Helicobacter heilmannii-associated primary gastric low-grade MALT lymphoma:: Complete remission after curing the infection

Background & Aims: Cure of Helicobacter pylori infection may lead to complete remission of associated low-grade mucosa-associated lymphoid tissue (MALT) lymphoma in stage El. This study investigated whether Helicobacter heilmannii infection-associated primary gastric MALT lymphoma will regress after cure of the infection. Methods: H. heilmannii-induced gastritis was diagnosed histologically, by a new specific immunoglobulin G enzyme-linked immunosorbent assay, and with 16S ribosomal RNA amplification and sequencing in 5 consecutive patients with primary gastric MALT lymphoma clinical stage El. Patients received 40 mg omeprazole and 750 mg amoxicillin 3 times per day for 14 days. Polymerase chain reaction (PCR) was used to detect rearrangement of immunoglobulin heavy-chain genes before treatment and during follow-up. Results: Five patients (3 men, 2 women; mean age, 65 years; range, 42-79 years) were studied. H. pylori was not detected by culture, histology, serology, or PCR. Treatment resulted in the cure of H. heilmannii infection in each case and complete histological and endoscopic remission of the tumors. Three of 5 patients showed monoclonal B cells before treatment, 2 of whom remained PCR positive. Within a median follow-up period of 24 months, no relapse of the lymphoma or reinfection with H. heilmannii occurred. Conclusions: These data suggest that gastric MALT lymphoma may arise in patients with H. heilmannii infection. Cure of this infection may lead to complete remission of the MALT lymphoma.