Immunophenotyping in the management of gastric lymphoma

Flow cytometric analysis of kappa and lambda light chain expression in endoscopic biopsy specimens before the diagnosis of B-cell lymphoma

Forty-eight patients with gastrointestinal (GI) tract B-cell lymphoma (BCL) were analyzed retrospectively. The diagnosis was based on the histological examination of specimens obtained by endoscopic biopsy. Before the diagnosis was made, single-color flow cytometry was performed to analyze the expression of light chains and B-cell antigens including CD10 in the specimens. Restricted light chain (RLC) expression, a marker of B-cell clonality, was defined as κ and λ ratios of either more than 3.0 or less than 0.5. The specimens from 30 patients (62.5%) showed RLC expression. No RLC expression or RLC expression not examined was divided into two groups : those showing CD10 positivity in more than 20% of cells (4 patients, 8.3%) and those showing no positivity (14 patients, 29.2%). The cell number analyzed in the latter group was significantly smaller than that in the other two groups. Abnormal karyotypes were found in the specimens from 8 patients (16.7%). These results indicate that the flow cytometric analysis of endoscopic biopsy specimens is useful when BCL is suspected if an adequate number of cells are obtained.

Preoperative versus intraoperative endoscopic sphincterotomy for management of common bile duct stones

BACKGROUND

ERCP remains the prevailing method of treating CBDS; however, its ideal timing in respect to laparoscopic cholecystectomy (LC) is not defined. LC combined with intraoperative endoscopic sphincterotomy (IOES) was compared with preoperative endoscopic sphincterotomy (PES) followed by LC for management of preoperatively known cholecystocholedocholithiasis.

METHODS

Between June 2006 and September 2009, 198 patients diagnosed preoperatively by clinical assessment, liver chemistry, ultrasonography, and magnetic resonance cholangiopancreatography (MRCP) to have combined choledochocystolithiasis were eligible. They were randomly divided into two groups: PES/LC group (n = 100) and LC/IOES group (n = 98). The surgical times, surgical success rates, number of stone extractions, postoperative complications, retained common bile duct stones, and postoperative lengths of stay were compared prospectively.

RESULTS

There were no statistically significant differences in surgical time, surgical success rate, CBD diameter, stone size, or stone number between the two groups. The success rate was 95.3% and 97.8% for PES/LC and LC/IOES, respectively. There were no significant difference in postoperative retained stones, surgical time, and complications, but the total hospital stay was significantly shorter in the LC/IOES group.

CONCLUSIONS

PES/LC and LC/IOES are both good options for dealing with preoperatively diagnosed CBDS, but when there is enough experience and facilities, LC/IOES, as a single-stage treatment, would be preferable.

Helicobacter pylori infection in children

A number of scientific breakthroughs since H pylori first became recognized as a human pathogen have increased our understanding of the pathogenesis of gastroduodenal disease. In particular, advances in molecular bacteriology and the complete sequencing of the H pylori genome in 1999, and soon thereafter the human genome, provide tools allowing better delineation of the pathogenesis of disease. These molecular tools for both bacteria and host should now be applied to multicenter pediatric studies that evaluate disease outcome. More recent developments indicate that a better understanding of the microbial-host interaction is critical to furthering knowledge with respect to H pylori-induced diseases. Studies are needed to evaluate either DNA-based or more traditional protein-based vaccines, to evaluate more specific antimicrobials that confer minimal resistance, and to evaluate probiotics for the management of H pylori infection. Multicenter multinational studies of H pylori infection in the pediatric population, which include specific, randomized controlled eradication trials, are essential to extend current knowledge and develop better predictors of disease outcome.

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.

A comprehensive review of the natural history of Helicobacter pylori infection in children

Across populations of children, Helicobacter pylori prevalence ranges from under 10% to over 80%. Low prevalence occurs in the U.S., Canada, and northern and western Europe; high prevalence occurs in India, Africa, Latin America, and eastern Europe. Risk factors include socioeconomic status, household crowding, ethnicity, migration from high prevalence regions, and infection status of family members. H. pylori infection is not associated with specific symptoms in children; however, it is consistently associated with antral gastritis, although its clinical significance is unclear. Duodenal ulcers associated with H. pylori are seldom seen in children under 10 years of age. H. pylori-infected children demonstrate a chronic, macrophagic, and monocytic inflammatory cell infiltrate and a lack of neutrophils, as compared with the response observed in adults. The effect of H. pylori infection on acid secretion in children remains poorly defined. The events that occur during H. pylori colonization in children should be studied more thoroughly and should include urease activity, motility, chemotaxis, adherence, and downregulation of the host response. The importance of virulence determinants described as relevant for disease during H. pylori infection has not been extensively studied in children. Highly sensitive and specific methods for the detection of H. pylori in children are needed, especially in younger pediatric populations in which colonization is in its early phases. Criteria for the use of eradication treatment in H. pylori-infected children need to be established. Multicenter pediatric studies should focus on the identification of risk factors, which can be used as prognostic indicators for the development of gastroduodenal disease later in life.

Primary Gastric Lymphoma

BACKGROUND: Gastric lymphoma is a common presentation of non-Hodgkin's lymphoma. Controversy reigns about many aspects of its classification and management, especially regarding roles for surgical resection. METHODS: The authors review the clinical features, staging, pathology, prognosis, and management issues with an emphasis on the role of surgical resection. RESULTS: Staging usually can be completed using noninvasive techniques. Those with a low-grade B-cell MALT type lymphoma with Helicobacter pylori infection may be treated with antibiotics and close follow-up. Patients with stage I or II disease may be treated with chemotherapy and radiation. Surgery is indicated for those with perforation or uncontrolled bleeding. CONCLUSIONS: Gastric lymphoma, primarily a B-cell tumor, can be diagnosed and managed effectively with various approaches. Few prospective, randomized trials of alternative approaches have been performed.

A clinicopathologic study of 233 cases with special reference to evaluation with the MIB-1 index

BACKGROUND

Few articles have analyzed the prognostic data from a large series of primary gastric lymphoma classified according to the concept of mucosa-associated lymphoid tissue (MALT).

METHODS

The resected specimens from 233 patients with primary gastric lymphoma were investigated retrospectively, including immunostaining with MIB-1 (Ki-67).

RESULTS

Histologically, 70 (30%) of the cases were low grade B-cell lymphoma of MALT, 27 (12%) low grade B-cell lymphoma of MALT with a focal high grade component, 100 (43%) high grade B-cell lymphoma of MALT, 15 (6%) other B-cell lymphomas, 14 (6%) T-cell lymphomas, and 7 (3%) undetermined. Macroscopically, 96 (41%) were superficial-spreading type, 100 (43%) mass-forming, 14 (6%) diffuse-infiltrating, and 23 (10%) unclassified. The MIB-1 index correlated with phenotype, histologic grade, stage, depth of invasion, and macroscopic type. A significantly better survival was noted for young patients, and those with tumors of a B-cell phenotype, histologic low grade, macroscopic superficial-spreading type, low stage, low depth of invasion, and low MIB-1 index. No significantly different survival rates were found between the patients who underwent gastric resection alone and those who also received additional chemotherapy. By Cox multivariate analysis, independent prognosticators included B-cell phenotype, low stage, and macroscopic superficial-spreading type.

CONCLUSIONS

In addition to stage, phenotype and macroscopic type are also important prognostic indicators of primary gastric lymphoma. Immunostaining with MIB-1 had limited independent value for predicting prognosis.

Helicobacter pylori infection and gastric lymphoma

BACKGROUND

Helicobacter pylori infection is a risk factor for gastric adenocarcinoma. We examined whether this infection is also a risk factor for primary gastric non-Hodgkin's lymphoma.

METHODS

This nested case-control study involved two large cohorts (230,593 participants). Serum had been collected from cohort members and stored, and all subjects were followed for cancer. Thirty-three patients with gastric non-Hodgkin's lymphoma were identified, and each was matched to four controls according to cohort, age, sex, and date of serum collection. For comparison, 31 patients with nongastric non-Hodgkin's lymphoma from one of the cohorts were evaluated, each of whom had been previously matched to 2 controls. Pathological reports and specimens were reviewed to confirm the histologic type of the tumor. Serum samples from all subjects were tested for H. pylori IgG by an enzyme-linked immunosorbent assay.

RESULTS

Thirty-three cases of gastric non-Hodgkin's lymphoma occurred a median of 14 years after serum collection. Patients with gastric lymphoma were significantly more likely than matched controls to have evidence of previous H. pylori infection (matched odds ratio, 6.3; 95 percent confidence interval, 2.0 to 19.9). The results were similar in both cohorts. Among the 31 patients with nongastric lymphoma, a median of six years had elapsed between serum collection and the development of disease. No association was found between nongastric non-Hodgkin's lymphoma and previous H. pylori infection (matched odds ratio, 1.2; 95 percent confidence interval, 0.5 to 3.0).

CONCLUSIONS

Non-Hodgkin's lymphoma affecting the stomach, but not other sites, is associated with previous H. pylori infection. A causative role for the organism is plausible, but remains unproved.

Role of surgery in patients with primary non-Hodgkin's lymphoma of the stomach: an old problem revisited

The literature after 1980 dealing with the treatment of primary gastric non-Hodgkin's lymphoma (stages I and II) is reviewed. Gastrectomy is recommended for patients with acute symptoms at presentation or with complications of chemotherapy or radiotherapy. In elective cases, patients with stage I disease may be candidates for gastrectomy as a single therapy, provided that tumour-free resection margins are achieved. There is no evidence of substantial benefit from adding postoperative chemotherapy or radiotherapy after an apparently radical resection. In stage II disease, the best results are achieved with ablative surgery plus adjuvant therapy. The resection volume should be limited to macroscopically involved structures, in principle avoiding total gastrectomy and extensive lymph node dissection, since residual disease may be optimally controlled with radiotherapy or chemotherapy. Primary chemotherapy, with or without radiotherapy, represents an experimental approach; the advantages of sparing the stomach must be balanced against the toxicity of an aggressive chemotherapy regimen and the risk of emergency operation for iatrogenic complications.

Gastric lymphoma treatment. Medical versus surgical

The treatment of gastric lymphoma is an area of ongoing controversy. Surgical resection has been the standard therapy. Recent advances, however, have been developed in other treatment modalities. A comparison of treatment options is presented.