Objectives: Mucosa-associated lymphoid tissue (MALT) can develop in gastric mucosa after Helicobacter pylori infection, but not all H. pylori-positive patients develop acquired MALT, probably because of different levels of individual susceptibility against H. pylori-antigens. Our aim was to conduct long-term follow-up in MALT-positive and MALT-negative patients after H. pylori had been eradicated to determine what happens after H. pylori reinfection.
Methods: We studied 30 H. pylori-positive patients, 15 MALT-positive patients (group A), and 15 MALT-negative patients (group B). After the eradication of H. pylori and disappearance of acquired MALT in group A, follow-up was conducted by repeated endoscopic biopsies every 4-6 months for a mean period of 30.6 months (31.6 months for group A, 29.4 for group B).
Results: During follow-up, three group A patients were reinfected by H. pylori, and MALT recurred. Moreover, in each patient, it was the same grade of acquired MALT that had previously been diagnosed (grade 2 in two patients and grade 3 in one). A second course of anti-H. pylori treatment resulted both in eradication of H. pylori and the disappearance of MALT. Conversely, none of the group B patients with H. pylori reinfection developed MALT. However, in those patients, too, a second course of treatment eradicated the H. pylori.
Conclusions: Our study shows that acquired MALT appears after reinfection with H. pylori only in patients who previously had that condition. Moreover, the grade of acquired MALT that reappears is the same as previously diagnosed. These findings demonstrate that not only H. pylori infection but also individual susceptibility may be important in determining both the presence of acquired MALT and its grade. However, strict follow-up is not advisable in MALT-positive patients, because no patient developed MALT-lymphoma during follow-up.