Treatment of gastric MALT lymphoma with a focus on Helicobacter pylori eradication

Diagnosis and Treatment for Gastric Mucosa-Associated Lymphoid Tissue (MALT) Lymphoma

Mucosa-associated lymphoid tissue (MALT) lymphoma, which was first reported in 1984, shows an indolent clinical course. However, the detailed clinicopathological characteristics of gastric MALT lymphoma have not been fully elucidated. We performed a literature search concerning the clinical features and treatment for gastric MALT lymphoma using PubMED. MALT lymphomas develop in single or multiple extranodal organs, of which the stomach is one of the most frequent sites; gastric MALT lymphoma accounts for 7% to 9% of all B-cell lymphomas, and 40% to 50% of primary gastric lymphomas. The eradication of Helicobacter pylori (H. pylori) is the first-line treatment for patients with gastric MALT lymphoma, regardless of the clinical stage. Approximately 60-90% of cases with stage I/II₁ disease only achieve a complete histological response via H. pylori eradication. In patients who do not respond to H. pylori eradication therapy, second-line treatments such as watch-and-wait, radiotherapy, chemotherapy, rituximab immunotherapy, and/or a combination of these are recommended. Thus, H. pylori plays a causative role in the pathogenesis of gastric MALT lymphoma, and H. pylori eradication leads to complete histological remission in the majority of cases.

A Novel Synthetic Compound, Bismuth Zinc Citrate, Could Potentially Reduce Cisplatin-Induced Toxicity Without Compromising the Anticancer Effect Through Enhanced Expression of Antioxidant Protein

Cisplatin is a common anticancer drug, but it comes with significant nephrotoxicity. Further cisplatin-induced oxidative stress contributes to the pathogenesis of the nephrotoxicity. A new compound, BiZn, can potentially prevent this complication. We verified our postulation by in vitro and in vivo models. From our findings, BiZn did not affect cisplatin-induced cytotoxicity on neuroblastoma cells under both in vitro and in vivo settings. However, BiZn significantly reduced the blood urea nitrogen and creatinine levels in cisplatin-treated mice. Under the lethal dosage of cisplatin, co-treatment of BiZn significantly increased the survival rate. BiZn stimulated antioxidant proteins metallothionein (MT) and glutathione (GSH) generation from kidney cells and minimized cisplatin-induced apoptosis. Knocking down MT-IIA and inhibiting GSH abolished such protection. In conclusion, pretreatment of BiZn decreased cisplatin-induced renal toxicity without affecting its antitumor activity. BiZn-induced antioxidant proteins MT and GSH may contribute to the renal protection effect.

Human Lysozyme Synergistically Enhances Bactericidal Dynamics and Lowers the Resistant Mutant Prevention Concentration for Metronidazole to Helicobacter pylori by Increasing Cell Permeability

Metronidazole (MNZ) is an effective agent that has been employed to eradicate Helicobacter pylori (H. pylori). The emergence of broad MNZ resistance in H. pylori has affected the efficacy of this therapeutic agent. The concentration of MNZ, especially the mutant prevention concentration (MPC), plays an important role in selecting or enriching resistant mutants and regulating therapeutic effects. A strategy to reduce the MPC that can not only effectively treat H. pylori but also prevent resistance mutations is needed. H. pylori is highly resistant to lysozyme. Lysozyme possesses a hydrolytic bacterial cell wall peptidoglycan and a cationic dependent mode. These effects can increase the permeability of bacterial cells and promote antibiotic absorption into bacterial cells. In this study, human lysozyme (hLYS) was used to probe its effects on the integrity of the H. pylori outer and inner membranes using as fluorescent probe hydrophobic 1-N-phenyl-naphthylamine (NPN) and the release of aspartate aminotransferase. Further studies using a propidium iodide staining method assessed whether hLYS could increase cell permeability and promote cell absorption. Finally, we determined the effects of hLYS on the bactericidal dynamics and MPC of MNZ in H. pylori. Our findings indicate that hLYS could dramatically increase cell permeability, reduce the MPC of MNZ for H. pylori, and enhance its bactericidal dynamic activity, demonstrating that hLYS could reduce the probability of MNZ inducing resistance mutations.

Helicobacter pylori and colorectal neoplasia: Is there a causal link?

Ever since Helicobacter pylori (H. pylori) was recognized as an infectious cause of gastric cancer, there has been increasing interest in examining its potential role in colorectal carcinogenesis. Data from case-control and cross-sectional studies, mostly relying on hospital-based samples, and several meta-analyses have shown a positive statistical relationship between H. pylori infection and colorectal neoplasia. However, the possibility exists that the results have been influenced by bias, including the improper selection of patients and disparities with respect to potential confounders. While the evidence falls short of a definitive causal link, it appears that infection with H. pylori/H. pylori-related gastritis is associated with an increased, although modest, risk of colorectal adenoma and cancer. The pathogenic mechanisms responsible for this association remain uncertain. H. pylori has been detected in colorectal malignant tissues; however, the possibility that H. pylori is a direct activator of colonic carcinogenesis remains purely hypothetical. On the other hand, experimental data have indicated a series of potential oncogenic interactions between these bacteria and colorectal mucosa, including induction and perpetuation of inflammatory responses, alteration of gut microflora and release of toxins and/or hormonal mediators, such as gastrin, which may contribute to tumor formation.

Chronic inflammation: is it the driver or is it paving the road for malignant transformation?

Chronic inflammation in well-defined mouse models such as Giα2 knock out mouse has been shown to trigger formation and expansion of hypoxic niches and also leads to up regulation of NFĸB, offering cells which have adapted their genetic machinery to hypoxia a unique survival advantage. These adapted cells have been shown to acquire stem cell-like capabilities as shown by up regulation of stem cell markers. Such long lived cells become permanent residents in sub mucosa and acquire a malignant phenotype from long-term exposure to noxious environmental agents due to a barrier defect secondary to down regulation of barrier proteins such as Zo1 and Occludin. Indeed mitotic spindle disorientation in such mice has been proposed as another contributory factor to malignant transformation. Sterilization of bowel lumen of these mice through different techniques has prevented malignant transformation in the presence of chronic inflammation. These facts stand strongly against chronic inflammation as a true driver of carcinogenesis but clearly support its role in facilitating the emergence of the neoplastic clone.

Flavonoid Glycosides of Polygonum capitatum Protect against Inflammation Associated with Helicobacter pylori Infection

The antibacterial and anti-inflammatory activities, and protective effects of extracts (flavonoid glycosides) of Polygonum capitatum were investigated to detect the evidence for the utilization of the herb in the clinical therapy of gastritis caused by H. pylori. A mouse gastritis model was established using H. pylori. According to treating methods, model mice were random assigned into a model group (MG group), a triple antibiotics group (TG group, clarithromycin, omeprazole and amoxicillin), low/middle/high concentrations of flavonoid glycosides groups (LF, MF and HF groups) and low/middle/high concentrations of flavonoid glycosides and amoxicillin groups (LFA, MFA and HFA groups). A group with pathogen-free mice was regarded as a control group (CG group). The eradicate rates of H. pylori were 100%, 93%, 89% in TG, MFA and HF groups. The serum levels of IFN-gamma and gastrin were higher in a MG group than those from all other groups (P < 0.05). The serum levels of IFN-gamma and gastrin were reduced significantly in LF, MF and HF groups (P < 0.05) while little changes were observed in LFA, MFA and HFA groups. In contrast, the serum levels of IL-4 were lower and higher in MG and CG groups compared with other groups (P<0.05). The serum levels of IL-4 were increased significantly in LF, MF and HF groups (P < 0.05) while little changes were found in LFA, MFA and HFA groups. According to pathological scores, flavonoid glycosides therapy showed better protection for gastric injuries than the combination of flavonoid glycoside and amoxicillin (P < 0.05). The results suggested that flavonoid glycoside has repairing functions for gastric injuries. The results suggest that the plant can treat gastritis and protect against gastric injuries. The flavonoid glycosides from Polygonum capitatum should be developed as a potential drug for the therapy of gastritis caused by H. pylori.

Evaluation of the clinical characteristics and prognostic factors of gastrointestinal mucosa-associated lymphoid tissue (MALT) lymphoma

BACKGROUND AND AIM

This study was undertaken to evaluate the clinical characteristics, prognostic factors, and long-term outcomes of patients with mucosa-associated lymphoid tissue (MALT) lymphoma in the gastrointestinal (GI) tract.

METHODS

Clinical and pathological features of patients with MALT lymphoma in the GI tract, who were treated consecutively at Tianjin Medical University Cancer Institute and Hospital from 2001 to 2011, were evaluated retrospectively.

RESULTS

Among a total of 99 identified cases, 79.79% of lymphomas were localized in the stomach, 20.20% in the intestinal tract, and disseminated disease was detected in 35.4% of cases. The estimated 5-year overall survival (OS) and 5-year progression-free survival (PFS) rates were 73.1% and 65.1%, respectively. The comparison between stomach and intestinal tract lymphomas demonstrated no significant difference in characteristics, but nodal involvement was significantly lower in gastric MALT lymphoma (26.6%) as compared with intestinal tract MALT lymphoma (60%, P = 0.006). The outcomes of gastric and intestinal MALT lymphomas were similar (OS, P = 0.492; PFS, P = 0.408), and so was the survival between proximal and distal gastric lymphomas (OS, P = 0.077; PFS, P = 0.181). Serum lactate dehydrogenase level above normal was identified as the only adverse prognostic factor for both OS and PFS.

CONCLUSION

The clinical characteristics and outcomes demonstrated no significant differences between gastric and intestinal tract MALT lymphomas. Serum lactate dehydrogenase level was an independent prognostic factor for the survival of GI MALT lymphoma.

Treatment of Helicobacter pylori infection: meeting the challenge of antimicrobial resistance

Treatment of Helicobacter pylori (H. pylori) infection is paramount for the management of prevalent gastrointestinal disorders including peptic ulcer disease and gastric cancer. Due to the wide increase in prevalence of H. pylori resistance to antibiotics, clarithromycin-based triple therapies are not any more suitable for unconditional empiric use, and should not be recommended, unless local resistance to this antibiotic is low (< 20%). Alternative strategies have been proposed to overcome the issue of increasing clarithromycin resistance, and some of them are already implemented in clinical practice. These comprise: (1) adoption of novel, more effective, empirical treatments: bismuth quadruple, sequential, non-bismuth quadruple (concomitant), dual-concomitant (hybrid), and levofloxacin-based regimens, the latter mainly designated as second-line/rescue options; (2) perspectives for a susceptibility-guided (tailored) therapeutic approach based on culture-free molecular testing methods; and (3) adjunct use of probiotics to improve eradication rates. The present article is aimed to provide a comprehensive overview of current and emerging strategies in the treatment of H. pylori infection, focusing on the challenge of antimicrobial resistance.

MALT lymphoma of the small bowel with protein-losing enteropathy

Mucosa-associated lymphoid tissue (MALT) lymphoma usually arises from chronic inflammation. We herein report a case of small intestinal MALT lymphoma with protein-losing enteropathy (PLE). A 73-year-old woman presented with lower leg edema and severe hypoalbuminemia. She had a medical history of pylorus-preserving pancreaticoduodenectomy with Billroth II reconstruction. Oral and anal route double-balloon enteroscopies revealed irregular nodular mucosal lesions with erosion extending from the jejunum to terminal ileum. Histopathological evaluation of the biopsied mucosa showed proliferation of small-to-medium-sized lambda light chain-restricted B cells. Plasmacytic differentiation and lymphoepithelial lesions were present, leading to the diagnosis of MALT lymphoma. Tc-99m albumin scintigraphy indicated tracer exudation in the small bowel, suggesting the presence of PLE. Combination immunochemotherapy with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) regimen improved both MALT lymphoma and PLE, whereas rituximab monotherapy was not successful. This case is considered to be common type of MALT lymphoma at an uncommon site and is distinct from immunoproliferative small intestinal disease (IPSID). To our knowledge, this is the first case of non-IPSID-type small intestinal MALT lymphoma complicated by PLE. Gastrointestinal reconstruction may be responsible for underlying chronic inflammation via small intestinal bacterial overgrowth.