Treatment of gastric MALT lymphoma by Helicobacter pylori eradication: a study controlled by endoscopic ultrasonography.

OBJECTIVE: Previous studies have demonstrated a link between Helicobacter pylori infection and low grade B-cell gastric MALT lymphoma. The aim of this study was to evaluate the effect of Helicobacter pylori eradication in 17 patients with low grade B-cell gastric MALT lymphoma stage EI. METHODS: For disease staging EUS and CT scan were systematically performed. Eight patients were excluded from the present series because stage EII disease was diagnosed. To demonstrate B-cell monoclonality, immunohistochemistry and polymerase chain reaction were used. H. pylori eradication was performed with triple therapy. RESULTS: H. pylori was eradicated in all patients after first (n = 15) or second line (n = 2) treatment. Histologic regression of lymphoma was observed in all patients after a median period of 2 mo. Disappearance of monoclonality according to polymerase chain reaction took significantly longer (7 mo). At the end of the study, four of 16 patients still exhibited persistent monoclonal bands. Relapse of lymphoma occurred in two patients associated with H. pylori reinfection/recrudescence. CONCLUSION: Eradication of H. pylori seems to be an effective therapy in patients with stage EI gastric MALT lymphoma, although long-term results are still uncertain. Endoscopic ultrasonography is useful for a more accurate staging of the disease. The clinical significance of detecting monoclonality by polymerase chain reaction remains to be determined.

Effect of folate supplementation on DNA methylation of rectal mucosa in patients with colonic adenomas: correlation with nutrient intake.

We have evaluated the effect of folate supplementation (5 mg/day) on global deoxyribonucleic acid (DNA) methylation status of the rectal mucosa of 20 patients with resected colonic adenomas in a prospective, controlled, cross-over study. Baseline values of DNA methylation were inversely correlated with caloric (P = 0.03) and fat intake (P = 0.05) and patients harbouring multiple polyps consumed significantly more calories (P = 0.0006), fat (P = 0.009) and carbohydrates (P = 0.009) as compared to patients having one single lesion. Folate supplementation resulted in a significant decrease of DNA hypomethylation in 7/20 patients (P = 0.05) which returned to previous values after placebo treatment. This effect was significantly correlated with number of polyps, with all the responders presenting one single lesion, whereas 8/13 of the non-responders had multiple ones (chi2 = 7.17, P = 0.007). In conclusion, folate supplementation may decrease degree of DNA hypomethylation, but only in patients with one single polyp. In those with multiple lesions, other nutritional factors such as caloric and fat intake, may be more determinant.