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

Clinical, histological and molecular follow-up of 60 patients with gastric marginal zone lymphoma of mucosa-associated lymphoid tissue

The persistence of gastric lymphoma after Helicobacter pylori eradication may be difficult to evidence on endoscopic and histological examination. The aims of the study were to evaluate the detection of monoclonal immunoglobulin H (IgH) gene rearrangement in endoscopically infiltrated and normal mucosa at diagnosis and during follow-up in order to determine its clinical and prognostic impact. We studied 60 gastric marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT), and IgH monoclonality was detected at diagnosis in 52 patients (87%). The endoscopically normal mucosa contained clonal lymphomatous cells in 69% of cases before remission. A complete histological remission (HR) was observed in 28 patients (47%). Among them, 23 were followed for molecular remission (MR). The median delay was 10 months to achieve HR and 18 months to achieve MR. Interestingly, patients with HR but not MR had a longer delay to achieve HR (21 months) (P=0.0006) and a more frequent clonal normal mucosa at diagnosis (88%) than patients with both HR and MR (10 months and 39%, respectively). The presence of monoclonal B cells at both infiltrated and normal sites may therefore identify patients with a longer delay to achieve complete response, suggesting that molecular dissemination may require therapeutic intensification.

The relation of Helicobacter pylori to gastric adenocarcinoma and lymphoma: pathophysiology, epidemiology, screening, clinical presentation, treatment, and prevention

Helicobacter pylori infection may be the most common chronic bacterial infection worldwide; however, the prevalence varies between countries and is usually linked to socioeconomic conditions. Gastric cancer is one of the most frequent cancers in developing countries and usually about the seventh most common in developed countries. This article explores the relation of H. pylori to gastric adenocarcinoma and lymphoma. The pathophysiology, epidemiology, screening, clinical presentation, treatment, and prevention are discussed.

Sjogren’s syndrome: concomitant H. Pylori infection and possible correlation with clinical parameters

OBJECTIVE

To identify whether or not there are clinical markers that correlate with Helicobacter pylori (H. pylori) infection in patients with Sjogren's syndrome (SS) and its implication to handling this group of patients.

METHODS

Four groups of patients were studied. Group 1, 36 patients with primary SS; group 2, 31 patients with secondary SS; group 3, 46 patients with various connective tissue diseases not suffering from sicca symptoms, and group 4, 64 healthy controls. Clinical assessment was done and a score for disease manifestation was given for every SS patient. Serum IgG and IgM antibodies to H. pylori were assessed by ELISA.

RESULTS

The prevalence and mean titer of H. pylori infection in patients with SS in group 1 (80.6%) and 2 (71%) were significantly higher than in group 3 (60.9%) and 4 (56.3%) (P < 0.01). There was significant correlation between H. pylori infection and age, disease duration, global score for disease status and C-reactive protein (CRP) in SS patients. On the other hand, there was no significant correlation with body mass index, and erythrocyte sedimentation rate (ESR).

CONCLUSION

Patients with SS are more prone to have H. pylori infection in comparison to other connective tissue diseases. Serum antibody titer to H. pylori correlated with index for clinical disease manifestations, age, disease duration and CRP. Assessment of H. pylori infection in older patients suffering from active SS for a relatively long duration is recommended, especially those suffering form primary SS for more than 3 years.

Trisomy 3 may predict a poor response of gastric MALT lymphoma to Helicobacter pylori eradication therapy

AIM

To investigate the relation of the response to Helicobacter pylori eradication therapy to the depth of tumor invasion and chromosome abnormalities in patients with mucosa-associated lymphoid tissue (MALT) lymphoma and to determine the clinical value of aneuploidy.

METHODS

We studied 13 patients with localized gastric MALT lymphoma of stage E1. Before eradication therapy, the depth of tumor invasion was assessed by endoscopic ultrasonography in 8 patients and by endoscopic examination and gastrointestinal series in the remaining patients. To detect chromosomal abnormalities, paraffin-embedded tissue sections of diagnostic biopsy specimens underwent tissue-fluorescence in situ hybridization (FISH), using chromosome-specific alpha-satellite DNA probes for chromosomes 3,7,12, and 18 and YAC clones for t(11;18)(q21;q21).

RESULTS

Seven of the 13 patients had complete regression (CR) in response to H pylori eradication therapy. No patient with CR had submucosal tumor invasion. Trisomy 18 was seen in 1 patient with CR, and both trisomies 12 and 18 were present in another patient with CR. All patients with no response or progressive disease had deep submucosal tumor invasion and showed t(11;18)(q21;q21) or trisomy 3. Trisomy 7 was not detected in this series of patients.

CONCLUSION

The depth of tumor invasion is an accurate predictor of the response of stage E1 MALT lymphoma to H pylori eradication therapy and is closely associated with the presence of chromosomal abnormalities. Trisomy 3 may predict the aggressive development of MALT lymphoma.

CXCR3-positive B cells found at elevated frequency in the peripheral blood of patients with MALT lymphoma are attracted by MIG and belong to the lymphoma clone

Chemokine receptors mediate the migration of lymphocytes through binding of their ligands. CXCR3 is expressed in Th1 T cells; however, CXCR3 was recently reported in B-cell mucosa-associated lymphoid tissue (MALT)-type lymphoma and splenic marginal zone lymphoma. To investigate whether CXCR3-positive B lymphocytes in peripheral blood (PB) migrate to MALT and spleen, and whether the lymphoma clone is present in PB, we studied 16 cases of MALT lymphoma. In MALT cases, CXCR3-positive B lymphocytes in PB could migrate to MIG, the CXCR3 ligand. Immunohistochemical analysis showed that MALT lymphoma cells expressed CXCR3, whereas epithelial glands and/or stromal cells expressed MIG. In the PCR analysis for VH gene rearrangements, MALT lymphoma showed monoclonal or oligoclonal bands. In addition, in 8 of 16 MALT cases, the VH gene rearrangement of MALT lymphoma had the same bands as the CXCR3-positive B lymphocytes in PB. In 4 cases, the same clones of DNA sequences were confirmed in MALT lymphoma and CXCR3-positive B lymphocytes of PB. The findings support the theory that CXCR3-positive B lymphocytes in PB of MALT patients belong to the lymphoma clone and migrate to MIG-expressing mucosa-associated lymphoid tissue. It seemed to be associated with the dissemination of MALT lymphoma.

Gastric mucosa-associated lymphoid tissue lymphoma and Helicobacter pylori: scratch and win

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is generally associated with Helicobacter pylori infection and, in the great majority of patients, regresses after eradication. H. pylori-negative MALT lymphoma occurs in a small minority of cases in which treatment is based on surgery or chemoradiotherapy. In the search for H. pylori based on histology and the C13 urea breath test, this report describes a case with a series of false-negative results, thus confirming the possibility of a lower detectability of H. pylori in patients with MALT gastric lymphoma and supporting the use of additional tests in evaluating such pathology, including polymerase chain reaction. Additionally, treatment with CD20 monoclonal antibody (rituximab) is suggested as an alternative to surgery or treatment with chemotherapy or radiotherapy in patients with truly H. pylori-negative gastric MALT lymphoma.

Endoscopic ultrasound (EUS) in staging and follow-up of patients with malt lymphoma treated conservatively

Background: Endoscopic ultrasonography (EUS) is an important tool for diagnosis and pretreatment staging of primary gastric lymphoma. The aim of the study was to evaluate the diagnostic importance of endosonography (EUS)in gastric lymphoma; to assess the depth of tumoral infiltration in low-grade gastric lymphoma of mucosa-associated lymphoid tissue (MALT) and to assess EUS response to medical treatment (Cyclophosphamid/Mabtera and/or anti-Helicobacter pylori therapy). Methods: 26 patients with MALT gastric lymphoma were investigated by EUS. Six of them were evaluated after the eradication of Helicobacter pylori infection and 20 after and during the cyclophosphamide/Mabtera and anti H.pylori treatment. EUS staging was compared with histopathology. Tumors were staged according to the 2000 TNM and modified Ann Arbor classification. Results: Six patients were treated with anti - Helicobacter pylori eradication therapy. Full regression of lymphoma was observed in 2 of 6 (33.3%) patients, which was endoscopicaly and histologicaly proved. EUS correlated with histology in all (6/6). In 20 patients treated with cyclophosphamide/Mabtera therapy, EUS revealed regression of lymphoma in 14 cases. Positive correlation with histology was found in 11 patients (11/14; 78%). The initial EUS showed an increased wall thickness more than 5mm in 24 of 26 patients (92%). The thickening was predominantly of mucosa and submucosa and in 11 patients extended the muscularis propria. After the therapy, the gastric wall thickening returned to normal in 14 patients, however, 3 of them still had positive histology findings. In 2 cases, during the follow-up, the EUS showed remained thickening of gastric wall, whereas biopsies were negative. Six months later histology revealed progressive low-grade MALT lymphoma in this cases. Conclusion: EUS appears to be a sensitive procedure for initial staging and assessment of treatment response and long-term follow up in patients with gastric lymphoma. The importance of EUS lies in ability to detect relapse early, too.

Endoscopic ultrasound in the diagnosis, staging, and management of gastrointestinal and adjacent malignancies

Endoscopic ultrasound (EUS) is a superior modality for local staging of gastrointestinal cancer. In interventional endosonography linear array echoendoscopes permit real-time EUS-guided puncture of target lesions for cytologic evaluation of such lesions. This article describes the basic principles of EUS, established indications pertaining to gastrointestinal cancer and other malignancies, and emerging indications for this minimally invasive technology.

Induction of peripheral lymph node addressin in human gastric mucosa infected by Helicobacter pylori

Helicobacter pylori infects over half the world's population and is a leading cause of peptic ulcer and gastric cancer. H. pylori infection results in chronic inflammation of the gastric mucosa, and progression of chronic inflammation leads to glandular atrophy and intestinal metaplasia. However, how this chronic inflammation is induced or maintained is not well known. Here, we show that chronic inflammation caused by H. pylori infection is highly correlated with de novo synthesis of peripheral lymph node addressin (PNAd) presented on high-endothelial venule (HEV)-like vessels. The number of HEV-like vessels dramatically increases as chronic inflammation progresses. We found that the PNAd is bound by L-selectin.IgM chimeric protein, and decorated by NCC-ST-439 antibody, which is suggested to recognize both nonsulfated and 6-sulfated sialyl Lewis X on core 2 branched O-glycans, and MECA-79 antibody, which reacts with 6-sulfo N-acetyllactosamine on extended core 1 O-glycans. These results indicate that PNAd on HEV-like vessels present in the gastric mucosa subsequent to H. pylori infection is similar to those on HEVs present in the secondary lymphoid organs, which are essential for lymphocyte circulation. Moreover, eradication of H. pylori is associated with the disappearance of HEV-like vessels in the gastric mucosa. By contrast, very few PNAd were found in the gastric mucosa of patients with chemical gastritis caused by nonsteroidal antiinflammatory drugs. These results strongly suggest that PNAd in HEV-like vessels plays a critical role in lymphocyte recruitment during chronic inflammation induced by H. pylori infection.

Functional variability of cagA gene in Japanese isolates of Helicobacter pylori

CagA protein of Helicobacter pylori is injected into the epithelium, where CagA undergoes tyrosine phosphorylation and activates proliferation signals. However, the importance of these CagA activities for pathogenesis has yet to be resolved. The aim of this study is to analyze the genetic and functional variability of cagA gene of clinical strains in relation to gastric diseases. Thirty-six H. pylori strains were isolated from Japanese patients with various gastric diseases and examined. All 36 strains were found to contain cagA and cagE gene and to induce CagA phosphorylation upon infection. The intensity of CagA phosphorylation expressed in HeLa cells by transfection was highly correlated to the number of R1 region. The phosphorylation intensity was slightly higher in strains from chronic atrophic gastritis (CG); however, the differences were not statistically significant. These CagA proteins also activated the serum response element (SRE) reporter by 5- to 14-fold, above the level of the control. CagA proteins which lack R2 or R3 region exhibited smaller ability for SRE activation. The average of SRE activation was slightly higher in strains from cases of gastric cancer (GC; 11.4+/-1.6), MALT lymphoma (ML; 10.7+/-1.0), and chronic atrophic gastritis (CG; 11.2+/-1.6) than in those of duodenal ulcer (DU; 8.3+/-1.9) or gastric ulcer (GU; 9.0+/-1.1). In summary, most Japanese H. pylori strains contained CagA transport system and induced CagA phosphorylation, and the levels of the intensity of phosphorylation and the ability to induce SRE varied among strains. Although the association between CagA activities and disease outcome shown in this study is not very strong, variety of CagA structure, which induces variable activities, may be one of the reasons why H. pylori induces distinct diseases on host.

Comparison of E-test and disk diffusion assay to evaluate resistance of Helicobacter pylori isolates to amoxicillin, clarithromycin, metronidazole and tetracycline in Costa Rica

MIC distribution and susceptibility to four antimicrobial agents were determined by E-test for 94 Helicobacter pylori isolates from Costa Rica. Disk diffusion was evaluated as an alternative method to determine susceptibility and compared with the E-test results by linear regression analysis and an error-rate bounded method. Thirty-eight (40.4%) of the isolates were resistant to metronidazole, 5.3% to clarithromycin and 5.3% to amoxicillin. No isolate was resistant to tetracycline. Multiple resistance was found in 4.3% of the isolates. H. pylori isolates were categorised as resistant to amoxicillin, clarithromycin and tetracycline when inhibition diameters were less than 25, 21 and 25 mm, respectively, in the disk diffusion assay. A breakpoint diameter for metronidazole with disk diffusion could not be firmly established.

Effect of glycine on Helicobacter pylori in vitro

Glycine is the simplest amino acid and is used as a metabolic product in some bacteria. However, an excess of glycine inhibits the growth of many bacteria, and it is used as a nonspecific antiseptic agent due to its low level of toxicity in animals. The effect of glycine on Helicobacter pylori is not precisely known. The present study was conducted to investigate (i) the effect of glycine on clarithromycin (CLR)-resistant and -susceptible strains of H. pylori, (ii) the effect of glycine in combination with amoxicillin (AMX), and (iii) the postantibiotic effect (PAE). The MIC at which 90% of strains are inhibited for glycine was almost 2.5 mg/ml for 31 strains of H. pylori, including CLR-resistant strains. We constructed isogenic CLR-resistant mutant strains by natural transformation and investigated the difference between clinical wild-type strains and isogenic mutants. There were no differences in the MICs between CLR-resistant and -susceptible strains or between clinical wild-type and mutant strains. The combination of AMX and glycine showed synergistic activity, with the minimum bactericidal concentration of AMX with glycine decreasing to 1/10 that of AMX alone. Glycine showed no PAE against H. pylori. These results suggest that glycine may be a useful antimicrobial agent against H. pylori not only alone but also in combination with antibacterial drugs for the treatment of H. pylori-associated diseases. Glycine may represent a component of a new type of eradication therapy for CLR-resistant H. pylori.

Nuclear expression of BCL10 or nuclear factor kappa B predicts Helicobacter pylori-independent status of early-stage, high-grade gastric mucosa-associated lymphoid tissue lymphomas

PURPOSE

A high percentage of early-stage, high-grade gastric mucosa-associated lymphoid tissue (MALT) lymphomas remain Helicobacter pylori dependent. t(11;18)(q21;q21), a genetic aberration highly predictive of H. pylori-independent status in low-grade gastric MALT lymphoma, is rarely detected in its high-grade counterpart. This study examined whether nuclear expression of BCL10 or nuclear factor kappa B (NF-kappaB) is useful in predicting H. pylori-independent status in patients with stage IE high-grade gastric MALT lymphomas.

PATIENTS AND METHODS

Twenty-two patients who had participated in a prospective study of H. pylori eradication for stage IE high-grade gastric MALT lymphomas were studied. The expression of BCL10 and NF-kappaB in pretreatment paraffin-embedded lymphoma tissues was evaluated by immunohistochemistry and confocal immunofluorescence microscopy. The presence of t(11;18)(q21;q21) was identified by a multiplex reverse transcriptase polymerase chain reaction of the API2-MALT1 chimeric transcript.

RESULTS

Aberrant nuclear expression of BCL10 was detected in seven (87.5%) of eight H. pylori-independent and in none of 14 H. pylori-dependent high-grade gastric MALT lymphomas (P <.001). All seven patients with nuclear BCL10 expression had nuclear expression of NF-kappaB, compared with only two of 15 patients without nuclear BCL10 expression (P =.002). As a single variable, the frequency of nuclear expression of NF-kappaB was also significantly higher in H. pylori-independent tumors than in H. pylori-dependent tumors (seven of eight [87.5%] v two of 15 [12.3%]; P =.002). The API2-MALT1 fusion transcript was detected in only one (12.5%) of eight H. pylori-independent lymphomas.

CONCLUSION

Nuclear expression of BCL10 or NF-kappaB is highly predictive of H. pylori-independent status in high-grade gastric MALT lymphoma, and coexpression of these two markers in the nuclei is frequent.

Ongoing Monoclonal B-Cell Proliferation Is Not Common in Gastric B-Cell Lymphoma After Combined Radiochemotherapy

Purpose

Gastric marginal-zone B-cell lymphoma (MZBCL) of the mucosa-associated lymphoid tissue (MALT) is associated with chronic Helicobacter pylori gastritis. Stable complete remission (CR) can be induced by H pylori eradication. Whether this is paralleled by cure of the lymphoma remains unclear. Persisting monoclonal bands for immunoglobulin heavy chain variable region (VH) representing the lymphoma clone have been described in up to 50% of patients in CR. This retrospective study investigated whether this phenomenon also occurs after radiochemotherapy.

Patients and Methods

Biopsy samples of 20 patients receiving chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone and irradiation were analyzed before and after therapy. Study patients had Ann Arbor stage I/II primary gastric cancer, including four cases of MZBCL of MALT type, 12 cases of diffuse large-cell lymphomas (DLCL), and four cases of mixed MALT type/DLCL. Polymerase chain reaction (PCR) for VH rearrangement was performed. Monoclonal PCR products were cloned and sequenced.

Results

Fourteen of 20 patients had a monoclonal or oligoclonal band distribution at diagnosis converted into polyclonal pattern after radiochemotherapy. Of the remaining six patients, two were lost to follow-up. One patient did not respond and died of progressive disease. PCR in this patient showed persistent B-cell clonality. In three patients, the initial PCR showed a polyclonal pattern and thus could not be evaluated during follow-up.

Conclusion

In contrast with H pylori eradication alone, radiochemotherapy results in clearing of monoclonal cells during follow-up. This may result in better elimination of residual lymphoma cells. Further study is needed to determine whether this translates into lower risk of relapse.

Les lymphomes gastriques du MALT

INTRODUCTION

The stomach is the most common site involved in primary gastrointestinal lymphoma. Gastric lymphoma originates from the mucosa-associated lymphoïd tissue so called MALT. It comprises a group of distinctive clinicopathological entities which are important to consider for clinical management.

CURRENT KNOWLEDGE AND KEY POINTS

In recent years, new diagnostic tools and new treatment strategies have improved the overall prognosis. One of the most exciting recent discoveries is the hypothesis that an infection by a bacterium, Helicobacter pylori has a decisive role in gastric lymphoma.

FUTURE PROSPECTS AND PROJECTS

Recent advances, essentially due to molecular biology and cytogenetic studies may emerge with the understanding of pathogenesis and new prognostic factors of these different types of gastric lymphomas. It is the aim of our oncoming studies together with the evaluation of the new therapeutic options such as radiotherapy and monoclonal antibodies in prospective studies.

Primary Lymphoma of the Breast: A Case of Marginal Zone B-Cell Lymphoma

A case of primary marginal zone B-cell lymphoma in an elderly female patient is presented. Primary breast lymphomas are rare, comprising less than 1 per cent of all breast malignancies. These tumors have no clinical, pathologic, or radiologic pathognomonic features to distinguish them from breast adenocarcinoma. The diagnosis is usually made with an excisional biopsy, and more extensive surgery should be avoided. Delivery of radiation therapy and chemotherapy is tailored according to the histologic grade, stage of disease, and overall patient condition. This report summarizes the current knowledge reflected in the literature.

The diminishing role of surgery in the treatment of gastric lymphoma

OBJECTIVE

This article reviews the pathogenesis, diagnosis, and treatment of patients with primary gastric lymphoma, with special attention to the changing role of surgery.

SUMMARY BACKGROUND DATA

Primary gastric lymphomas are non-Hodgkin lymphomas that originate in the stomach and are divided into low-grade (or indolent) and high-grade (or aggressive) types. Low-grade lesions nearly always arise from mucosa-associated lymphoid tissue (MALT) secondary to chronic Helicobacter pylori (H. pylori) infection and disseminate slowly. High-grade lesions may arise from a low grade-MALT component or arise de novo and can spread to lymph nodes, adjacent organs and tissues, or distant sites.

METHODS

A review of the relevant English-language articles was performed on the basis of a MEDLINE search from January 1984 to August 2003.

RESULTS

About 40% of gastric lymphomas are low-grade, and nearly all these low-grade lesions are classified as MALT lymphomas. For low-grade MALT lymphomas confined to the gastric wall and without certain negative prognostic factors, H. pylori eradication is highly successful in causing lymphoma regression. More advanced low-grade lymphomas or those that do not regress with antibiotic therapy can be treated with combinations of H. pylori eradication, radiation therapy, and chemotherapy. Nearly 60% of gastric lymphomas are high-grade lesions with or without a low-grade MALT component. These lymphomas can be treated with chemotherapy and radiation therapy according to the extent of disease. Surgery for gastric lymphoma is now often reserved for patients with localized, residual disease after nonsurgical therapy or for rare patients with complications.

CONCLUSION

The treatment of gastric lymphoma continues to evolve, and surgical resection is now uncommonly a part of the initial management strategy.

Effects of fucosylated milk of goat and mouse on Helicobacter pylori binding to Lewis b antigen

AIM: To evaluate the effects of animal milk containing fucosylated antigens on Helicobacter pylori (H pylori) binding to Lewis b antigen.

METHODS: A mammary gland expression vector containing human α1-3/4-fucosyltransferase cDNA sequences was constructed. Transient expression of human α1-3/4-fucosyltransferase cDNA in goat mammary cell and establishment of transgenic mice were performed. The adhesion inhibitory properties of milk samples were analyzed by using H pylori.

RESULTS: Goat milk samples were found to inhibit bacterial binding to Lewis b antigen. The highest inhibition was observed 42 h after injection of the plasmid. The binding activity of H pylori to Lewis b antigen reduced mostly, by 83%, however milk samples from transgenic mice did not inhibit H pylori binding to Lewis b antigen.

CONCLUSION: The use of “humanized” animal milk produced by the transgenic introduction of fucosylated antigen can perhaps provide an alternative therapy and preventive measure for H pylori infection.

Primary Duodenal Low-Grade Mucosa-Associated Lymphoid Tissue Lymphoma Presenting with Outlet Obstruction

Low-grade lymphoma arising in mucosa-associated lymphoid tissue (MALT) of the duodenum represents a very rare neoplasm. We report an unusual presentation of primary duodenal MALT lymphoma in a 78-year-old man. The patient initially presented with a suspected pulmonary embolus and was anticoagulated, which precipitated a major gastrointestinal hemorrhage. A large atypical ulcer with narrowing of the duodenum beyond the bulb was seen on endoscopy. Biopsies revealed atypical lymphoid cells. Abdominal CT scan revealed a mass in either the duodenum or head of the pancreas. An endoscopic retrograde cholangiopancreatography (ERCP) was performed, which revealed a normal pancreatic duct with a large calculus in the common bile duct, which was extracted after sphincterotomy. Elective surgery was planned for suspected lymphoma of the duodenum. The patient developed severe nausea, vomiting, and fullness after meals. The patient underwent pancreaticoduodectomy for a neoplastic mass causing duodenal obstruction. Pathological examination of the resected specimen revealed a low-grade B-cell lymphoma (MALToma) arising in the duodenum and invading the pancreas. Flow cytometry confirmed the phenotype typical of MALT lymphoma. Celiac, peripancreatic, pelvic, and cervical nodes were also involved with tumor. Bone marrow was also positive for metastasis. The patient was postoperatively treated with chemotherapy for stage IV disease.

Serum antibodies to Helicobacter pylori and its heat-shock protein 60 correlate with the response of gastric mucosa-associated lymphoid tissue lymphoma to eradication of H. pylori

BACKGROUND AND AIMS

Eradication of Helicobacter pylori leads to regression of mucosa-associated lymphoid tissue (MALT) lymphomas. In this study, we measured serum antibodies to H. pylori and H. pylori-recombinant heat-shock protein 60 (rHSP60) in patients with gastric MALT lymphoma to determine whether humoral immune responses to the bacterial antigens correlate with the efficacy of eradication therapy.

METHODS

Serum samples were obtained from 33 patients with H. pylori-positive gastric MALT lymphoma before undergoing therapy to eradicate the bacteria. Anti-H. pylori antibodies were measured in a commercial assay and in immunoassays to lysates and rHSP60 which were prepared from ATCC 43504 strain.

RESULTS

Helicobacter pylori were eradicated in all 33 patients, and the lymphoma completely regressed histologically in 26 patients (79%). Pre-treatment titers of serum antibody to H. pylori and to rHSP60 in the patients whose tumor regressed were significantly higher than titers in patients whose tumors did not regress (p =.0011 and.035, respectively). By logistic regression analysis, age (odds ratio = 0.88, 95% confidence interval = 0.80-0.99), endoscopic appearance (0.053, 0.004-0.65), titers of anti-H. pylori antibodies (67.6, 2.5-1800), and titers of anti-rHSP60 antibody (6.4, 1.2-36) were identified as significantly associated factors with the outcome of MALT lymphoma.

CONCLUSIONS

Measurement of serum antibodies to H. pylori and HSP60 might be useful for predicting the response of gastric MALT lymphoma to eradication of H. pylori.

Fludarabine-containing chemotherapy as frontline treatment of nongastrointestinal mucosa-associated lymphoid tissue lymphoma

BACKGROUND

Mucosa-associated lymphoid tissue (MALT) lymphoma is a specific clinicopathologic entity with gastric and nongastrointestinal site involvement. The authors reported the clinical outcome of patients with Stage IE nongastrointestinal MALT lymphoma treated with a frontline fludarabine-containing regimen or with a regimen containing cyclophosphamide, vincristine, and prednisone (CVP).

METHODS

Between 1998 and 2001, 31 patients with Stage IE disease were referred to the Seràgnoli Institute of Hematology and Medical Oncology at the University of Bologna (Bologna, Italy). Presenting sites included periorbital soft tissue (n = 8), lung (n = 5), skin (n = 5), salivary glands (n = 5), lacrimal glands (n = 5), and thyroid (n = 3). Twenty patients were treated with fludarabine and mitoxantrone (FM), and 11 were treated with the CVP regimen. The median follow-up was 3 years.

RESULTS

All patients achieved complete responses (CR). Four patients, all treated with CVP, experienced disease recurrence and then achieved a second CR after FM salvage treatment. No tumor recurrence was observed in patients with thyroid, lacrimal gland, or pulmonary lymphoma. The projected 5-year overall survival and disease-free survival rates were 100% and 85%, respectively.

CONCLUSIONS

The fludarabine-containing FM regimen provided a relatively effective frontline (or salvage) treatment option for patients with nongastrointestinal Stage IE MALT lymphoma and probably was superior to CVP in terms of efficacy.

Evidence for an association between Chlamydia psittaci and ocular adnexal lymphomas

BACKGROUND

Ocular adnexal lymphomas may be antigen-driven disorders; however, the source of the putative antigen or antigens is still unknown. Hence, we assessed whether Chlamydiae infection is associated with the development of ocular adnexal lymphomas.

METHODS

The presence of Chlamydia psittaci, trachomatis, and pneumoniae DNA was investigated by polymerase chain reaction in 40 ocular adnexal lymphoma samples, 20 nonneoplastic orbital biopsies, 26 reactive lymphadenopathy samples, and peripheral blood mononuclear cells (PBMCs) from 21 lymphoma patients and 38 healthy individuals. Seven patients with chlamydia-positive PBMCs were treated with the antibiotic doxycycline, and objective response was assessed in four patients with measurable lymphoma lesions. Differences in Chlamydiae DNA detection between the case patients and the control subjects were analyzed using the Fisher exact test. All statistical tests were two-sided.

RESULTS

Thirty-two of the 40 (80%) ocular adnexal lymphoma samples carried C. psittaci DNA, whereas all lymphoma samples were negative for C. trachomatis and C. pneumoniae. In contrast, none of the 20 nonneoplastic orbital biopsies (0% versus 80%; P<.001) and only three of 26 (12%) reactive lymphadenopathy samples (12% versus 80%; P<.001) carried the C. psittaci DNA. Nine of 21 (43%) patients with chlamydia-positive lymphomas carried C. psittaci DNA in their PBMCs, whereas none (0%) of the healthy PBMC donors carried C. psittaci DNA in their PBMCs (43% versus 0%; P<.001). One month after doxycycline treatment, chlamydial DNA was no longer detectable in the PBMCs of all seven treated patients, and objective response was observed in two of the four evaluable patients.

CONCLUSION

Patients with ocular adnexal lymphoma had a high prevalence of C. psittaci infection in both tumor tissue and PBMCs. Persistent C. psittaci infection may contribute to the development of these lymphomas, as was also supported by the clinical responses observed in this study with C. psittaci-eradicating antibiotic therapy.

[Primary gastric lymphoma]

Primary gastric lymphoma derives from a secondary MALT system developing after a reaction of the immune system, e.g. following chronic gastritis induced by Helicobacter pylori. Morphologically, follicular hyperplasia is found in the gastric mucosa. The pathoetiologic model confirms the transformation of a malignant lymphoma from low grade to high grade by demonstrating increasing autonomous proliferation and, finally, uncontrolled dissemination. Modern diagnostic tools are essential for staging and planning an adequate therapeutic strategy. At present, the therapeutic strategies regarding primary lymphoma are under discussion. Nevertheless, the consensus of international medical and surgical associations still recommends surgical therapy with curative intention for low-grade malignant lymphomas staged I 2-II 2. In cases of high-grade malignant lymphoma, conservative therapy is supposed to be similarly successful. The recent success of noninvasive therapeutic concepts seems to justify the application of triple eradication medication in case of Hp infection as well as radio- and chemotherapy in low- and high-grade malignant lymphomas. However, in cases of nonremission or therapy-associated complications such as uncontrollable bleeding or tumor perforation, surgery is the only therapeutic option. Regarding the oncological aspects of lymphoma growth, surgery should then be performed in order to achieve R0 resection.

Marginal Zone B-cell Lymphoma (MALT Lymphoma)

The preferred terminology for mucosa-associated lymphoid tissue (MALT) lymphoma of the stomach (variously referred to as MALT lymphoma, MALToma, low-grade MALToma, or pseudolymphoma) is marginal zone B-cell lymphoma (MZBL). MZBL, the hallmark of which is the lymphoepithelial lesion, develops as a consequence of Helicobacter pylori infection in susceptible individuals. In general, MZBL is slow growing, can remain localized for years, and has an excellent prognosis. Staging involves endoscopy with biopsy, computed tomography scanning, and endoscopic ultrasound. In patients with limited disease, eradication of H. pylori leads to remission. In patients who fail eradication therapy or have more extensive disease, surgery, chemotherapy, and radiation alone and in various combinations have been used successfully.

Are tonsils a reservoir for Helicobacter pylori infection in children?

OBJECTIVE

Helicobacter pylori (H. Pylori) has been associated with the development of gastritis, peptic ulcer and gastric cancer. Although H. pylori infects up to more than half of the world's population, to date the precise modes of transmission has not been fully understood yet. Therefore a study was planned to investigate whether the tonsils and the adenoid tissue were the reservoir or the gate for the entrance of H. pylori.

METHODS

The adenotonsillectomy specimens obtained from 50 children, between two and 10 years of age were examined for H. Pylori colonization by the CLO-test method. Before tonsillectomy, anti-H. pylori IgG antibody titers were detected by commercial enzyme immunoassay method in venous blood and H. pylori antigen enzyme immunoassay for detection of H. pylori in stool was used to define current infection status.

RESULTS

The stool antigen was positive in 25 (50%) of 50 children. Serum IgG antibody was positive in 28 (56%) patients and both tests were positive in 21 (42%) patients. H. pylori positivity was not detected in any one of the adenotonsillectomy specimens with the CLO-test method.

CONCLUSION

In this study although H. pylori was detected in stools of children, it was not detected in adenotonsillectomy specimens with CLO-test method. The results may indicate that H. pylori does not colonize in either adenoid or tonsils and that these tissues do not constitute a reservoir for H. pylori infection.

Evaluation of the association of nine Helicobacter pylori virulence factors with strains involved in low-grade gastric mucosa-associated lymphoid tissue lymphoma

Helicobacter pylori has been associated with the development of two malignant diseases: gastric adenocarcinoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Although the cag pathogenicity island, especially the cagA gene, has been linked with adenocarcinoma, few data concerning H. pylori pathogenic factors involved in low-grade gastric MALT lymphoma are available. The goal of this study was to analyze the prevalence of and correlation between genes coding for seven H. pylori virulence factors (cagA, cagE, vacA, iceA, babA, hopQ, and oipA) and two novel adhesins (sabA and hopZ) by comparing a collection of 43 H. pylori strains isolated from patients with low-grade gastric MALT lymphoma to 39 strains isolated from age-matched patients with gastritis only. Our results show that taken individually, none of the nine genes tested can be considered associated with MALT strains and allow us to conclude that MALT pathogenesis is not linked with more proinflammatory H. pylori strains. We demonstrated that in patients infected with strains harboring the iceA1 allele, sabA functional status, and hopZ "off" status, the odds of developing a MALT lymphoma were 10 times higher. However, the low prevalence of such strains (10 of 43 MALT strains) renders this triple association a low-sensitivity marker for MALT strains. Our data confirmed that H. pylori virulence factors are correlated with one another. If the involvement of H. pylori in MALT lymphoma is well established, the pathomechanism by which gastric lymphoma occurs remains to be identified.

Immune response in Helicobacter pylori-induced low-grade gastric-mucosa-associated lymphoid tissue (MALT) lymphoma

We have reported previously that heat-shock protein 60 kDa (hsp60) of Helicobacter pylori is an important antigen in the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. In order to investigate associations with host immune reactions and hsp60 antigen, CD40 ligand (CD40L) expression and cytokine production were analysed following stimulation with hsp60. To provide a clear antigen-driven immune response, peripheral blood mononuclear cells (PBMC) from patients with low-grade MALT lymphoma and gastritis and those from healthy volunteers were stimulated with recombinant H. pylori hsp60 and H. pylori cell lysate in the presence of cytokines (IL4 and granulocyte-macrophage colony-stimulating factor). mRNA expression was also analysed by a cDNA microarray containing 1100 genes. Expression of CD40L on PBMCs of patients with MALT lymphoma was increased by cytokines or by combination with stimulation with hsp60 antigens. The production of IL4 in PBMC cultures was increased in patients with MALT lymphoma; however, production of IFN-gamma was at low levels. DNA microarray analysis indicated increased levels of HLA-DR and integrin mRNAs. In cases of low-grade MALT lymphoma, adaptive immune responses against hsp60 may be enhanced by host factors, such as antigen presentation and T-cell activation, resulting in B-cell proliferation, which can be demonstrated during chronic H. pylori infection.

Localized mucosa-associated lymphoid tissue lymphoma treated with radiation therapy has excellent clinical outcome

PURPOSE

Extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) is a distinct lymphoma with unique clinicopathologic features. We report the clinical outcome of stage I and II MALT lymphoma treated with involved field radiation therapy (RT).

PATIENTS AND METHODS

From 1989 to 2000, 103 patients with stage IE and IIE disease were referred. Their median age was 60 years, with a 2:1 female predominance. Presenting sites were stomach (17 patients), orbital adnexa (31 patients), salivary glands (24 patients), thyroid gland (13 patients), and other sites (18 patients). Ninety-three patients received RT--85 received RT alone, and eight received chemotherapy and RT--with a median dose of 30 Gy. The median follow-up time was 5.1 years.

RESULTS

A complete response (CR) to RT alone was achieved in 84 of 85 patients. Among CR patients, 14 experienced relapse. Relapse sites were mostly contralateral paired-organ or distant MALT locations and, infrequently, lymph nodes. The crude local control rate with RT was 95.3% (81 of 85 patients). No relapses were observed in patients with stomach or thyroid lymphoma, whereas 14 of 63 patients (22%) experienced relapse in the other sites. The overall 5-year survival rate was 98%, and the disease-free survival rate was 77%. Transformed lymphoma was observed in 14% of patients (two of 14) experiencing relapse.

CONCLUSION

Moderate-dose RT achieved excellent local control in localized MALT lymphomas and had curative potential for three fourths of the patients. Gastric and thyroid MALT lymphomas had better outcome, whereas distant failures were common for other sites. Despite relapse, the disease often maintained an indolent course.

A prospective, randomized study of quadruple therapy and high-dose dual therapy for treatment of Helicobacter pylori resistant to both metronidazole and clarithromycin

BACKGROUND AND AIM

Failure of primary anti-H. pylori therapy results in a high rate of antimicrobial resistance. Here, we investigated the efficacy of high-dose dual therapy and quadruple therapy as salvage treatments for eradication of H. pylori resistant to both metronidazole and clarithromycin.

PATIENTS AND METHODS

Patients with at least one treatment failure and infected with H. pylori resistant to both metronidazole and clarithromycin, were randomized to receive either omeprazole 4 x 40 mg and amoxicillin 4 x 750 mg; or omeprazole 2 x 20 mg, bismuthcitrate 4 x 107 mg, metronidazole 4 x 500 mg and tetracycline 4 x 500 mg. Both regimens were given for 14 days. In cases of persistent infection, a cross-over therapy was performed.

RESULTS

Eighty-four patients were randomized. Cure of H. pylori infection was achieved in 31 patients after dual therapy and in 35 patients after quadruple therapy (per protocol: 83.8% (95% CI, 67.9-93.8) and 92.1% (95% CI, 78.6-98.3), respectively (p=0.71); intention to treat: 75.6% (95% CI: 59.7-87.6) and 81.4% (95% CI: 66.6-91.6), respectively (p=0.60)). Cross-over therapy was performed in six of nine patients, four of whom were cured of the infection.

CONCLUSION

Both high-dose dual therapy and quadruple therapy are effective in curing H. pylori infection resistant to both metronidazole and clarithromycin in patients who experienced previous treatment failures.

Treatment of Helicobacter pylori infection using a novel antiadhesion compound (3'sialyllactose sodium salt). A double blind, placebo-controlled clinical study

BACKGROUND AND AIM

3' sialyllactose sodium salt (3'SL) is an oligosaccharide that occurs naturally in human and bovine milk. It can inhibit the adhesion of H. pylori to human epithelial cells in vitro. The aim of this study was to test whether this oligosaccharide can suppress or cure H. pylori colonization in vivo and to determine its safety in humans.

METHODS

Seventy-one consecutive dyspeptic patients with H. pylori infection documented by histology and 13C-Urea Breath Test (UBT) were initially recruited to this study. Patients with UBT values <15 were excluded, thus reducing the enrollment to 65 patients. They were given two different dosages of 3'SL (10 g or 20 g/day) in three daily administrations before meals or placebo for 4 weeks, according to a randomised double-blind protocol. A standardized 13C-UBT (using 100 mg of 13C labelled urea) was repeated in all patients at fixed intervals during treatment (at the end of weeks 1, 2 and 4) and 4 weeks after treatment withdrawal. Patients compliance and side-effects were evaluated at each weekly visit.

RESULTS

Five patients were excluded from the PP analysis due to violation of the protocol (noncompliance, lost to follow-up), whereas 61 patients completed correctly the study: 17 received 3'SL 10 g/day, 22 were treated with 3'SL 20 g/day and 21 were given placebo. The three treatment groups did not significantly differ in demographic or clinical patient characteristics. No serious adverse events were observed during therapy in any of the three groups. No patients became UBT negative (<4) during or after treatment but UBT values decreased significantly during the study period in both treatment groups and placebo.

CONCLUSIONS

Antiadhesive therapy was safe and well tolerated but did not suppress or cure H. pylori colonization in humans. The observed decrease in UBT values could be explained by a regression towards the mean effect.

MALT Lymphomas

Mucosa-associated lymphoid tissue (MALT) lymphomas occur in a variety of organs, including the orbit, conjunctiva, salivary glands, skin, thyroid gland, lungs, stomach, and intestine. These tumors are often localized and of indolent clinical behavior. Diagnosis is made by pathologic evaluation of a tissue biopsy. Careful staging is mandatory and tailored to the initial presentation. Staging includes a history and physical, chemistries, computed tomography scan, and bone marrow biopsy. This information is supplemented with an ear, nose, and throat consultation, esophagogastro-duodenoscopy, colonoscopy, endoscopic ultrasound of the stomach, and cytogenetic/immunohistochemical analysis of the tumors. Treatment is tailored to organ involvement and stage at presentation. Eradication of Helicobacter pylori using a triple anti-H. pylori regimen approved by the US Food and Drug Administration is standard therapy for all H. pylori-positive gastric MALT lymphomas. Endoscopic ultrasound- and computed tomography-staged gastric MALT stage IE tumors will achieve a complete response with this approach in approximately 60% to 90% of patients (the more superficial the tumor, the better the response). Patients with tumors that are T4 node-positive Musshoff stage IIE1 and IIE2 or tumors with adverse cytogenetics should receive radiotherapy or surgery with or without radiotherapy. Tumors with a significant high-grade component or large cell tumors with a minor low-grade MALT component should receive CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone)-based chemotherapy. Localized MALT lymphomas of the orbit, conjunctiva, salivary glands, and thyroid gland are treated successfully with radiotherapy. Surgery as first-line therapy for gastric MALT lymphomas was replaced by attempts at organ preservation. In the past, margin-free surgical excision or tumor debulking followed by radiation therapy and chemotherapy has been highly effective for gastric MALT lymphomas. Therefore, surgical excision of large cell or bulky tumors of the stomach, thyroid, lung, and salivary gland, followed by adjuvant radiotherapy or chemotherapy, may still be an important consideration in selected patients. Surgery still has a role for patients with relapsed or refractory low-grade disease and life-threatening hemorrhage. Disseminated MALT lymphomas are incurable and are treated primarily with chemotherapy according to symptoms.

Burden of Helicobacter pylori and H. pylori-related diseases in developed countries: recent developments and future implications

Helicobacter pylori colonizes the gastric mucosa. H. pylori infection is the main cause of peptic ulcer and gastric malignancy. This review gives an overview on the epidemiology of H. pylori infection and H. pylori-associated diseases in the developed world, mainly Europe, and it discusses very recent developments with regard to the prevalence and its future implications for H. pylori-associated diseases.

Endoscopic ultrasonography for assessment of medical treatment in patients with gastric mucosa‐associated lymphoid tissue lymphoma

Background:  Although gastric mucosa‐associated lymphoid tissue (MALT) lymphoma often regresses after medical treatment, it is not known whether submucosal lymphomatous involvement persists. Because sampling error is a problem associated with histological evaluation and endoscopic ultrasonography (EUS) is appropriate for assessing the depth of infiltration in cases of gastric lymphoma, we investigated the value of EUS for assessing the effectiveness of medical treatment.

Methods:   Twelve patients with gastric MALT lymphoma were treated with Helicobacter pylori eradication therapy and/or chemotherapy. Endoscopic ultrasonography was done at initial staging and after treatment. We used EUS to measure the distance from the surface layer to the deepest part of the hypoechoic area; a distance of less than 1.3 mm was considered normal.

Results:   The mean depth of the hypoechoic area in MALT lymphoma‐positive biopsy specimens was significantly greater than that in MALT lymphoma‐negative biopsy specimens. In many cases in which MALT lymphoma disappeared after treatment, the depth of the endoscopic ultrasonographic hypoechoic area also decreased to normal. In two cases, however, in which the MALT lymphoma biopsy results were negative but there was no decrease to normal depth, recurrence occurred during follow up.

Conclusion:  Our results show that measurement of the depth of the hypoechoic area via EUS is useful in assessing the response of gastric MALT lymphoma to treatment. When the depth of the hypoechoic area does not decrease to normal, careful follow up and frequent biopsies are required.

Long-term observation of reflux oesophagitis developing after Helicobacter pylori eradication therapy

BACKGROUND

Development of reflux oesophagitis after Helicobacter pylori eradication therapy has been reported, but the prognosis is not well known.

AIM

To evaluate the prognosis of patients with reflux oesophagitis that developed after eradication therapy by long-term observation.

METHODS

Forty-five patients who developed reflux oesophagitis after successful H. pylori eradication therapy were followed up prospectively. All 45 patients were followed up by endoscopy more than 3 years after onset of reflux oesophagitis (3-year follow-up group) and nine were followed up more than 5 years after onset (5-year follow-up group). Endoscopic observations were performed yearly or when upper gastrointestinal symptoms recurred. Reflux oesophagitis was graded according to the Los Angeles Classification System. Presence of gastro-oesophageal reflux symptoms and medication of proton pump inhibitors, H2-blockers or prokinetics were investigated at final endoscopy.

RESULTS

All patients were classified as grade A or B at initial endoscopy. At final observation, the grade of reflux oesophagitis improved in 35/45 (78.8%) patients from the 3-year follow-up group and 7/9 (78.8%) patients from the 5-year follow-up group. Reflux oesophagitis progressed from grade A to B in only four (8.9%) patients from the 3-year follow-up group and in no patients in the 5-year follow-up group. No patient progressed to grade C or D. Gastro-oesophageal reflux symptoms were seen in 12 patients (26.7%) from the 3-year follow-up group and four patients (44.4%) from the 5-year follow-up group. Among them, medication was needed continuously in only six (13.3%) and two (22.2%) patients, respectively.

CONCLUSIONS

Reflux oesophagitis, which develops after H. pylori eradication therapy, rarely becomes a long-term clinical problem among patients who complete therapy successfully.

Delta (13)C-urea breath test value is a useful indicator for Helicobacter pylori eradication in patients with functional dyspepsia

BACKGROUND

Eradication of Helicobacter pylori is not routinely recommended for the symptomatic relief and the prevention of gastric cancer in patients with functional dyspepsia. The present study investigated a useful indicator of H. pylori eradication in such patients by determining the optimal cutoff value of a 13C-urea breath test (UBT).

METHODS

One hundred dyspeptic patients participated in the study. Dyspepsia was scored, and a 13C-UBT administered. A level of delta 13C-UBT of>4 per thousand was diagnosed as H. pylori-positive. After the stomach was endoscopically sprayed with phenol red, biopsy specimens were taken from the antrum, body and cardia of the stomach for the assessment of H. pylori density, and activity (neutrophil infiltration) and degree (lymphocyte infiltration) of gastritis.

RESULTS

Correlation between delta 13C-UBT and dyspepsia score was not found. Delta 13C-UBT significantly correlated with H. pylori density score in the total stomach (r = 0.53, P < 0.0001), neutrophil (r = 0.34, P = 0.0005) and lymphocyte score (r = 0.69, P < 0.0001). Twenty-six of the 100 subjects had a neutrophil score of >or=4, lymphocyte score of >or=4, and H. pylori score of >or=4. Their 95% confidence interval of mean was 58.2 per thousand, which reflects moderate to marked acute and chronic gastritis, and dense H. pylori colonization.

CONCLUSIONS

The 13C-UBT is a reliable semiquantitative test to assess H. pylori density and the activity and degree of gastritis. It is proposed that H. pylori eradication therapy might be beneficial for patients with functional dyspepsia with a delta 13C-UBT of >58.2 per thousand.

Review article: the treatment of refractory Helicobacter pylori infection

The occurrence of refractory Helicobacter pylori infection is increasing. When the bacteria are not eradicated it means that the antibiotics have not reached the gastric mucosa at a sufficient concentration and over a sufficient time lapse to kill them. The main reasons for this are poor patient compliance, resistant bacteria, low gastric pH and a high bacterial load. Therefore, when administering a new treatment, it is important to choose antibiotics which do not face resistance problems and which increase the dosage of antisecretory drugs and the duration of treatment and, if possible, to add a topical agent such as bismuth salt. The recommended empirical strategy is to prescribe quadruple therapy or, alternatively, 2-week triple therapy including amoxicillin-metronidazole, tetracycline-metronidazole or amoxicillin-rifabutin. However, when H. pylori is susceptible, clarithromycin can still be used. In the case of a high level of metronidazole resistance, furazolidone can be employed. In each case, it is important to ensure good patient compliance, and counselling is helpful in this regard. However, the best approach remains the prevention of refractory H. pylori infection and, for this purpose, antimicrobial susceptibility testing before first-line therapy is important and should be encouraged.

Helicobacter pylori: an invading microorganism? A review

In this review we evaluate the pros and cons of Helicobacter pylori invasion of epithelial cells as part of the natural history of H. pylori infection. H. pylori is generally considered an extracellular microorganism. However, a growing body of evidence supports the controversial hypothesis that at least a subset of H. pylori microorganisms has an intracellular (intraepithelial) location. Most significant is the fact that H. pylori invades cultured epithelial cells with invasion frequencies similar to Yersinia enterocolitica and better than Shigella flexneri; furthermore, studies of invasion mechanisms suggest that H. pylori invasion of and survival within epithelial cells is not merely a passive event, but requires active participation of the microorganism. Although many studies of human gastric biopsy specimens have failed to demonstrate any intracellular H. pylori, some studies have revealed a minor fraction of H. pylori inside gastric epithelial cells, with possible linkage to peptic ulceration and epithelial cell damage. In conclusion, these data encourage further research to establish whether intracellular H. pylori does play a role in H. pylori colonization of the human stomach and in peptic ulcer pathogenesis.

MALT lymphoma at the base of the tongue developing without any background of immunodeficiency or autoimmune disease

We report a very rare case of a mucosa-associated lymphoid tissue (MALT) lymphoma of the base of the tongue. A 61-year-old woman was admitted to our hospital for further examination of a 12 mm x 15 mm x 5 mm tongue tumor. Histological examination of the tumor revealed a marked lymphoepithelial lesion. Lymphoma cells expressed CD5(-), CD10(-), CD19(+), CD20(+) on the surface of the cells by fluorescence activated cell sorter, and the genotypic analysis of the tumor cells revealed the presence of immunoglobulin heavy chain rearrangement and the absence of BCL-2 gene rearrangement by southern blot hybridization. Furthermore, neither the t(11;18) (q21;q21) translocation nor trisomy 3 was detected in lymphoma cells by fluorescence in situ hybridization method. The tongue tumor was completely resected and no recurrence has been noted in the 13 months to date.

Helicobacter pylori babA2, cagA, and s1 vacA genes work synergistically in causing intestinal metaplasia

AIMS

To determine any associations between the Helicobacter pylori genes babA2, oipA, cagA and the s and m alleles of vacA. In addition, to verify whether these genes work synergistically or independently in causing gastritis, peptic ulcer, and intestinal metaplasia.

METHODS

One hundred and sixty seven H pylori positive patients were studied (52 antral gastritis, 41 diffuse gastritis, 41 peptic ulcer, and 33 duodenitis). Helicobacter pylori virulence genes were amplified by means of the polymerase chain reaction.

RESULTS

Significant associations were found between babA2 and the other H pylori genes studied. When considered singly, all the genes were associated with disease diagnosis, inflammation, and intestinal metaplasia. Four H pylori groups were defined. Group A: cagA-, s2m2, babA2-; group B: cagA+, s1m1, babA2+; group C: cagA+, s1m2, babA2+; group D: cagA+, s1m2, babA2-. Group A infecting strains were associated with less severe endoscopic and inflammatory conditions, whereas group B strains were associated with the worst endoscopic and inflammatory findings. Intestinal metaplasia was a rare finding in group A infected patients (< 10%), whereas it was frequent in those infected with group B strains (48%).

CONCLUSIONS

The H pylori genes cagA, oipA "on", s1 and m1 vacA, and babA2 are associated with each other, possibly as a result of shared selective pressure. When coexpressed by the same H pylori strain, cagA, s1 and m1 vacA, and babA2 work synergistically in worsening inflammation. Infections caused by strains coexpressing cagA, s1m1 vacA, and babA2 are those at higher risk for intestinal metaplasia.

Gastric lymphoma: the revolution of the past decade

BACKGROUND

Gastric MALT type lymphomas are distinct lymphomas that may develop after chronic antigenic stimulation caused by infection with Helicobacter pylori. An early antigen-dependent phase precedes the development of an antigen-independent phase.

METHODS

Narrative review.

RESULTS

The causative relationship between a chronic H. pylori infection and gastric MALT lymphomas has been based on epidemiological, histological, experimental and therapeutic studies. H. pylori eradication leads to a histological remission in +/- 70% of patients in early stage low-grade MALT lymphoma. There is no basis for therapeutic consequences in the case of persistent monoclonality. Full thickness invasion of the gastric wall and lymph node involvement and/or high-grade lymphoma denote the transition to an antigen-independent phase and calls for conventional treatment modalities. Molecular findings show a specific translocation in low-grade MALT lymphomas: t(11,18) and nuclear expression of bcl-10 that are highly indicative of the transition of the antigen-dependent into the antigen-independent phase. Other chromosomal and molecular findings are probably also involved.

CONCLUSION

The multistep pathogenesis of chronic H. pylori gastritis into low-grade gastric MALT lymphoma and tumour progression to a higher stage and grade are characterized by multiple molecular biological events. Antigen-dependency during the early phase of this malignancy is proven by the results of H. pylori eradication.

Monoclonality in Helicobacter pylori-positive gastric biopsies: an early detection of mucosa-associated lymphoid tissue lymphoma

Mucosa-associated lymphoid tissue (MALT) is not present in healthy gastric mucosa, but it can develop in sites of long-persisting inflammation and is connected with the development of MALT lymphoma. A monoclonal lymphocyte population is one of the characteristics of such lymphomas. In this study we analyzed gastric biopsies (formalin fixed and paraffin embedded or frozen) in 93 patients with dyspepsia accompanied by Helicobacter pylori infection. We applied PCR and single-cell immunocytochemistry to detect the clonality of the gastric B-cell population. Immunocytochemistry performed on 33 frozen biopsies showed two samples with monoclonal pattern. PCR analysis of immunoglobulin heavy-chain (IgH) gene rearrangements revealed two monoclonal populations out of 161 biopsies from 60 patients. We conclude that PCR analysis was the most sensitive method, which gave us insight into the nature of the earliest stage of MALT lymphoma in gastric biopsies.

Expression of chemokine receptor CXCR3 and its ligand, mig, in gastric and thyroid marginal zone lymphomas. Possible migration and autocrine mechanism

Chemokine receptors mediate the migration of lymphocytes through the binding of ligands, and the expression is differentially regulated in lymphocyte subsets. CXCR3 is usually expressed in Th1 T cells, however, recently is reported to be expressed in B cell chronic lymphocytic leukemia, mucosa-associated lymphoid tissue type lymphoma (MALT) (extranodal marginal zone lymphoma), and other B cell non-Hodgkin lymphomas. Our study was designed to investigate the expression of CXCR3 and its ligand Mig, and their relationships in MALT using immunohistochemistry. In addition, CCR4, which is characteristic Th2 helper phenotype, and its ligand thymus and activation-regulated chemokine (TARC), were compared with CXCR3, as Th1 phenotype. We studied 14 cases of gastric B cell lymphoma [low-grade MALT, 5 cases; high-grade MALT, 5 cases; and diffuse large (DL), 4 cases] and 16 cases of thyroid B cell lymphoma [low-grade MALT, 4 cases; high-grade MALT, 5 cases; and DL, 7 cases]. CXCR3-expressing lymphoid cells were detected in all cases. In double immunostaining (CXCR3-CD20), gastric and thyroid low/high MALT showed CXCR3-positive neoplastic B cells, but DL, except two cases, did not. In DL, CXCR3-positive lymphoid cells were mainly reactive T-cells (CD3-positive cells). Mig was expressed mainly in stromal cells (histiocytes, macrophages, fibroblasts, and endothelial cells). In gastric lymphoma, low-grade MALT contained abundant Mig-strongly expressing cells, while staining in high-grade MALT and DL was mild. In thyroid lymphoma, staining was strong in low- and high-grade MALT, but moderate in DL. In double-staining, CXCR3-Mig-coexpressing lymphoma cells were abundant in high MALT of the stomach and thyroid, but rare in other subtypes. TARC-positive cells and CCR4-positive cells were rarely encountered in all cases. Our results indicate a tendency for low-grade MALT to contain CXCR3(+)Mig- lymphoma cells, high-grade to contain CXCR3(+)Mig+ and DL to contain CRCR3(-)Mig- lymphoma cells. We speculate that CXCR3 is associated with migration of lymphoma cells in low-grade MALT, and autocrine function in high-grade MALT, and not associated with any function in DL.

Helicobacter pylori infection in children and adults: a single pathogen but a different pathology

BACKGROUND

The aims of this retrospective study were to ascertain in large series of children and adults: the relationship of the infecting strain to gastric mucosal lesions; and the relationship of the infecting strain to its duodenal localization.

MATERIALS AND METHODS

We studied 307 and 604 consecutive children and adults. In gastric mucosal samples H. pylori was cultured, genotyped and histologically assessed, while inflammation, activity and intestinal metaplasia were graded. In a subset of 171 patients H. pylori ureaseA (ureA) and cagA genes were amplified (PCR) using mucosal biopsies from the duodenum.

RESULTS

H. pylori infection was diagnosed in 40 children and 308 adults. cagA was identified in 50% and 65.5% of infected children and adults. Antral activity was associated with the density of infecting bacteria (p <.001) and with cagA (p <.01). Intestinal metaplasia was correlated with cagA (p <.001). The ureA gene was found in 56 duodenal samples from 82 H. pylori positive patients. Duodenal H. pylori ureA was significantly more frequent in patients with duodenal diseases than in those without (p <.01), cagA positive strains being mainly involved in the infection of this anatomical area (p <.01).

CONCLUSIONS

A severe H. pylori-associated gastritis is more prevalent when the density of infecting bacteria is high and when cagA positive strains cause the infection. The most virulent cagA positive H. pylori colonizes not only the gastric, but also the duodenal mucosa, which can be directly damaged by the bacteria itself or by its products.

Gastric mucosa-associated lymphoid tissue lymphoma with adult T cell leukemia/lymphoma cell infiltration. case report

This is the first case report of gastric mucosal-associated lymphoid tissue lymphoma with adult T cell leukemia/lymphoma (ATLL) cell infiltration. A 43-yr-old Japanese woman who was seropositive for antihuman T cell leukemia virus-I antibody complained of epigastric pain in April, 1996. Endoscopy showed gastric ulcers in the antrum. Biopsy specimens showed Helicobacter pylori infection. Her symptoms were relieved by treatment with ranitidine. In March, 1998, she complained of epigastric pain and abdominal fullness. Smears of peripheral blood revealed atypical lymphocytes with nuclear irregularity, consistent with ATLL cells. She was diagnosed to have ATLL. Endoscopy revealed multiple gastric ulcers in the antrum and the angle. Biopsy specimens demonstrated small centrocyte-like cells forming lymphoepithelial lesions, with infiltrations of large atypical lymphoid cells of ATLL. On immunohistochemical staining, the small centrocyte-like cells were positive for B cell markers (L26, CD20), whereas the large atypical lymphoid cells were positive for T cell marker (UCHL-1, CD45RO). Her findings were attributed to gastric mucosal-associated lymphoid tissue lymphoma with gastric involvement with ATLL.

Detection and typing of Helicobacter pylori cagA/vacA genes by radioactive, one-step polymerase chain reaction in stool samples from children

The detection and molecular typing of Helicobacter pylori virulence genes in human stool specimens by polymerase chain reaction (PCR) require an adequate amount of bacterial DNA and an appropriately adjusted PCR protocol. DNA was isolated from stool samples of 39 H. pylori-infected and nine uninfected Colombian children using the QIAamp Kit following the manufacturer's instructions but with modifications. DNA templates were amplified for the vacA s and m regions and for the cagA gene by PCR using radioactively labeled (32P) primers. The modifications in the standard Qiagen protocol of stool DNA extraction increased the final concentration of eluted total stool DNA 4.7 times (117 +/- 17 versus 22 +/- 3 ng/microl; P < 0.0001). Nevertheless, its amplification by regular PCR programs (30-40 cycles) did not generate visible signals because of the very low ratio of H. pylori DNA to other DNA. PCR for 80 cycles successfully amplified vacA in 36/39 samples (sensitivity, 92.3%) and cagA fragments in 21/39 (53.8%) fecal DNA samples. Both s and m vacA regions were amplified in 33/36 (91.7%) DNA samples. The s1m1 genotype was the most commonly isolated variant, accounting for 17/36 or 47.2% of positive samples. The s2m2 genotype was ascertained to be frequent also (14/36 or 38.9%). Almost all (94.1%) s1m1 genotypes were cagA positive. The majority of s2m2 genotypes (78.6%) were not associated with the cagA gene. Neither cagA nor vacA fragments were amplified from DNA isolates of H. pylori-uninfected children nor from DNA isolated from six gastrointestinal bacterial strains (specificity, 100%). The data suggest that the proposed modified technique of DNA extraction and PCR assay of stool samples may be an effective and reliable noninvasive tool for the detection and typing of H. pylori cagA/vacA virulence genes in infected individuals.