TREATMENT OF LOW-GRADE GASTRIC MALT LYMPH OMA WITH HELICOBACTER-PYLORI ERADICATION - FOLLOW-UP OF THE HISTOLOGICAL AND MOLECULAR RESPONSE

BACKGROUND: LOW grade gastric MALT lymphoma is associated to infection with Helicobacter pylori. Also, H. pylori eradication can produce his tologic regression of the lymphoma. PATIENTS AND METHODS: This study r eports the follow-up of a prospective series of 11 patients with low g rade gastric MALT lymphoma, stage I, treated with eradicative therapy for H. pylori. After treatment, patients were followed up with sequent ial endoscopies to asses the histological and molecular regression of the lymphoma, using a score of the histological lesions and the amplif ication of the IgH gene with PCR analysis. RESULTS: Helicobacter pylor i was eradicated in all patients. In 10 (90.9%) histological regressio n of the lymphoma was demonstrated, in 6 of them in the first control after treatment. In the 10 patients with histological response, PCR an alysis demonstrated a polyclonal rearrangement of the IgH gene in 6 (6 0%) and a clonal band in 4 (40%), that eventually disappeared at 12 (S D 4) months after treatment. In 4 patients with a previous polyclonal rearrangement, a clonal band was occasionally detected in any sequenti al controls; in 2 of these cases the clonal band disappeared 5 and 7 m onths after treatment and in the remaining 2 its evolution is not yet known. Nine patients have been followed up and are in remission 18 (SD 8) months after treatment. CONCLUSIONS: Eradication of H. pylori can produce histologic regression in stage I low grade gastric MALT lympho ma, and should be the first therapeutic option. Despite histological r egression of the lymphoma, PCR analysis can detect a clonal rearrangem ent of the IgH gene in 40% of the cases, but its significance remains unknowm. Sequential and prolonged follow-up is essential to assess whe ther this lymphoma can be actually cured with eradication therapy for H. pylori.