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

Regression of primary high-grade gastric B-cell lymphoma following Helicobacter pylori eradication

The causative association between Helicobacter pylori and gastric mucosal inflammation is well established. The inflammatory process leads to the acquisition of mucosa-associated lymphoid tissue (MALT) by the stomach. Evidence links H. pylori gastritis with the development of low-grade primary gastric lymphoma with a phenotype specific for lymphoma of MALT type. It is now accepted that primary low-grade MALT lymphomas regress with H. pylori eradication therapy. However, the response of primary, diffuse, large-cell gastric lymphoma to H. pylori eradication therapy is still not established. We report a case of a primary high-grade gastric lymphoma regressing after H. pylori eradication therapy.

Gastric surgery

Significant advances in the role of gastric surgery in the management of disease in the past year have focused on three broad areas: morbid obesity, gastric cancer, and peptic ulcer disease. Although vertical banded gastroplasty and Roux-en-Y gastric bypass are the two procedures most commonly used in the United States to induce weight loss in the morbidly obese patient, long-term follow-up continues to support the durability of the gastric bypass in maintaining a sustainable outcome with a minimum of complications. It is not surprising, therefore, that increasing interest has accrued in simplifying this operation and decreasing potential complications even further by employing laparoscopic technology. In the area of gastric cancer, several reports have provided important new information regarding its pathogenesis, factors influencing long-term survival, and strategies for management when diagnosed early. Finally, in patients developing the complications of peptic ulcer disease (eg, obstruction and perforation), conservative management has been emphasized over more radical traditional approaches. This review highlights these advances.

Helicobacter pylori: ulcers and more: the beginning of an era

Helicobacter pylori (H. pylori) may be found in up to 50% of the world's population, making it the most common infectious disease worldwide. H. pylori is a gram-negative, microaerophilic rod with flagella and normally resides in the stomach. It can be diagnosed endoscopically, via breath tests, or through a simple blood test. H. pylori can usually be eradicated with a combination of proton pump inhibitors and antibiotics. Although most people infected with this organism never develop a complication, H. pylori infection in others may produce significant mucosal inflammation leading to ulcers in the stomach and duodenum. H. pylori has also been recognized as a risk factor for the development of both gastric carcinoma and mucosal-associated lymphoid tumor. Although not widely known, H. pylori can also affect organ systems outside of the gastrointestinal tract. It is now apparent that H. pylori can infect the skin, liver and heart and that these infections may produce a number of different disease states. In addition, H. pylori infection can adversely affect the nutritional status of both children and adults. This article discusses the epidemiology and bacteriology of H. pylori, reviews the different methods of diagnosing and treating this common infection, and then focuses on the effects that H. pylori has on different organ systems within the body, including the nutritional status of those affected.

Molecular diagnostics in low-grade gastric marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue type after Helicobacter pylori eradication therapy

The primary gastric lymphomas are extranodal non-Hodgkin's lymphomas that likely originate from the mucosa-associated lymphoid tissue (MALT). Data suggest that chronic infection with Helicobacter pylori (H pylori) is significantly associated with the pathogenesis of low-grade gastric MALT lymphomas. This is in keeping with the observation that many patients with early low-grade MALT lymphomas have complete remissions after H pylori eradication therapy. However, the stability of these remissions remains unclear and relapses have been reported. It can be difficult to distinguish between early malignant and benign disorders of the gastric mucosa. A polymerase chain reaction (PCR) assay can detect rearrangements of the variable region of immunoglobulin heavy chains. This assay can be used to distinguish the clonality of B lymphocytes and has been investigated as a test for differential diagnosis of MALT lymphomas. Monoclonality is observed in the majority of MALT-lymphoma samples at diagnosis but has been found in gastritis samples as well. Whether the presence of monoclonal B cells is associated with the risk of lymphoma progression remains unclear. As many as 50% of patients who have complete histologic remissions of MALT lymphoma after H pylori eradication therapy have persisting monoclonal bands in follow-up PCR monitoring. Although it is unclear as to whether monoclonality indicates the presence of minimal residual disease, patients who have persistent monoclonal bands during follow-up should be considered at risk for relapse. The PCR assay for rearrangements of the variable region of the immunoglobulin heavy-chain gene appears to be of low value in the diagnosis of B-cell malignancies but could provide a useful tool in the follow-up of patients who achieve remissions after H pylori eradication.

Endosonographic images of low-grade lymphoma of mucosa-associated lymphoid tissue after radiotherapy

Recently, radiation therapy has been reported to be effective in patients with low-grade lymphoma of mucosa-associated lymphoid tissue (MALT) of the stomach. We describe changes in endoscopic ultrasonographic (EUS) findings after radiation therapy in a patient with low-grade gastric MALT lymphoma. Endoscopic ultrasonography initially showed enlargement of regional lymph nodes and diffuse thickening of the second and third mural layers in the gastric body. Two months after the end of radiation therapy, EUS showed hypoechoic changes in the third layer that corresponded to the ulcer scar but no wall thickening or lymph node enlargement. The hypoechoic changes were thought to reflect inflammatory change. We conclude that EUS is useful for assessing the response to radiation therapy in patients with low-grade gastric MALT lymphoma.

Guidelines in the management of Helicobacter pylori infection in Japan

BACKGROUND

In preparation of the approval of Helicobacter pylori therapy by the Japanese national health system, the board of directors of the Japanese Society for Helicobacter Research decided to prepare guidelines on the diagnosis and treatment of H. pylori infection for physicians in routine medical practice.

METHODS

A guidelines preparation committee was formed and six meetings were held. Then, in December 1999, a consensus meeting was held in Kobe to obtain the opinions of general practitioners as well as experts from Europe, North America, and Asia.

RESULTS

Helicobacter pylori eradication therapy is recommended in gastric or duodenal ulcer patients. Helicobacter pylori eradication therapy is recommended or gastric mucosa associated lymphoid tissue (MALT) lymphoma but it should be done at specialist institutions. The significance of H. pylori eradication therapy is still under evaluation in patients with hyperplastic polyps, chronic atrophic gastritis, non-ulcer dyspepsia and in patients after endoscopic mucosal resection of gastric cancer and after gastrectomy for gastric cancer. When diagnosing H. pylori infection, at least one of the tests requiring endoscopic biopsy (e.g. rapid urease test, histology, or culture) and tests not requiring biopsy (e.g. measurement of H. pylori antibody or urea breath test) should be used. Multiple tests are recommended to increase the accuracy. The drugs of first choice currently covered by the national health insurance system in Japan are: lansoprazole (30 mg) 1 capsule twice daily, amoxicillin (250 mg) 3 capsules twice daily, and clarithromycin (200 mg) 1-2 tablets twice daily. These three drugs should be administered after breakfast and dinner for 1 week.

CONCLUSION

These guidelines are intended for utilization in routine medical practice after the Japanese national health system begins to cover the management of H. pylori infection.

Changes in pattern of immunoglobulin heavy chain gene rearrangement and MIB-1 staining before and after eradication of Helicobacter pylori in gastric mucosa-associated lymphoid tissue (MALT) lymphoma

Gastric low-grade mucosa-associated lymphoid tissue (MALT) lymphomas are strongly associated with infection by Helicobacter pylori (H. pylori). Antibiotic treatment for H. pylori induces a sustained remission in a significant number of patients. We report here the outcome in 13 patients with gastric low-grade MALT lymphomas or suspected gastric lesions, treated for eradication of H. pylori. Patients were followed closely with sequential histological studies, polymerase chain reaction (PCR) amplification of the immunoglobulin heavy chain (IgH) gene and immunohistochemistry for MIB-1. Antibiotic therapy resulted in eradication of H. pylori in all but one case, as assessed histologically. In 12 cases with successful eradication, complete regression was observed histologically in 9 cases (75%) and no regression in 3 (25%). In 7 of 9 (78%) patients who had a complete remission, clonal bands of IgH gene detected on PCR before therapy disappeared after therapy. All 9 patients with complete regression showed a reduced number of MIB-1 positive cells, while 4 cases with no change or disease progression showed no change or increased number of MIB-1 positive cells. There was a strong relationship between density of MIB-1-positive cells and histological score. These results indicate that combination analysis of PCR of IgH and MIB-1 seems to represent a very good current approach for the diagnosis of gastric low-grade MALT lymphoma and to assess the effects of chemotherapy, especially in problematic cases.

Stage I and II MALT lymphoma: results of treatment with radiotherapy

PURPOSE

Mucosa-associated lymphoid tissue (MALT) lymphoma is a distinct disease with specific clinical and pathologic features that may affect diverse organs. We analyzed our recent experience with Stage I/II MALT lymphoma presenting in the stomach and other organs to assess the outcome following involved field radiation therapy (RT).

PATIENTS AND METHODS

Seventy patients with Stage IE (62) and IIE (8) disease were treated between 1989 and 1998. Patients with transformed MALT were excluded. The median age was 62 years (range, 24--83 years), M:F ratio 1:2.2. Presenting sites included stomach, 15; orbital adnexa, 19; salivary glands, 15; thyroid, 8; lung, 5; upper airways, 3 (nasopharynx, 2; larynx, 1); urinary bladder, 3; breast, 1; and rectum, 1. Staging included site-specific imaging, CT abdomen in 66 patients (94%) and bone marrow biopsy in 54 (77%). Sixty-two patients received radiation therapy: 52 received RT alone, 7 received chemotherapy and RT, and 3 received antibiotics followed by RT. Median RT dose was 30 Gy (range, 17.5--35 Gy). Most frequently used RT prescriptions were 25 Gy (26 patients-18 orbit, 6 stomach, and 2 salivary glands), 30 Gy (23 patients), and 35 Gy (8 patients). Five patients had complete surgical excision of lymphoma and no other treatment (stomach 1, salivary 2, lung 2), whereas 2 patients with gastric lymphoma received antibiotics only. One patient refused treatment and was excluded from the analysis of treatment outcome, leaving 69 patients with a median follow-up of 4.2 years (range, 0.3-11.4 years).

RESULTS

A complete response was achieved in 66/69 patients, and 3 patients had partial response (2 lung, 1 orbit). The 5-year disease-free survival (DFS) was 76%, and the overall survival was 96%. No relapses were observed in patients with stomach and thyroid lymphoma. The 5-year DFS for these patients was 93%, in contrast to 69% for patients presenting in other sites (p = 0.006). Among the 5 patients treated with surgery only, 2 relapsed locally (lung, and minor salivary gland). Among 62 patients who received RT, 8 relapsed (2 salivary, 3 orbit, 1 nasopharynx, 1 larynx, 1 breast). Three patients relapsed in the nonirradiated contralateral paired organ, 4 in distant sites, and 1 in both local and distant sites. The overall local control rate with radiation was 97% (60/62 patients).

CONCLUSION

Localized MALT lymphomas have excellent prognosis following moderate-dose RT. Gastric and thyroid MALT lymphomas have better early outcome, as compared to the other sites where distant failure is more common. Relapses were observed in nonirradiated paired organs or distant sites. Further follow-up is required to assess the impact of failure on survival.

The Loiano-Monghidoro population-based study of Helicobacter pylori infection: prevalence by 13C-urea breath test and associated factors

OBJECTIVES

As part of a cross-sectional study on cholelithiasis, 1533 out of 1840 residents in Loiano/Monghidoro, a rural area in Northern Italy (792 men, 741 women, age range 28-80 years), agreed to be further evaluated in relation to their Helicobacter pylori status.

METHODS

Each participant performed a 13C-urea breath test (13C-UBT) and provided information on sociodemographic, lifestyle and clinical characteristics.

RESULTS

The 13C-UBT was positive in 1041 subjects (67.9%; men: 69%; women: 67%) and was positively associated with increasing age (P < 0.001), alcohol consumption (P < 0.01), a higher number of siblings (P < 0.001) and a personal history of peptic ulcer (P < 0.01), but inversely with a nonmanual occupation (P < 0.001). Overall, H. pylori infection was unrelated to smoking, house pets, and a family history of gastroduodenal diseases. The prevalence of H. pylori infection was 72% in subjects reporting one or more dyspeptic symptoms and 65% among asymptomatic participants (P < 0.001); a multivariate analysis showed that only epigastric pain was significantly, although weakly, associated with 13C-UBT positivity.

CONCLUSIONS

This large population-based study showed a prevalence of H. pylori infection higher than that reported by serologic surveys in urban areas. Current H. pylori infection was strongly associated with indicators of lower socioeconomic status, alcohol consumption and increasing age. A role of H. pylori infection in determining epigastric pain was suggested.

Clinicopathological features of gastric mucosa-associated lymphoid tissue lymphoma: a comparison with diffuse large B-cell lymphoma without a mucosa-associated lymphoid tissue lymphoma component

BACKGROUND AND AIMS

The aim of this study was to clinicopathologically distinguish the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma without a MALT lymphoma component (DLL).

METHODS

We investigated clinicopathological features of these gastric lymphomas including age, sex ratio, tumor location and depth, macroscopic appearance, and infection with Helicobacter pylori of these gastric lymphomas and hepatitis viruses in 24 patients with gastric low-grade MALT lymphoma, 10 patients with high-grade MALT lymphoma, and 19 patients with DLL. The frequency of H. pylori infection in lymphoma patients was compared with that in age- and sex-matched control subjects.

RESULTS

There was a predominance of females with MALT lymphoma (male to female ratio, 8/16 for low-grade MALT lymphomas and 1/9 for high-grade MALT lymphomas), and there was a predominance of males with DLL (male to female ratio, 13/6); the ratios differed significantly (P < 0.05). Ninety-two percent of low-grade MALT lymphomas and 80% of high-grade MALT lymphomas were confined to the mucosal and submucosal layers, but lymphoma cells invaded the muscular layer or more deeply in 74% of DLL. Helicobacter pylori infection occurred significantly more often in patients with low-grade MALT lymphoma than in age- and sex-matched controls (96 vs 67%, P < 0.01). Conversely, the frequency of H. pylori infection in DLL patients did not differ from that in controls.

CONCLUSIONS

These data suggest that H. pylori infection may be associated with the development of gastric MALT lymphoma, but not DLL, and that MALT lymphoma and DLL may have a different pathogenesis.

Lymphoid hyperplasia of the stomach: radiographic findings in five adult patients

OBJECTIVE

The purpose of our study was to report the radiographic findings of biopsy-proven lymphoid hyperplasia of the stomach in five adult patients.

CONCLUSION

Lymphoid hyperplasia of the stomach is characterized by distinctive findings on double-contrast upper gastrointestinal tract barium examinations; all five patients had innumerable tiny (1--3 mm in diameter) round frequently umbilicated nodules that carpeted the mucosa of the gastric antrum or antrum and body. Three of these five patients had associated Helicobacter pylori gastritis. The diagnosis of gastric lymphoid hyperplasia, therefore, can be suggested on the basis of the radiographic findings.

Are lymphocytic monoclonality and immunoglobulin heavy chain (IgH) rearrangement premalignant conditions in chronic gastritis?

Normal gastric mucosa is devoid of lymphoid cells. Any increase of lymphocytes suggests chronic inflammation. Infection with Helicobacter pylori (Hp) is the major cause for nonautoimmune chronic gastritis and induces a mixed cellular response resulting in an acquired lymphoid tissue, or MALT (mucosa-associated lymphoid tissue). Hp has also been implicated in the genesis of gastric MALT-lymphoma. Polymerase chain reaction-based assays to detect the expansion of monoclonal B-cells have also been used to corroborate the diagnosis. In a considerable number of cases monoclonal B-cells remain detectable in follow-up biopsies, with the lymphoma being in complete histological remission. The clinical relevance of this finding is not clear yet. However, there also exist different reports that monoclonal B-cells can be found in gastric biopsies of patients with neither a histological sign nor a present or past history of lymphoma. In the light of these findings we address the question whether B-cell monoclonality can be seen as a premalignant condition in chronic gastritis and conclude that as of now the relevance of the finding of B-cell monoclonality remains unclear. As of now the only and gold standard for the diagnosis of gastric MALT-lymphoma is histopathology.

Molecular aspects of B-cell lymphomas of the gastrointestinal tract

The B-cell lymphomas of the gastrointestinal (GI) tract have represented a field of extensive research ever since a close association was shown with such chronic inflammatory processes as Helicobacter pylori infection. Evidence suggested that the mucosa-associated lymphoid tissue induced by inflammation and autoimmune processes is the environment that gives rise to the small-cell lymphomas of the GI tract (eg, extranodal marginal zone B-cell lymphoma according to Revised European-American Classification of Lymphoid Neoplasms and the World Health Organization Classification of Neoplastic Diseases of the Hematopoietic and Lymphoid Tissue). The small B-cell lymphoma may then progress to highly malignant variants. The B-cell lymphomas of the GI tract may present a stepwise model for lymphomagenesis and progression. This review covers molecular biology and molecular cytogenetic aspects that lead to new insights into the biology of GI lymphomas and potential prognostic factors.

Review article: should we kill or should we save Helicobacter pylori?

Results from epidemiological studies and therapeutic clinical trials have shown that Helicobacter pylori infection causes acute and chronic active gastritis and is the initiating factor for the majority of peptic ulcer disease. Eradication of the infection with antibiotics resolves gastritis and restores normal gastric physiology, accelerates healing of peptic ulcer disease, and virtually eliminates recurrence of duodenal ulcer disease. The infection also plays an important role in the initiation and/or progression of gastric atrophy and intestinal metaplasia, which may eventually lead to the development of distal gastric cancer. Furthermore, almost all patients with gastric MALT lymphoma are infected with H. pylori and cure of the infection leads to histological regression of the tumor and maintains the regression in over 80% of patients during long-term follow-up. Preliminary uncontrolled data from Japan show that eradication of the infection significantly reduced metachronous intestinal-type gastric cancer following initial endoscopic resection of early gastric cancer and might also prevent the progression of gastric adenoma to gastric dysplasia or gastric cancer. Although this overwhelming evidence has demonstrated that H. pylori infection is bad for humans, some have questioned the wisdom of eradicating the infection in all those infected. Their arguments are largely based on hypothesis and circumstantial evidence: 1) Less than 20% of all H. pylori infected persons will develop significant clinical consequences in their lifetime. 2) H. pylori strains are highly diverse at a genetic level and are of different virulence. 3) The antiquity of H. pylori infection in humans and their co-evolution suggests that H. pylori may be a commensal to humans. Eradication of H. pylori may remove some beneficial bacterial strains and may provoke esophageal disease or gastric cancer at the cardia. However, careful review of the literature confirms that H. pylori infection is a serious pathogen albeit in a minority of those infected. It remains for carefully designed prospective studies, rather than hypothesis to make changes in the current consensus position.

Development of early gastric cancer 4 and 5 years after complete remission of Helicobacter pylori associated gastric low grade marginal zone B cell lymphoma of MALT type

AIM: To report 3 of 120 patients on the German MALT lymphoma trial with H. pylori associated gastric MALT lymphoma who developed early gastric cancer 4 and 5 years, after complete lymphoma remission following cure of H. pylori infection.

PATIENTS AND RESULTS: Three patients (two men, 74 and 70 years; one women, 77 years) with H. pylori-associated low-grade MALT lymphoma achieved complete lymphoma remission after being cured. Surveillance endoscopies were performed twice a year in accordance to the protocol. Four years after complete lymphoma remission in two patients, and after 5 years in the other, early gastric adenocarcinoma of the mucosa-type, type II a and type II c, respectively, was detetcted, which were completely removed by endoscopic mucosa resection. In one patient, the gastric cancer was diagnosed at the same location as the previous MALT lymphoma, in the other patients it was detected at different sites of the stomach distant from location of the previous MALT lymphoma. The patients were H. pylori negative during the whole follow-up time.

CONCLUSION: These findings strengthen the importance of regular Long term follow-up endoscopies in patients with complete remission of gastric MALT lymphoma after cure of H. pylori infection. Furthermore, gastric adenocarcinoma may develop despite eradication of H. pylori.

Helicobacter pylori and gastric cancer: current status of the Austrain-Czech-German gastric cancer prevention trial (PRISMA-Study)

AIM: To test the hypothesis that Helicobacter pylori eradication alone can reduce the incidence of gastric cancer in a subgroup of individuals with an increased risk for this fatal disease.

METHODS: It is a prospective, randomized, double blind, placebo controlled multinational multicenter trial. Men between 55 and 65 years of age with a gastric cancer phenotype of Helicobacter pylori gastritis are randomized to receive a 7 day course of omeprazole 2 × 20 mg, clarithromycin 2 × 500 mg, and amoxicillin 2 × 1 g for 7 days, or omeprazole 2 × 20 mg plus placebo. Follow-up endoscopy is scheduled 3 months after therapy, and thereafter in one-year intervals. Predefined study endpoints are gastric cancer, precancerous lesions (dysplasia, adenoma), other cancers, and death.

RESULTS: Since March 1998, 1524 target patients have been screened, 279 patients (18.3%) had a corpus dominant type of H. pylori gastritis, and 167 of those were randomized (58.8%). In the active treatment group (n = 86), H. pylori infection infection was cured in 88.9% of patients. Currently, the cumulative follow-up time is 3046 months (253. 38 patient years, median follow up 16 months). So far, none of the patients developed gastric cancer or any precancerous lesion. Three (1.8%) patients reached study endpoints other than gastric cancer.

CONCLUSION: Among men between 55 and 65 years of age, the gastric cancer phenotype of H. pylori gastritis appears to be more common than expected. Further follow up and continuing recruitment are necessary to fulfil the main aim of the study.

Helicobacter pylori vacA, iceA, and cagA status and pattern of gastritis in patients with malignant and benign gastroduodenal disease

OBJECTIVE

Both bacterial virulence factors and the pattern of Helicobacter pylori (H. pylori) gastritis may contribute to the development of clinically relevant gastroduodenal disease. The aim of our study was to investigate the frequency of H. pylori vacA alleles, iceA, and cagA, and the pattern of gastritis in patients with gastric cancer (GC), gastric lymphoma (MALT), duodenal ulcer (DU), and functional dyspepsia (FD).

METHODS

H. pylori was cultured from 141 patients (34 GC, 26 MALT, 49 DU, 32 FD). Allelic variants of vacA and iceA, and cagA were identified by polymerase chain reaction. Antrum and corpus biopsies were obtained for assessment of gastritis according to the updated Sydney System.

RESULTS

The vacA sl,ml genotype was more frequently detected in H. pylori from GC patients (70.6%) than from MALT, DU, and FD patients (p < 0.05). The frequency of iceA1 and cagA did not differ among the groups. The proportion of patients with severe gastritis in the corpus was significantly higher in patients with GC and MALT compared with patients with DU (p < 0.001).

CONCLUSIONS

In a German patient population, only the vacA s1,m1 genotype of H. pylori is associated with GC, and therefore may be useful to identify infected patients being at an increased risk for GC.

Complete remission of primary high-grade B-cell gastric lymphoma after cure of Helicobacter pylori infection

PURPOSE

Treatment of low-grade gastric mucosa-associated lymphoid tissue lymphoma by eradication of Helicobacter pylori is reported to result in complete lymphoma remission in approximately 75% of cases. The effect that cure of the infection has on the course of a primary high-grade gastric lymphoma is largely uncertain. The aim of this study was to report the effect of cure of H pylori infection exerted in patients with high-grade B-cell gastric lymphoma.

PATIENTS AND METHODS

Eight patients (4 males and 4 females; age range, 26 to 85 years) with H pylori infection and high-grade lymphoma received eradication therapy before planned treatment. The effect of H pylori eradication on the course of high-grade lymphoma was assessed by analysis of surgical specimens (n = 2) or endoscopic biopsies (n = 6).

RESULTS

H pylori eradication was successful in all patients and led to complete remission of the lymphoma in seven patients. One patient has experienced partial remission. Two patients were referred to surgery, one of whom (stage II(1E)) had lymph node involvement, and the histologic work-up of the resected stomach revealed residual infiltrates of a low-grade lymphoma, which prompted consolidation chemotherapy. In one patient (initially stage I(1E)), abdominal lymphoma developed 6 months after eradication therapy, which regressed completely after chemotherapy. In four patients, no further treatment was given. Six patients continue in complete remission (range, 6 to 66 months).

CONCLUSION

Primary high-grade B-cell gastric lymphoma in stages I(E) through II(E1) associated with H pylori may regress completely after successful cure of the infection. Prospective trials are needed to investigate this treatment in larger numbers of patients.

Gastrointestinal lymphoma: prevention and treatment of early lesions

Gastrointestinal lymphomas comprise a group of distinct clinicopathological entities. Differences in lifestyle and environmental factors between countries could account for the variety in the distribution of the main subtypes: low-grade B-cell lymphomas of the mucosa-associated lymphoid tissue type, alpha-chain disease and enteropathy (coeliac disease)-associated T-cell lymphoma (EATL). The possibility of preventing these lymphomas implies a knowledge of their natural history together with an identification of potential predisposing factors. The development of the lymphoid hyperplasia and subsequently low-grade lymphoma with the possibility of high-grade transformation is a multifactorial process involving both antigenic and host-related factors. The pathogenic role of Helicobacter pylori and gluten has been demonstrated in gastric lymphoma and enteropathy-associated T-cell lymphoma respectively, while environmental factors, especially non-specific bacterial ones, may play a major role in the pathogenesis of alpha-chain disease. The most difficult task in preventing these lymphomas is the recognition of early lesions likely to regress after the removal of the exogenous stimulus.

Primary extranodal mucosa associated lymphoid tissue (MALT) lymphoma of the prostate

Low-grade B-cell mucosa associated lymphoid tissue (MALT) lymphoma can rarely present primarily in extranodal sites other than stomach, which is the most common site for it. Until now only four cases of primary prostatic MALTomas have been described in the literature and we report the fifth. We describe a case of primary prostatic MALToma in a 67-year-old man and the diagnosis was made on the trans-urethral resection specimen of the prostate. As the disease was limited to prostate (stage IEA), the patient was treated with external beam radiation therapy to a total dose of 4400cGy in 22 fractions. The patient achieved completed remission and has remained free of disease in the following 36 months.

Diffuse large B-cell non-Hodgkin's lymphoma presenting as a vaginal mass in a patient with a history of intestinal mucosa-associated lymphoid tissue (MALT) lymphoma

Vaginal involvement in non-Hodgkin's lymphoma is uncommon and is often secondary to disseminated disease. Primary disease at this site is quite rare. We present here an unusual case of a patient who developed a diffuse large B-cell lymphoma presenting as a vaginal mass after having been treated for primary intestinal mucosa-associated lymphoid tissue (MALT) lymphoma 4 years earlier. Combined chemotherapy and radiation therapy for the intestinal MALT lymphoma produced complete remission that lasted for 2 years. Chemotherapy given for the diffuse large B-cell lymphoma with secondary vaginal involvement produced a second complete remission. The second remission was consolidated with high-dose chemotherapy and autologous bone marrow transplantation. Although the patient died from complications related to the transplant procedure, the disease was in complete remission at the time of her death. Given the rarity of primary intestinal MALT lymphoma and primary vaginal lymphoma, no standard treatment has been established. Treatment options have included chemotherapy, radiation therapy, or surgery, given alone or in combination.

Long-term persistence of monoclonal B cells after cure of Helicobacter pylori infection and complete histologic remission in gastric mucosa-associated lymphoid tissue B-cell lymphoma

PURPOSE

Cure of Helicobacter pylori infection is associated with remission induction in the majority of patients with low-grade gastric mucosa associated lymphoid tissue (MALT) lymphoma in localized stages; however, limited data exist as to whether these patients may be cured of their lymphoma. The present study was performed to investigate whether the polymerase chain reaction (PCR) for the rearranged immunoglobulin heavy chain region may be used to define "molecular" remission.

PATIENTS AND METHODS

Ninety-seven patients who suffered from low-grade gastric MALT lymphoma stage I(E) were observed with central pathology and molecular biology after cure of H pylori infection. PCR was performed with the use of consensus primers for the framework regions 1, 2, and 3 and monoclonality was corroborated by sequence analysis. In selected cases, microdissection was performed to study the origin of the monoclonal B cells.

RESULTS

Of the 97 patients, 77 obtained complete endoscopic and histologic remission (CR). Twenty of 44 patients with PCR monoclonality at diagnosis and with sufficient molecular follow-up displayed monoclonal bands for a median time of 20.5 months after CR (range, 0 to 50.4 months). These B cells were related to the original lymphoma clone by sequence analysis. Microdissection analysis identified basal lymphoid aggregates as the source of these monoclonal B cells. Local relapse occurred in and was observed by PCR in four patients. All four patients displayed monoclonal PCR before relapse, and three of these four showed ongoing PCR monoclonality throughout their course, indicating the persistence of malignant cells.

CONCLUSION

Half of all patients with gastric MALT lymphoma show long-term PCR monoclonality up to several years after cure of H pylori infection and CR. Patients with monoclonal PCR should be observed closely, whereas long-term PCR negativity may indicate cure of the disease.

Reduced intracellular survival of Helicobacter pylori vacA mutants in comparison with their wild-types indicates the role of VacA in pathogenesis

The vacuolating cytotoxin VacA of Helicobacter pylori plays an important but yet unknown role in pathogenesis. We studied the impact of the vacuolating cytotoxin on H. pylori invasion of and survival within AGS cells (human gastric cell line derived from an antral adenocarcinoma). Isogenic vacA and cagA mutants were constructed in a wild-type clinical isolate H. pylori, AF4. An H. pylori VacA-deficient mutant, AF4(vacA::kan), was cultured in significantly lower numbers from AGS cells after 24 h incubation with gentamicin added to the culture medium than were the type I wild-type strain AF4 (P<0.03) and an isogenic cagA mutant (P<0.01). Complementation of the AF4 vacA mutant with broth culture supernatant from wild-type AF4 improved the intracellular survival of the vacA mutant. We conclude that H. pylori's vacuolating cytotoxin improves the intracellular survival of H. pylori within AGS cells, suggesting the role of the vacuolating cytotoxin in H. pylori pathogenesis.

Acid-induced gene expression in Helicobacter pylori: study in genomic scale by microarray

To understand the RNA expression in response to acid stress of Helicobacter pylori in genomic scale, a microarray membrane containing 1,534 open reading frames (ORFs) from strain 26695 was used. Total RNAs of H. pylori under growth conditions of pH 7.2 and 5.5 were extracted, reverse transcribed into cDNA, and labeled with biotin. Each microarray membrane was hybridized with cDNA probe from the same strain under two different pH conditions and developed by a catalyzed reporter deposition method. Gene expression of all ORFs was measured by densitometry. Among the 1,534 ORFs, 53 ORFs were highly expressed (> or = 30% of rRNA control in densitometry ratios). There were 445 ORFs which were stably expressed (<30% of rRNA in densitometry) under both pH conditions without significant variation. A total of 80 ORFs had significantly increased expression levels at low pH, while expressions of 4 ORFs were suppressed under acidic condition. The remaining 952 ORFs were not detectable under either pH condition. These data were highly reproducible and comparable to those obtained by the RNA slot blot method. Our results suggest that microarray can be used in monitoring prokaryotic gene expression in genomic scale.

Histological and immunological parameters to predict treatment outcome of Helicobacter pylori eradication in low-grade gastric MALT lymphoma

Helicobacter pylori eradication is generally accepted as the first choice of treatment for stage IE low-grade gastric MALT lymphoma (mucosa-associated lymphoid tissue-type lymphoma). Treatment failure may be attributed to the extent of the disease and to progression into an antigen-independent phase. This study assessed the value of morphological grading and the expression of the co-stimulatory markers CD40, CD80 and CD86 and their ligands to predict clinical outcome in 23 consecutive low-grade MALT lymphoma patients treated with H. pylori eradication. Complete regression was achieved in 13/23 patients (56%), partial regression in two (9%), and no response in eight (35%). Histological grading was highly predictive of clinical response, especially in stage IE(1) patients, with complete remissions in 10/12 tumours with purely low-grade (type A) morphology and 1/8 tumours with increased numbers of blasts (type B) (p=0.0046) and was related to the expression of costimulatory markers (p=0.0061). Moreover, CD86 as a single marker proved to be of predictive value for treatment outcome (p=0.0086). These results suggest that morphological grading and immunological criteria can be defined to recognize the transition into the antigen-independent phase of gastric MALT-NHL. In addition to clinical stage, these critera may in future serve as a practical pathological guide to the choice of therapy.

Comparison of clinical, serological and histological findings between non-ulcer dyspepsia patients with and without Helicobacter pylori infection

BACKGROUND AND AIMS

The role of Helicobacter pylori (H. pylori) infection in non-ulcer dyspepsia (NUD) remains controversial. This study investigates the clinical, serological and histological differences between patients with H. pylori-positive and -negative NUD.

METHODS

One hundred and eighty consecutive patients with NUD were enrolled from January to December 1998. The severity of symptoms was evaluated by the Tucci's scoring system. The histological changes of gastric mucosa were assessed according to the Updated Sydney System, and a fasting blood sample was obtained to test the serum gastrin and pepsinogen I levels.

RESULTS

The H. pylori-positive NUD patients were notably older than H. pylori-negative NUD patients (48.2 +/- 15.9 vs 39.8 +/- 15.7 years, P= 0.001). There were no differences in other clinical factors between the two NUD groups. The serum pepsinogen I levels were considerably higher in H. pylori-positive NUD patients than in H. pylori-negative NUD patients (78.9 +/- 42.2 vs 61.5 +/- 43.3 ng/mL, P<0.01). However, no significant differences in serum gastrin levels were discovered between the two groups. The antrum histological scores for chronic inflammation, acute inflammation, gland atrophy and lymphoid follicles were higher in H. pylori-positive NUD patients than in H. pylori-negative NUD patients (2.09 vs 1.01, P<0.001; 1.22 vs 0.36, P<0.001; 0.76 vs 0.36, P<0.01; 0.33 vs 0.13, P<0.01, respectively).

CONCLUSIONS

The present study discovered marked differences in age, serum pepsinogen I levels, histological grades of acute inflammation, chronic inflammation, gland atrophy and lymphoid tissue formation between H. pylori-positive and H. pylori-negative NUD patients. Further investigation of the clinical prognosis of the two groups of patients is necessary.

MALT lymphoma presenting as a cystic salivary gland mass

BACKGROUND

Mucosa associated lymphoid tissue (MALT) lymphoma has been noted to involve the salivary glands in chronic inflammatory conditions such as Sjogren's syndrome and in HIV infection.

METHODS AND RESULTS

The authors encountered a patient with bilateral cystic changes in the parotid glands which proved to be due to MALT lymphoma. The clinical course, histopathology, and treatment options of MALT lymphoma in the salivary gland are discussed in detail.

CONCLUSION

This malignant entity should be considered in the differential diagnosis of refractory cystic lesions of the salivary glands.

The disease spectrum of Helicobacter pylori: the immunopathogenesis of gastroduodenal ulcer and gastric cancer

Helicobacter pylori is a gram-negative bacterium that resides under microaerobic conditions in a neutral microenvironment between the mucus and the superficial epithelium of the stomach. From this site, it stimulates cytokine production by epithelial cells that recruit and activate immune and inflammatory cells in the underlying lamina propria, causing chronic, active gastritis. Although epidemiological evidence shows that infection generally occurs in children, the inflammatory changes progress throughout life. H. pylori has also been recognized as a pathogen that causes gastroduodenal ulcers and gastric cancer. These more severe manifestations of the infection usually occur later in life and in a minority of infected subjects. To intervene and protect those who might be at greatest risk of the more severe disease outcomes, it is of great interest to determine whether bacterial, host, or environmental factors can be used to predict these events. To date, several epidemiological studies have attempted to define the factors affecting the transmission of H. pylori and the expression of gastroduodenal disease caused by this infection. Many other laboratories have focused on identifying bacterial factors that explain the variable expression of clinical disease associated with this infection. An alternative hypothesis is that microorganisms that cause lifelong infections can ill afford to express virulence factors that directly cause disease, because the risk of losing the host is too great. Rather, we propose that gastroduodenal disease associated with H. pylori infection is predominantly a result of inappropriately regulated gastric immune responses to the infection. In this model, the interactions between the immune/inflammatory response, gastric physiology, and host repair mechanisms would dictate the disease outcome in response to infection.

Primary Gastric Lymphoma

The pathogenesis of gastric MALT lymphoma starts with accumulation of MALT following infection of the stomach by H. pylori. Rarely this lymphoid infiltrate contains cells with a growth advantage possibly due to a genetic change (trisomy 3?). The result is a monoclonal lymphoproliferative lesion which is responsive to H. pylori driven T-cell help. Because its growth is dependent on the presence of local antigen, gastric MALT lymphoma remains localized for long periods and it is during this phase that the lymphoma can be treated by eradication of H. pylori. Further genetic changes, as yet uncharacterized may lead to escape from T-cell dependency and ultimately high grade transformation.

Helicobacter pylori infection--current treatment practice

Helicobacter pylori infection, which is present in 30 - 60% of the population in developed countries and in more than 60% in developing countries, is established to be a major cause of gastritis, peptic ulcer disease and gastric cancer. Eradication therapy has been incorporated into clinical practice over the past 15 years. Treatment regimens include a 2 week bismuth-based triple therapy (a bismuth compound plus metronidazole, tetracycline or amoxycillin), a 1 week proton-pump inhibitor (PPI)-based triple therapy and a 1 week ranitidine bismuth citrate (RBC)-based triple therapy (a PPI or RBC plus any two of the three antibiotics, metronidazole, amoxycillin and clarithromycin). These regimens achieve eradication rates of >> 80%. H. pylori resistance to metronidazole and clarithromycin decreases the clinical efficacy of most regimens, despite the high eradication rates for resistant strains achieved by the RBC-triple therapy in some recent trials. The dose of antibiotics (especially clarithromycin) and the duration of treatment may also influence the eradication rate. Doctors' beliefs impact on clinical practice and, thus, influence the clinical application of eradication therapy. Whereas peptic ulcer disease and primary gastric low-grade B-cell mucosa-associated lymphoid tissue lymphoma (MALToma) have become established as definite indications for eradication therapy, there remain controversies surrounding non-ulcer dyspepsia, gastro-oesophageal reflux disease, atrophic gastritis, intestinal metaplasia, use of non-steroidal anti-inflammatory drugs (NSAIDs) and H. pylori-related extradigestive diseases.

Prognostic significance of the histopathologic recognition of low- and high-grade components in stage I-II B-cell gastric lymphomas

The prognostic value of histopathologic features was assessed in 83 patients with stage I-II gastric B-cell lymphomas (PGL). The following histotypes were considered: low-grade mucosa-associated lymphoid tissue (MALT)-type lymphoma (LGML; n = 35), diffuse large B-cell lymphoma with areas of MALT-type lymphoma (DLCLML; n = 20) and diffuse large B-cell lymphoma without areas of MALT-type lymphoma (DLCL; n = 28). Low-grade (LG) and high-grade (HG) components, lymphoepithelial lesions (LEL), size of cells giving rise to LEL, and amount and growth pattern of large cells (LC) were analyzed. Five-year cause-specific survival (CSS) for patients with LGML, DLCLML, and DLCL were 94%, 84%, and 64%, respectively (p = 0.05). LG component or LEL were associated with a significantly longer 5-year CSS, whereas the presence of an HG component, defined as clustered LC greater than 10% of neoplastic population, was significantly related to a shorter survival. Lymphomas with LC disposed in clusters were associated with a worse survival in comparison with cases with scattered LC. The presence of scattered LC 5%-10% appeared irrelevant in LGML. When analysis was limited to DLCLML/ DLCL patients, the presence of LG component or LEL was associated with a significantly longer 5-year CSS, whereas the existence of LEL formed by LC (HG LEL) did not modify survival. Multivariate analysis, adjusted by the main prognostic factors, confirmed the independent and significant association between histopathologic categorization and survival. Age, stage, lactate dehydrogenase (LDH) ratio, thrombocytopenia, and use of chemotherapy had independent prognostic value. In conclusion, histopathologic categorization is an independent prognosticator in PGL. The formation of compact clusters by LC, rather than their amount, is a true prognostic variable. The presence of scattered LC 5%-10% appears irrelevant in LGML. LG component and LEL are favorable predictors in HG lymphomas, helping to identify two subsets of DLCL with different prognosis.

MALT Lymphomas

This review addresses the biology and the treatment of lymphomas arising from mucosa-associated lymphoid tissue (MALT). This entity, first described in 1983, represents about 8% of all non-Hodgkin's lymphomas and was recently re-classified as "extranodal marginal zone lymphomas of MALT-type." The term marginal zone lymphoma (MZL) encompasses the three closely related lymphoma subtypes of nodal, primary splenic and extranodal lymphomas of MALT type: the latter represent the vast majority of MZL. These lymphomas arise at different anatomic sites, are composed of mature B-cells lacking expression of CD5 and CD10, often present with overlapping morphologic features, but typically quite distinct clinical behaviors. Only very recently cytogenetic/molecular genetic observations have underlined the distinctiveness of these three lymphoid neoplasms, which in both the R.E.A.L. and WHO-classifications are included in the general term of MZL. MALT lymphomas arise in numerous extranodal sites, but gastric MALT lymphoma is the most common and best studied and is, therefore, the paradigm for the group as a whole. Dr. Isaacson describes the principal histological features of these lymphomas, including criteria to distinguish this entity from other small B-cell lymphomas. Several lines of evidence suggest that gastric lymphoma arises from MALT acquired as the result of aH. pyloriinfection. However, at least 1/3 of cases do not respond to eradication ofH. pylori. Very recent data suggest that both t(11;18) (q21;q21) and bcl10 nuclear expression are associated with failure to respond to this treatment. Dr. Gascoyne discusses the biologic function of proteins deregulated through the different translocations, which play a role in pathogenesis of MALT lymphomas, emphasizing particularly their influence in disrupting the apoptotic pathway. Dr. Zucca reviews findings suggesting that MALT lymphoma is an antigen driven neoplasm. He also presents specific guidelines for treatment of gastric lymphomas trying to shed some light on the amazingly inconsistent and confusing data in the literature. Taking advantage on the more than 300 non-gastric MALT lymphomas collected by the International Extranodal Lymphoma Study Group (ILESG), Dr. Cavalli compares gastric lymphomas with those arising in many other sites. Overall, the data presented in this session will underline the fact, that MALT lymphomas are characterized by some unique biological properties.

Cut-off point, timing and pitfalls of the 13C-urea breath test as measured by infrared spectrometry

BACKGROUND

The best timing and the best cut-off level of the 13C-urea breath test have not yet been well established.

AIMS

To evaluate the cut-off value and the influence of medication on the 13C-urea breath test as measured by infrared spectrometry.

METHODS

A series of 223 patients, sent for endoscopy performed 13C-urea breath test in fasting conditions with 75 mg of 13C-urea and 20 ml of citric acid. Breath samples were collected before and then 10, 20, 25 and 30 minutes after ingestion. As gold standard, histological examination of gastric biopsies was used. A questionnaire was completed concerning the intake of medication, likely to influence the test, in the 2 months preceding the test. Sensitivity, specificity, positive predictive value and negative predictive value at 10, 20, 25 and 30 minutes at different cut-off values (3, 3. 5, 4, 4. 5, 5.0 0/00 DOB] were calculated.

RESULTS

A total of 182 patients did not take medication. There was no significant difference between the different cut-off levels at different times. Compared with the group of 41 patients who did take medication, likely to influence the test, the differences were significant (Fisher exact test).

CONCLUSION

There was no significant difference between the different cut-off values. A 10-minute test with a cut-off level between 4 and 5% delta over baseline (sensitivity: 100%, specificity: 95%) is, therefore, proposed. To avoid false negative results due to unknown intake of medication, every patient submitted to the 13C-urea breath test should fill out a questionnaire.

A critical review of the effect of Helicobacter pylori eradication on gastric MALT lymphoma

Low-grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) are thought to arise within organized lymphoid tissue in the gastric mucosa that is most frequently acquired in response to Helicobacter pylori infection. This close association between the organism and the lymphoma is further reflected by the demonstration that the proliferation of the lymphoma cells can be driven by the presence of H. pylori organisms through a complex path of cellular interactions involving specific T cells. From these observations it was suggested that removal of one of the proliferative drives to the neoplastic cells in the form of eradication of the organism might induce a remission in the tumor. Several large multicenter studies are now underway to consider this question, and interim reports suggest that long-term remissions can be induced in low-grade MALT lymphomas in 70% to 80% of cases. The lymphomas that are most likely to respond to H. pylori eradication are those that are located superficially within the gastric mucosa. It has been suggested that certain genetic abnormalities, such as t(11;18) and the Bcl-10 mutation, may be associated with lack of response to this therapy. Recurrences of low-grade lymphoma are encountered in patients treated by H. pylori eradication, but these appear to be infrequent and may be self-limiting and spontaneously regress without further therapy.

Primary gastric B-cell lymphoma: results of a prospective multicenter study. The German-Austrian Gastrointestinal Lymphoma Study Group

BACKGROUND & AIMS

Appropriate management of primary gastric lymphoma is controversial. This prospective, multicenter study aimed to evaluate the accuracy of endoscopic biopsy diagnosis and clinical staging procedures and assess a treatment strategy based on Helicobacter pylori status and tumor stage and grade.

METHODS

Of 266 patients with primary gastric B-cell lymphoma, 236 with stages EI (n = 151) or EII (n = 85) were included in an intention-to-treat analysis. Patients with H. pylori-positive stage EI low-grade lymphoma underwent eradication therapy. Nonresponders and patients with stage EII low-grade lymphoma underwent gastric surgery. Depending on the residual tumor status and predefined risk factors, patients received either radiotherapy or no further treatment. Patients with high-grade lymphoma underwent surgery and chemotherapy at stages EI/EII, complemented by radiation in case of incomplete resection.

RESULTS

Endoscopic-bioptic typing and grading and clinical staging were accurate to 73% and 70%, respectively, based on the histopathology of resected specimens. The overall 2-year survival rates for low-grade lymphoma did not differ in the risk-adjusted treatment groups, ranging from 89% to 96%. In high-grade lymphoma, patients with complete resection or microscopic tumor residuals had significantly better survival rates (88% for EI and 83% for EII) than those with macroscopic tumor residues (53%; P < 0.001).

CONCLUSIONS

There is a considerable need for improvement in clinical diagnostic and staging procedures, especially with a view toward nonsurgical treatment. With the exception of eradication therapy in H. pylori-positive low-grade lymphoma of stage EI and the subgroup of locally advanced high-grade lymphoma, resection remains the treatment of choice. However, because there is an increasing trend toward stomach-conserving therapy, a randomized trial comparing cure of disease and quality of life with surgical and conservative treatment is needed.

Heterogeneity of the API2-MALT1 gene rearrangement in MALT-type lymphoma

The translocation t(11;18)(q21;q21), which is the most frequent chromosomal aberration in extranodal marginal zone B cell lymphomas of MALT-type, was characterised in a series of 34 biopsies, including 18 gastric non-Hodgkin's lymphomas (NHL) of MALT-type, six MALT-type NHL of extragastral origin and 10 extranodal large B cell lymphomas (LBL). Based on fluorescence in situ hybridisation, STS-PCR analysis and screening of genomic PAC libraries, a physical map of contiguous DNA probes on chromosome 11 was constructed containing the anti-apoptotic genes API2 and API1 adjacent to the translocation breakpoint. RACE-PCR experiments revealed MALT1 the chromosome 18-derived fusion partner of API2, which has also been reported recently by other groups. RT-PCR analysis and DNA sequencing demonstrated the expression of an API2-MALT1 fusion transcript in 18/24 gastral and extragastral MALT-type lymphomas. In none of 10 LBLs was a translocation specific RT-PCR product detected. Five variants of the fusion transcript were identified and in all instances the open reading frame of the fused portion of the MALT1 gene was maintained. The molecular analysis of these variants allowed the design of optimised assays for the diagnosis of the API2-MALT1 gene rearrangement.

Association of Helicobacter pylori infection with atrophic gastritis and intestinal metaplasia

AIMS

To evaluate the effect of Helicobacter pylori infection and aging on atrophy and intestinal metaplasia of the gastric mucosa.

METHODS

One hundred and sixty-three patients were divided into three age groups and underwent an upper gastrointestinal endoscopy where no esophagitis, peptic ulcers, or malignancies were detected. Two biopsy specimens were obtained from the anterior and posterior walls of the antrum and of the fundus. These were used to evaluate the grade of gastritis, bacterial culture and histologic evidence of H. pylori infection.

RESULTS

Helicobacter pylori infection was found to be directly associated with an increased risk of gastritis grade (odds ratio (OR) = 90 (95% CI; 30-270)). An age of 60 years and older along with H. pylori infection was also strongly associated with an increased risk of atrophy (OR = 6.6, (95% CI; 2.9-15.2)); OR = 9.8, (95% CI; 2.7-35.4)), as was intestinal metaplasia of the gastric mucosa (OR = 5.5, (95% CI; 1.7-17.6)); OR = 7.9, (95% CI; 2.8-46.1)). The prevalence of atrophic gastritis increased with advancing age in H. pylori-infected patients, but no such phenomenon was observed in H. pylori-uninfected patients. The prevalence of intestinal metaplasia significantly increased with advancing age, irrespective of the presence of H. pylori infection. In addition, H. pylori uninfected female patients had a decreased risk of intestinal metaplasia.

CONCLUSIONS

These results suggest that atrophic gastritis is not a normal aging process, but instead is likely to be the result of H. pylori infection, while intestinal metaplasia is caused by both the aging process and H. pylori infection. A decreased risk of intestinal metaplasia found in uninfected female subjects may partly explain the lower prevalence of gastric cancer in females than in males.

Endoscopic characteristics of low-grade gastric mucosa-associated lymphoid tissue lymphoma after eradication of Helicobacter pylori

BACKGROUND AND AIMS

It was recently reported that low-grade gastric lymphoma of mucosa-associated lymphoid tissue (MALT) was regressed by the eradication of Helicobacter pylori. The aim of this study was to confirm the effect of H. pylori eradication on low-grade gastric MALT lymphoma and to investigate the whitish mucosa that appeared with regression of the lesions.

METHODS

Forty-seven H. pylori-positive patients with low-grade gastric MALT lymphoma were treated by using triple therapy. Biopsy specimens were histologically graded and B cell clonality was examined by using reverse transcription-polymerase chain reaction before and after eradication treatment. The relationship between the appearance of whitish mucosa and the degree of gastric gland loss was evaluated.

RESULTS

Histologic regression was observed 2 months after eradication therapy in 42 of 47 patients. However, B cell monoclonality changed to polyclonality in only 23 patients during the follow-up period. The appearance of whitish mucosa in patients who showed histologic regression became more frequent as the degree of gastric gland loss increased (P< 0.001).

CONCLUSIONS

Most low-grade gastric MALT lymphoma histologically regressed after H. pylori eradication. The appearance of whitish mucosa after histologic regression reflected the degree of gastric gland loss. Whitish mucosa is an endoscopic characteristic and may be an endoscopic marker for regression of low-grade gastric MALT lymphoma.

Different patterns of Helicobacter pylori adherence to gastric mucosa cells in children and adults. An ultrastructural study

BACKGROUND

Infection with Helicobacter pylori in childhood may be the initiation of a lifelong coexistence between microorganisms and epithelial cells resulting in chronic inflammation. The adhesion pattern of H. pylori found in antral biopsies from a group of H. pylori-infected children with recurrent abdominal pain was compared with a group of H. pylori-infected adults suffering from dyspepsia, in an attempt to reveal differences in the type of adhesion.

METHODS

The histology of antrum biopsies and the ultrastructure of adherent H. pylori in biopsies from 26 children (median age, 10.1 years) were compared with organisms in biopsies from 19 adults (median age, 54.4 years).

RESULTS

More than 1000 adherent H. pylori were studied and divided into four types of adhesion: 1) contact to microvilli; 2) connection to the plasma membrane via filamentous material; 3) adhesive pedestal formation; and 4) abutting or making a depression in the plasma membrane. Contact to microvilli was significantly higher (69% versus 39%; P = 0.002) in children compared with adults and comprised two-thirds of all adherent organisms in children. The more intimate adhesion types as abutting or adhesive pedestals dominated in adults.

CONCLUSIONS

These results indicate a change in contact types between H. pylori and gastric epithelial cells in adults compared with children and this may be a natural development in the lifelong infection of humans.

Mucosa-associated lymphoid tissue lymphoma with initial supradiaphragmatic presentation: natural history and patterns of disease progression

PURPOSE

Mucosa-associated lymphoid tissue (MALT) lymphoma commonly presents in the gastrointestinal (GI) tract. Supradiaphragmatic MALT lymphoma is less common and its natural history is not well defined. This study was conducted to understand the natural history, to determine the frequency of synchronous disease in the GI tract, and to understand the patterns of disease progression after treatment for supradiaphragmatic MALT lymphoma.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of 39 patients who presented with supradiaphragmatic MALT lymphoma between 1991 and 1997.

RESULTS

The median age of patients was 58 years (range, 25-90 years) with 16 male and 23 female patients. The most common primary site was salivary gland followed by ocular adnexa, lung, oral cavity, and others. Sixteen patients underwent esophagogastroduodenoscopy and biopsy (EGD + Bx) and 4 were found to have gastric involvement. Ann Arbor stages were the following: IEA, 17; IIEA, 5, IIEB, 1; and IVA, 16. The initial treatments were: involved field radiation therapy (n = 10), chemotherapy (n = 14), combination of radiation therapy and chemotherapy (n = 9), observation after biopsy (n = 4), antibiotics only (n = 1), and patient refusal of further intervention (n = 1). Seven patients received antibiotics as a part of the initial treatment. Every patient except for 1 was alive at a median follow-up of 39.5 months (range, 3-83 months). Thirty-six patients achieved complete response (CR) to the initial treatment. The actuarial 5-year progression-free survival rate was 83%. Progression of the disease occurred in 4 patients, with 2 in the stomach. Salvage attempts were made to 4 and were successful in 3. Of the 2 patients who relapsed in the stomach, 1 had negative EGD + Bx at the time of initial diagnosis. An EGD + Bx was not done in the second patient.

CONCLUSION

Supradiaphragmatic MALT lymphoma appears to have a favorable prognosis. However, routine evaluation of the stomach is recommended for patients who present with supradiaphragmatic MALT lymphoma at the time of initial evaluation and at the time of relapse. Patients who failed initial therapy can be successfully salvaged with further treatment.

Malignant tumors of the stomach. Gastric mucosa-associated lymphoid tissue lymphoma and Helicobacter pylori

With the help of many clinical studies, the diagnosis and therapy of gastric MALT lymphoma have evolved. Major progress has been seen in this area, including improvement of biopsy diagnosis, better histologic classification, new information concerning pathogenesis, and, especially, the start of a revolution in the treatment of low-grade gastric MALT lymphomas by eradicating H. pylori. About 12 clinical studies with almost 400 patients and case reports have shown that cure of H. pylori infection is associated with complete remission in approximately 80% of patients with low-grade MALT lymphoma in an early clinical stage. To establish H. pylori eradication as the primary choice in low-grade gastric MALT lymphoma further, it is necessary to select patients before therapy who are most likely to benefit from this single treatment modality. An excellent histologic workup of obtained biopsy specimens and comprehensive clinical staging are necessary. Because of the supposition that H. pylori-related growth support may play a role only in the early stages of low-grade gastric MALT lymphoma, the importance of determining the depth of lymphoma infiltration in the gastric wall is evident. Examinations by endosonographic ultrasonography have been shown to be the most reliable method to differentiate the layers of the gastric wall and to determine the infiltration depth of lymphomas. Eradication of H. pylori has to be considered as a first-line and single treatment modality in patients with low-grade gastric MALT lymphoma in clinical stage EI1. As a therapy with fewer side effects than radiation, surgery, or chemotherapy and as a stomach-conserving treatment, eradication of H. pylori in patients with low-grade gastric MALT lymphoma should be the treatment of the choice within clinical trials because there are no long-term results available thus far. Besides pretreatment patient selection, careful follow-up with endoscopy, biopsies, and clinical staging including endoscopic ultrasonography is necessary. A 5- to 10-year follow-up is necessary before the definitive value of H. pylori eradication can be established, but long-term results are excellent thus far. There are many questions to be addressed: What are the exact mechanisms that lead to the malignant transformation of a reactive infiltrate? Why do approximately 20% of low-grade MALT lymphomas not regress after H. pylori eradication? Is there a molecular-genetic or immunologic point of no return? What is the biologic significance of the immunoglobulin rearrangement detected with PCR? What will be the 5- and 10-year relapse-free survival rates of patients suffering from low-grade MALT lymphoma treated with H. pylori eradication alone as first and only treatment? The wave of new data each year about the role of H. pylori in gastric MALT lymphoma may help many of these questions to be answered.

Role of strain type, AGS cells and fetal calf serum in Helicobacter pylori adhesion and invasion assays

In a human gastric biopsy specimen, 30% of adhering Helicobacter pylori strain AF4 (cagA and VacA positive) was associated with adhesion pedestals. In an AGS cell assay, only a few percent of this type I strain was found to be associated with adhesion pedestals. Nevertheless, a larger proportion of the type I strain was found to invade AGS cells (P < 0.03) and to attach with depressions in the AGS cell membrane (P < 0.03) than a type II strain (cagA and VacA negative). Incubation of AGS cells and H. pylori without adding fetal calf serum (FCS) to the culture medium increased actin accumulations (FITC-phalloidin stained) beneath adhering H. pylori, and decreased H. pylori invasion of AGS cells significantly (P < 0.01). However, no increase in the number of adhesion pedestals was observed by electron microscopy. Proteinase K treatment of FCS eliminated the H. pylori invasion promoting effect (P < 0.01). Our results suggest differences in the ability of H. pylori to induce adhesion pedestals in human gastric epithelial cells and in AGS cells, but a correlation between adhesion pedestal formation in vivo and H. pylori invasion in vitro can be speculated. In addition, H. pylori invasion into AGS cells was found to be mediated by proteins in FCS.

Helicobacter pylori eradication: proton pump inhibitor vs. ranitidine bismuth citrate plus two antibiotics for 1 week-a meta-analysis of efficacy

OBJECTIVE

To compare the efficacy of proton pump inhibitor vs. ranitidine bismuth citrate (RBC) with two antibiotics for 1 week in Helicobacter pylori eradication.

METHODS

Randomized trials comparing 1-week regimens with (i) proton pump inhibitor plus two antibiotics [clarithromycin (C) and amoxycillin (A) or a nitroimidazole (N)]; or (ii) RBC plus the same antibiotics. Eradication was confirmed by histology or 13C-urea breath test at least 4 weeks after therapy. Data sources included PubMed database and abstracts from congresses until October 1999. Statistical analysis was by meta-analysis combining the odds ratios (OR) of the individual studies in a global OR (Peto method).

RESULTS

Twelve studies met the selection criteria. Nine compared proton pump inhibitor vs. RBC plus C and A, and five compared proton pump inhibitor vs. RBC plus C and N. With RBC, C and A, mean H. pylori eradication efficacy by intention-to-treat analysis (pooled data) was 76.6% (95% CI: 72-81%) and 73.7% (95% CI: 69-78%) with proton pump inhibitor, C and A. The OR for the effect of RBC vs. proton pump inhibitor (plus C and A) on H. pylori eradication was 1.15 (95% CI: 0.8-1.64%). Mean H. pylori eradication with RBC, C and N was 87. 2% (95% CI: 83-91%), and 74.9% (95% CI: 74-84%) with proton pump inhibitor plus these two antibiotics. The OR for the effect of RBC vs. proton pump inhibitor (plus C and N) on H. pylori eradication was 1.76 (95% CI: 1.08-2.85%).

CONCLUSION

RBC and proton pump inhibitor have similar efficacy for H. pylori eradication when given with C and A for 1 week, but RBC seems to have a higher efficacy than proton pump inhibitor when C and N are the co-prescribed antibiotics.