抄録
Recently, it has been accepted that Helicobacter pylori (H. pylori) isolated from the gastric mucosa of patients with gastritis in 1983 is highly associated with low-grade gastric lymphoma arising from mucosa-associated lymphoid tissue (L-MALToma). In fact, L-MALToma has been shown to be associated with H. pylori infection in more than 90% of cases. Furthermore, several recent reports demonstrated the regression of L-MALToma after H. pylori eradication with high frequency, although a definite conclusion has not been drawn due to the limited number of cases. Our eradication study also supports this phenomenon. We analyzed the outcome in 20 H. pylori-infected patients with L-MALToma after H. pylori eradication endoscopically, histologically and genetically. Thirteen our of 20 cases (65%) showed changes to chronic gastritis histologically and the mean period until this response was 2.8 months. The endoscopic findings also improved in 12 out of these 13 cases. Althogh 9 cases only showed a monoclonal pattern of IgH and 4 changed to a polyclonal pattern, all of these are responders. These results suggest that H. pylori eradication should be recommended initially for clinical management of L-MALToma, because rapid improvement can be expected. During the follow-up of these patients, however, 3 cases showed the regrowth of lesions and were diagnosed again as L-MALToma histologically. Furthermore, L-MALToma is sometimes invasive and disseminates to regional lymph node, bone marrow and other organs. Therefore, besides the informed consent required from the patients before treatment, the close follow-up using endoscopic examination every 3 months and systemic CT examination every 6 months are needed even if endoscopic biopsy reveals chronic gastritis histologically.
