 'test and treat' those with dyspepsia. A group of international experts performed a targeted literature review and formulated an expert opinion for evidenced-based benefits and harms for screening and treatment of H. pylori in high-prevalence countries. They concluded that in Arctic countries where H. pylori prevalence exceeds 60%, treatment of persons with H. pylori infection should be limited only to instances where there is strong evidence of direct benefit in reduction of morbidity and mortality, associated peptic ulcer disease and MALT lymphoma and that the test-and-treat strategy may not be beneficial for those with dyspepsia.

Expression and clinical significance of cyclooxygenase-2 and interleukin-32 in primary gastric B-cell lymphoma

Cyclooxygenase-2 (COX-2) and interleukin-32 (IL-32) expression has been examined in various carcinomas and inflammations, and has been suggested to be significant in tumor progression and prognosis. The present study was conducted to investigate the expression of COX-2 and IL-32 in primary gastric B-cell lymphoma in order to define their clinical significance and their association with Helicobacter pylori (Hp) infection. COX-2 and IL-32 protein expression was detected in 31 primary gastric B-cell lymphoma patients and 19 chronic gastritis patients with immunohistochemistry. COX-2 and IL-32 expression was significantly higher in primary gastric lymphoma (PGL) tissues compared with gastritis tissues (51.6 vs. 21.1% for COX-2, P=0.032; and 58.1 vs. 26.3% for IL-32, P=0.029) and was significantly higher in Hp⁺ lymphoma tissues compared with Hp^- lymphoma tissues (66.7 vs. 20% for COX-2, P=0.015; and 71.4 vs. 30% for IL-32, P=0.029). In the PGL tissues, the expression level of COX-2 was positively correlated with the expression level of IL-32, and the two were each positively correlated with Hp infection (P=0.004 for COX-2 and IL-32; P=0.01 for COX-2 and Hp infection; and P=0.003 for IL-32 and Hp infection). COX-2 expression was found to be significantly associated (P<0.05) with an aggressive tumor type, higher expression of Ki-67, frequent lymph node metastasis and advanced stage. IL-32 expression was found to be significantly correlated (P<0.05) with frequent lymph node metastasis and an advanced stage. The survival time was longer in the COX-2^- and IL-32^- lymphoma patients compared with the COX-2⁺ and IL-32⁺ lymphoma patients, but these differences were not statistically significant. These results suggested that Hp infection and the expression of COX-2 and IL-32 were closely linked with each other, and that the overexpression of COX-2 and IL-32 was correlated with tumor progression in primary gastric B-cell lymphoma, thus indicating potential novel therapeutic target.

Gastric LTi cells promote lymphoid follicle formation but are limited by IRAK-M and do not alter microbial growth

Lymphoid tissue inducer (LTi) cells are activated by accessory cell IL-23, and promote lymphoid tissue genesis and antibacterial peptide production by the mucosal epithelium. We investigated the role of LTi cells in the gastric mucosa in the context of microbial infection. Mice deficient in IRAK-M, a negative regulator of TLR signaling, were investigated for increased LTi cell activity, and antibody mediated LTi cell depletion was used to analyze LTi cell dependent antimicrobial activity. H. pylori infected IRAK-M deficient mice developed increased gastric IL-17 and lymphoid follicles compared to wild type mice. LTi cells were present in naive and infected mice, with increased numbers in IRAK-M deficient mice by two weeks. Helicobacter and Candida infection of LTi cell depleted rag1(-/-) mice demonstrated LTi-dependent increases in calprotectin but not RegIII proteins. However, pathogen and commensal microbiota populations remained unchanged in the presence or absence of LTi cell function. These data demonstrate LTi cells are present in the stomach and promote lymphoid follicle formation in response to infection, but are limited by IRAK-M expression. Additionally, LTi cell mediated antimicrobial peptide production at the gastric epithelium is less efficacious at protecting against microbial pathogens than has been reported for other tissues.

The human microbiome in hematopoiesis and hematologic disorders

Humans are now understood to be in complex symbiosis with a diverse ecosystem of microbial organisms, including bacteria, viruses, and fungi. Efforts to characterize the role of these microorganisms, commonly referred as the microbiota, in human health have sought to answer the fundamental questions of what organisms are present, how are they functioning to interact with human cells, and by what mechanism are these interactions occurring. In this review, we describe recent efforts to describe the microbiota in healthy and diseased individuals, summarize the role of various molecular technologies (ranging from 16S ribosomal RNA to shotgun metagenomic sequencing) in enumerating the community structure of the microbiota, and explore known interactions between the microbiota and humans, with a focus on the microbiota's role in hematopoiesis and hematologic diseases.

Association between Helicobacter pylori infection and the subsequent risk of end-stage renal disease: a nationwide population-based cohort study

BACKGROUND & AIMS

The association between Helicobacter pylori infection and end-stage renal disease (ESRD) events remains unknown. We assessed the relationship between H. pylori infection requiring hospital admission and the subsequent risks of ESRD.

METHODS

This was a retrospective cohort study in which data from the National Health Insurance system of Taiwan was used. The H. pylori-infected cohort comprised 20,068 patients. Each participant was frequency-matched by age and sex with 4 individuals from the general population without H. pylori-infected. Cox proportional hazards regression analysis was used to estimate the influence of H. pylori infection on the risk of ESRD.

RESULTS

The overall incidence of ESRD was 3.72 times greater in the H. pylori-infected cohort than in the non-infected cohort (11.1 vs. 2.96 per 1000 person-years), with an adjusted HR of 2.58 [95% confidence interval (CI)=2.33-2.86]. The risk of ESRD markedly increased in patients with H. pylori infection combined with at least one of the following concomitant comorbidities: hypertension, diabetes, hyperlipidaemia and coronary artery disease.

CONCLUSIONS

This is currently the largest nation-based study in which the risk of ESRD in H. pylori-infected patients was examined. H. pylori infection was associated with a subsequent risk of ESRD. H. pylori-infected patients with concomitant chronic kidney disease (CKD) or cardiovascular disease (CVD) risk factors were at higher risk of ESRD than were those who had a single CKD or CVD risk factor.

Lymphocyte 'homing' and chronic inflammation

Chronic inflammation is a response to prolonged exposure to injurious stimuli that harm and destroy tissues and promote lymphocyte infiltration into inflamed sites. Following progressive accumulation of lymphocytes, the histology of inflamed tissue begins to resemble that of peripheral lymphoid organs, which can be referred to as lymphoid neogenesis or formation of tertiary lymphoid tissues. Lymphocyte recruitment to inflamed tissues is also reminiscent of lymphocyte homing to peripheral lymphoid organs. In the latter, under physiological conditions, homing receptors expressed on lymphocytes adhere to vascular addressin expressed on high endothelial venules (HEVs), initiating a lymphocyte migration process composed of sequential adhesive interactions. Intriguingly, in chronic inflammation, HEV-like vessels are induced de novo, despite the fact that the inflamed site is not originally lymphoid tissue, and these vessels contribute to lymphocyte recruitment in a manner similar to physiological lymphocyte homing. In this review, we first describe physiological lymphocyte homing mechanisms focusing on vascular addressins. We then describe HEV-like vessel-mediated pathogenesis seen in various chronic inflammatory disorders such as Helicobacter pylori gastritis, inflammatory bowel disease (IBD), autoimmune pancreatitis and sclerosing sialadenitis, as well as chronic inflammatory cell neoplasm MALT lymphoma, with reference to our work and that of others.

Intestinal microbiome and lymphoma development

The intestinal microbiota and gut immune system must communicate to maintain a balance between tolerance and activation. Our immune system protects us from pathogenic microbes at the same time that our bodies are host to trillions of microbes, symbionts, mutualists, and some that are essential to human health. Since there is such a close interaction between the immune system and the intestinal microbiota, it is not surprising that some lymphomas such as mucosal-associated lymphoid tissue lymphoma have been shown to be caused by the presence of certain bacteria. Animal models have played an important role in elucidating the causation and establishing the mechanism of bacteria-induced mucosal-associated lymphoid tissue lymphoma. In this review, we discuss different ways that animal models have been applied to investigate links between the gut microbiota and lymphoma and have helped to reveal the mechanisms of microbiota-induced lymphoma. Although there is a paucity of published studies demonstrating the interplay between the microbiota and lymphoma development, we believe that the connection is real and that it can be exploited in the future to enhance our understanding of causation and to improve the prognosis and treatment of lymphoma.

Helicobacter pylori seropositivity's association with markers of iron, 1-carbon metabolism, and antioxidant status among US adults: a structural equations modeling approach

Objectives

We tested a model in which Helicobacter pylori seropositivity (Hp_s) predicted iron status, which in turn acted as a predictor for markers of 1-C metabolism that were then allowed to predict antioxidant status.

Methods

National Health and Nutrition Examination Surveys (NHANES 1999–2000) cross-sectional data among adults aged 20–85 y were analyzed (n = 3,055). Markers of Hp_s, iron status (serum ferritin and transferrin saturation (TS)); 1-C metabolism (serum folate (FOL_serum), B-12, total homocysteine (tHcy), methylmalonic acid (MMA)) and antioxidant status (vitamins A and E) were entered into a structural equations model (SEM).

Results

Predictors of Hp_s included older age, lower education and income, racial/ethnic groups (lowest among Non-Hispanic Whites), and lifetime cigarette smoking. SEM modeling indicated that Hp_s had a direct inverse relationship with iron status (combining serum ferritin and TS) which in turn was positively related to 1-C metabolites (higher serum folate, B-12 or lower tHcy/MMA) that were positively associated with antioxidant status (combining serum vitamins A and E). Another pathway that was found bypassed 1-C metabolites (Hps → Iron_st → Antiox). The sum of all indirect effects from Hp_s combining both pathways and the other indirect pathways in the model (Hps → Iron_st → OneCarbon; Hps →OneCarbon →Antiox) was estimated at β = -0.006±0.003, p<0.05.

Conclusions

In sum, of the total effect of H. pylori seropositivity on antioxidant status, two significant indirect pathways through Iron status and 1-Carbon metabolites were found. Randomized controlled trials should be conducted to uncover the concomitant causal effect of H. pylori eradication on improving iron status, folate, B-12 and antioxidant status among H. pylori seropositive individuals.

Spontaneous perforation of primary gastric malignant lymphoma: a case report and review of the literature

BACKGROUND AND AIMS

Spontaneous gastric perforation in the absence of chemotherapy is extremely rare. The authors encountered a case of spontaneous perforation of primary gastric lymphoma.

CASE PRESENTATION

A 58-year-old man visited the authors' hospital with acute severe epigastralgia. A large amount of free gas and a fluid collection around the stomach were noted on an abdominal computed tomography scan. The results of imaging studies indicated a perforated gastric ulcer, and a distal gastrectomy was performed. There was a large perforation about 50 mm in diameter in the anterior wall of the middle part of the stomach body. Microscopically, the full thickness of the gastric wall was diffusely infiltrated by a population of large atypical lymphoid cells. The lymphoid nature of these cells was indicated by the strongly positive immunohistochemical staining for CD20 and CD10. This confirmed the diagnosis of a germinal center B-cell-like type of diffuse large B cell lymphoma. Rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone were administered after the operation.

RESULTS AND CONCLUSION

Gastrectomy should be considered if a giant ulcer with necrotic matter on the ulcer floor is seen on upper gastrointestinal endoscopy because of the possibility of gastric perforation. If upper gastrointestinal endoscopy shows a finding similar to the abovementioned one during chemotherapy, dose reduction of chemotherapy or gastrectomy should be considered.

Prospective trial in Saudi Arabia comparing the 14-day standard triple therapy with the 10-day sequential therapy for treatment of Helicobacter pylori infection

BACKGROUND/AIMS

Treatment success for Helicobacter pylori infection in Saudi Arabia is relatively unexplored. This prospective study compared the efficacy of sequential versus standard triple therapy in curing H. pylori infections.

PATIENTS AND METHODS

Eligible patients underwent upper endoscopy at a single center in Saudi Arabia from October 2011 to February 2014. Patients who tested positive for H. pylori infection were randomly assigned to sequential therapy or standard triple therapy. Sequential treatment: Esomeprazole (20 mg bid for 10 days), amoxicillin (1000 mg for 5 days), then clarithromycin 500 mg and tinidazole 500 mg; both bid for 5 days. Standard triple treatment: Esomeprazole 20 mg, clarithromycin 500 mg, and amoxicillin 1000 mg each bid for 14 days. After 6 weeks of treatment, patients were tested for cure using a validated urea breath test. Application of the E-test determined susceptibility of H. pylori to different antibiotics.

RESULTS

Of the 115 patients who received sequential therapy, 93 completed treatment. In the triple-therapy arm, 103 of 117 patients completed treatment. The eradication rate was 58/93 (62.3%) with sequential therapy and 69/102 (67.6%) with standard triple therapy, P = 0.44. Risk ratio was 0.92 (95% CI; 0.75-1.13), and number needed to treat was 19. Overall primary resistance: Metronidazole (48.5%), clarithromycin (23.3%), amoxicillin (14.8%), levofloxacin (11.1%), and tetracycline (2.3%). Mild adverse events occurred in 35 and 17 patients in the sequential and standard therapy groups, respectively.

CONCLUSION

Sequential and standard triple therapies were similarly effective at eradicating H. pylori in two-thirds of Saudi patients. Metronidazole and clarithromycin resistance to H. pylori strains was common.

Evaluation of Helicobacter pylori vacA and cagA Genotypes and Correlation With Clinical Outcome in Patients With Dyspepsia in Hamadan Province, Iran

Background:

Helicobacter pylori is known to be a causative agent of chronic active gastritis, peptic ulcer and gastric cancer in human. Diverse genotypes of H. pylori strains have different virulence potency and geographic distribution.

Objectives:

The purpose of this study was to investigate the association between the cytotoxin-associated gene (cagA), and the various vacuolating cytotoxin (vacA) genotypes of H. pylori strains and clinical outcomes in patients referred to Shahid-Beheshti Hospital in Hamadan, Iran.

Patients and Methods:

In this cross-sectional study, biopsy samples were collected consecutively from 153 patients with gastric cancer (GC), peptic ulcer dyspepsia (PUD) and non-ulcer dyspepsia (NUD) in the gastroenterology department of Shahid-Beheshti Hospital in Hamadan province, the west of Iran. H. pylori infection was confirmed in 83 patients (3 with GC, 27 with PUD, and 53 with NUD) by histology, rapid urease test (RUT) and culture. Genomic DNA was extracted from the bacterial isolate and was further confirmed with 16S rRNA gene sequencing as H. pylori, and characterized based on cagA and vacA genotyping using the polymerase chain reaction (PCR) method.

Results:

In this study, vacA genotypes s1/m2, s1/m1, s2/m2 and s2/m1 were determined in 43.4%, 19.3%, 13.2% and 6% of the isolated H. pylori, respectively. The vacAs1 genotype was detected in 52 (62.6%) isolates, of which the vacAs1a genotype was detected in 45.2, 40.7, and 66.6% of the isolates from patients with NUD, PUD, and GC, respectively. The cagA-positive genotype was determined in 73 (87.9%) isolates and 10 (12.1%) were negative. The frequency rates of cagA gene were 84.9, 92.6 and 100% in isolates of patients with NUD, PUD, and GC, respectively. The cagA-positive genotype is strongly associated with s1a/m2 and s1a/m1 vacA genotypes.

Conclusions:

The most predominant VacA genotypes in our areas were s1/m2 and s1/m1, which regard as the genotypes with more virulence intensity. The H. pylorivacAs1a, cagA genotypes have a significant relationship with the presence of PUD and GC in Iranian patients with dyspepsia.

Helicobacter pylori: perspectives and time trends

The discovery of Helicobacter pylori three decades ago is a modern medical success story. It markedly changed our understanding of the pathophysiology of gastroduodenal diseases and led to an improvement in the treatment of diseases related to H. pylori infection. Many of these diseases (such as ulcer disease and mucosal associated lymphoid tissue lymphoma) have become curable, and others (gastric cancer) might be preventable with the application of H. pylori eradication therapy. Since its discovery, H. pylori has also been identified as a trigger for some extragastric diseases. Promising results in this exciting field might have a clinical effect in the near future. This Timeline gives an overview of the success of clinical research on H. pylori to date and highlights some future trends in this area.

Diagnosis of Helicobacter pylori: What should be the gold standard?

Since the discovery of Helicobacter pylori (H. pylori) in 1983, numerous detection methods for the presence of the bacterium have been developed. Each one of them has been associated with advantages and disadvantages. Noninvasive tests such as serology, ¹³C urea breath test (UBT) and stool antigen tests are usually preferred by the clinicians. Serology has its own limitation especially in endemic areas while ¹³C UBT is technically very demanding. The stool antigen detection method, although specific, is usually associated with poor sensitivity. The ¹³C UBT is believed to be specific, but with present revelation of the fact that stomach is colonized by many other urease producing bacteria makes it questionable. Histology, culture, rapid urease test and polymerase chain reaction (PCR) are the tests which are carried out on antral biopsies collected by invasive means. Histology has been proposed to be very sensitive and specific but the question is how by simply looking the morphology of the bacteria in the microscope, one can claim that the curved bacterium is exclusively H. pylori. Rapid urease test (RUT), the doctor’s test, is also challenged because the presence of other urease producing bacteria in the stomach cannot be denied. Moreover, RUT has been reported with poor sensitivity specially, when density of the bacterium is low. Isolation of H. pylori is essential to investigate its growth requirements, antibiotic susceptibility testing, studying virulence factor to develop vaccine and many more explorations. It has also got several disadvantages i.e., special condition for transporting, media, incubation and few days waiting for the colonies to appear, apart from the speed essentially needed to process the specimens. Till date, majority of the microbiological laboratories in the world are not equipped and trained to isolate such fastidious bacterium. The option left is PCR methods to detect H. pylori’s DNA in gastric mucosa, gastric juice, saliva, dental plaques and environmental specimens. There are speculations for false positivity due to detection of non-pylori Helicobacters due to genetic sharing; and false negativity due to low bacterial counts and presence of PCR inhibitors. However, specimen collection, transportation and processing do not require speed and special conditions. PCR based diagnosis may be considered as gold standard by designing primers extremely specific to H. pylori and targeting at least more than one conserved genes. Similarly specificity of PCR may be improved by use of internal Primers. Further, nested PCR will take care of false negatives by countering the effect of PCR inhibitors and low bacterial counts. Therefore, nested PCR based methods if performed properly, may be proposed as gold standard test.

[Future trends of Helicobacter pylori eradication therapy in Korea]

The prevalence of Helicobacter pylori infection in Korea shows a decreasing trend and has changed to that of developed country, especially for those below 30 years old. However, the primary antibiotic resistance rates are higher than those of developed countries. The reason for the decrease in the efficacy of standard triple therapy is mainly due to the increase in the resistance against clarithromycin. Sequential therapy seems to be more effective than the standard triple therapy, but the intention-to-treat eradication rate of sequential therapy in Korea, which is mostly under 80.0%, is still not satisfactory. Therefore, a promising regimen is needed. Recently, the Japanese health insurance system admitted 'H. pylori-infected gastritis'as an indication of eradication. Furthermore, the Kyoto Consensus Meeting on H. pylori Gastritis held from January 30th to February 1st, 2014, proposed that 'all H. pylori positive patients should be offered to receive H. pylori eradication'. This suggests that the concept of eradication has been changed from 'treatment' to 'prevention'. Various individualized tailored therapy based on the polymorphism, age and other demographic factors and antibiotic resistance has been attempted to maximize H. pylori eradication therapy. The aim of this article is to review the current epidemiology, H. pylori resistance state, treatment guideline, and to assess the possible future strategy and treatment for H. pylori infection in Korea.

Saliva-based biosensors: noninvasive monitoring tool for clinical diagnostics

Saliva is increasingly recognised as an attractive diagnostic fluid. The presence of various disease signalling salivary biomarkers that accurately reflect normal and disease states in humans and the sampling benefits compared to blood sampling are some of the reasons for this recognition. This explains the burgeoning research field in assay developments and technological advancements for the detection of various salivary biomarkers to improve clinical diagnosis, management, and treatment. This paper reviews the significance of salivary biomarkers for clinical diagnosis and therapeutic applications, with focus on the technologies and biosensing platforms that have been reported for screening these biomarkers.

Lymphoma caused by intestinal microbiota

The intestinal microbiota and gut immune system must constantly communicate to maintain a balance between tolerance and activation: on the one hand, our immune system should protect us from pathogenic microbes and on the other hand, most of the millions of microbes in and on our body are innocuous symbionts and some can even be beneficial. Since there is such a close interaction between the immune system and the intestinal microbiota, it is not surprising that some lymphomas such as mucosal-associated lymphoid tissue (MALT) lymphoma have been shown to be caused by the presence of certain bacteria. Animal models played an important role in establishing causation and mechanism of bacteria-induced MALT lymphoma. In this review we discuss different ways that animal models have been applied to establish a link between the gut microbiota and lymphoma and how animal models have helped to elucidate mechanisms of microbiota-induced lymphoma. While there are not a plethora of studies demonstrating a connection between microbiota and lymphoma development, we believe that animal models are a system which can be exploited in the future to enhance our understanding of causation and improve prognosis and treatment of lymphoma.

[Guidelines for the diagnosis and treatment of Helicobacter pylori infection in Korea, 2013 revised edition]

Since the Korean College of Helicobacter and Upper Gastrointestinal Research has first developed the guideline for the diagnosis and treatment of Helicobacter pylori infection in 1998, the revised guideline was proposed in 2009 by the same group. Although the revised guideline was made by comprehensive review of previous articles and consensus of authoritative expert opinions, the evidence-based developmental process was not applied in the revision of the guideline. This new guideline has been revised especially in terms of changes in the indication and treatment of H. pylori infection in Korea, and developed by the adaptation process as evidence-based method; 6 guidelines were retrieved by systematic review and the Appraisal of Guidelines for Research and Evaluation (AGREE) II process, 21 statements were made with grading system and revised by modified Delphi method. After revision, 11 statements for the indication of test and treatment, 4 statements for the diagnosis and 4 statements for the treatment have been developed, respectively. The revised guideline has been reviewed by external experts before the official endorsement, and will be disseminated for usual clinical practice in Korea. Also, the scheduled update and revision of the guideline will be made periodically.

Is narrow-band imaging useful for histological evaluation of gastric mucosa-associated lymphoid tissue lymphoma after treatment?

BACKGROUND AND AIM

Endoscopic diagnosis of stomach mucosa-associated lymphoid tissue (MALT) lymphoma is often difficult because few specific findings are indicated. Even when MALT lymphoma is suspected by endoscopy, it is still difficult to make a definitive diagnosis by biopsy because lymphoma cells sometimes distribute unevenly. We previously reported that a tree-like appearance (TLA) is a characteristic finding of MALT lymphoma by narrow-band imaging (NBI) magnifying endoscopy and it is valuable in the selection of an optimal biopsy site in MALT lymphoma. Here, we study the frequency of TLA and evaluate the relationship between the response to eradication therapy and TLA in MALT lymphoma.

METHODS

We retrospectively examined the clinical background, endoscopic findings, response to eradication therapy, and Helicobacter pylori infection status of 16 patients diagnosed with MALT lymphoma who were referred to our hospital from April 2007 to August 2012. The regimen for eradicationtherapy consisted of rabeprazole, with amoxicillin and clarithromycin, all given for 7 days.

RESULTS

TLA was found in 75% (12/16) and H. pylori infection in 75% (12/16) of patients diagnosed with MALT lymphoma by NBI magnifying endoscopy. In all complete regression (CR) patients after eradication treatment, the TLA finding had disappeared (100%); however, in the non-CR patients, TLA remained the same as before the eradication therapy (P=0.002).

CONCLUSION

These results suggest that NBI magnifying endoscopy may be useful not only in the diagnosis but also in the evaluation of the response to eradication therapy of MALT lymphoma of the stomach.

Helicobacter pylori infection in gastric mucosa-associated lymphoid tissue lymphoma

Gastrointestinal lymphoma is the most common type of extranodal lymphoma, and most commonly affects the stomach. Marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) and diffuse large B-cell lymphoma are the most common histologic types of gastric lymphoma. Despite its increasing incidence, diagnosis of gastric lymphoma is difficult at an earlier stage due to its nonspecific symptoms and endoscopic findings, and, thus, a high index of suspicion, and multiple, deep, repeated biopsies at abnormally and normally appearing sites in the stomach are needed. In addition, testing for Helicobacter pylori (H. pylori) infection and endoscopic ultrasonography to determine the depth of tumor invasion and involvement of regional lymph nodes is essential for predicting response to H. pylori eradication and for assessment of disease progression. In addition, H. pylori infection and MALT lymphoma development are associated, and complete regression of low-grade MALT lymphomas after H. pylori eradication has been demonstrated. Radiotherapy and/or chemotherapy can be used in cases that show poor response to H. pylori eradication, negativity for H. pylori infection, or high-grade lymphoma.

Simultaneous occurrence of early gastric carcinoma and mucosa-associated lymphoid tissue lymphoma of the omentum

The simultaneous association of gastric carcinoma with omental mucosa-associated lymphoid tissue (MALT) lymphoma is a rare event that has not been reported previously. We focused on the hypothetic pathogenetic mechanisms, diagnosis and treatment of this rare condition. A 55-year-old woman with Helicobacter pylori infection underwent distal gastrectomy in our hospital. Three independent early gastric cancers and a mass near the cecum were diagnosed preoperatively. Pathological review of the resected stomach showed three independent early signet ring cell gastric carcinomas, and the mass in the omentum near the cecum was shown to be omental MALT lymphoma. Due to the nature of the patient's disease, she was started on medical eradication of H. pylori. Synchronous gastric adenocarcinoma and omental MALT lymphoma is a rare event. Special attention given to H. pylori-associated gastric cancer patients can avoid misdiagnosis and lead to adequate treatment.

Levofloxacin-based first-line therapy versus standard first-line therapy for Helicobacter pylori eradication: meta-analysis of randomized controlled trials

Background

First-line levofloxacin-based treatments eradicate Helicobacter pylori with varying success. We examined the efficacy and safety of first-line levofloxacin-based treatment in comparison to standard first-line therapy for H pylori eradication.

Materials and Methods

We searched literature databases from Medline, EMBASE, and the Cochrane Register of Randomized Controlled Trials through March 2013 for randomized controlled trials comparing first-line levofloxacin and standard therapy. We included randomized controlled trials conducted only on naïve H pylori infected patients in adults. A systematic review was conducted. Meta-analysis was performed with Review Manager 5.2. Treatment effect was determined by relative risk with a random or fixed model by the Mantel-Haenszel method.

Results

Seven trials were identified with 888 patients receiving 7 days of first-line levofloxacin and 894 treated with standard therapy (Amoxicillin, Clarithromycin and proton pump inhibitor) for 7 days. The overall crude eradication rate in the Levofloxacin group was 79.05% versus 81.4% in the standard group (risk ratio 0.97; 95% CI; 0.93, 1.02). The overall dropout was 46 (5.2%) in the levofloxacin group and 52 (5.8%) for standard therapy. The dizziness was more common among group who took Levofloxacin based treatment and taste disturbance was more common among group who took standard therapy. Meta-analysis of overall adverse events were similar between the two groups with a relative risk of 1.06 (95% CI 0.72, 1.57).

Conclusion

Helicobacter pylori eradication with 7 days of Levofloxacin-based first line therapy was safe and equal compared to 7 days of standard first-line therapy.

Incidence of marginal zone lymphoma in the United States, 2001-2009 with a focus on primary anatomic site

The aetiology of marginal zone lymphoma (MZL) is purported to differ by anatomic site. While this is supported by clinical series of single MZL sites, no population-based study has comprehensively assessed incidence patterns across sites. To gain insight into disease aetiology, we assessed MZL incidence by site using data from 18 U.S. Surveillance, Epidemiology and End Results (SEER) Program population-based registries. We calculated age-adjusted incidence rates (IRs) by sex, race, and calendar year. During 2001-2009, 4,081 (IR = 5·7/1,000,000 person-years) and 8,821 (IR = 12·3) individuals were diagnosed with nodal MZL and extranodal MZL, respectively. The most common extranodal sites were stomach (IR = 3·8), spleen (IR = 1·6), eye/adnexa (IR = 1·4), and lung, skin, and salivary glands (IRs = 0·9-1·0). We observed distinct age-specific patterns by MZL site, with IRs increasing steeply at younger ages and less prominently after mid-life at several sites, except skin. Gender and racial/ethnic disparities were also apparent across sites. Between 2001-2005 and 2006-2009, MZL IRs decreased significantly for gastric (-15%) and soft tissue (-28%) sites, whereas IRs increased significantly for lung (18%), skin (43%), and kidney/renal pelvis (116%). In combination, our findings support the contention that MZL is characterized by aetiological heterogeneity across sites and susceptibility is probably influenced by intrinsic characteristics and environmental exposures.

Gastric diffuse large B-cell lymphoma cured with Helicobacter pylori eradication regardless of whether it contains features of MALT lymphoma

A 66-year-old patient was diagnosed with primary gastric B-cell lymphoma. The pathological findings were consistent with diffuse large B-cell lymphoma (DLBCL); however, a small area showed features of mucosa-associated lymphoid tissue (MALT) lymphoma. Biopsy specimens were referred to two other pathologists, both of whom diagnosed the case as pure DLBCL, denying the area of MALT lymphoma. As the lymphoma was limited to the submucosal layer and the patient's general condition was excellent, eradication of Helicobacter pylori was selected as the initial treatment. The lymphoma completely disappeared three months after the eradication treatment, and complete remission has been maintained for nearly two years.

A polypoid mucosa-associated lymphoid tissue lymphoma of the stomach treated with endoscopic polypectomy

Mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach is the most common extranodal lymphoma of the gastrointestinal tract. It is usually accompanied by Helicobacter pylori infection, and eradication of H. pylori remains the mainstay of treatment for gastric MALT lymphoma. However, there is no consensus on the second-line treatment for patients with gastric MALT lymphoma who do not improve after successful H. pylori eradication. Here, we report the case of a 34-year-old woman who presented with a polypoid type of gastric MALT lymphoma on the greater curvature side of the upper body. Despite successful H. pylori eradication, the tumor did not regress after 6 months. Because the tumor had a semipedunculated polypoid morphology, gastric polypectomy was implemented as a second-line treatment. No recurrence occurred during the 3-year follow-up period. We suggest that gastric polypectomy be considered an alternative treatment modality for polypoid gastric MALT lymphoma that is unresponsive to H. pylori eradication.