Analysis of Helicobacter pylori Infection Status and Clarithromycin-resistant Strains in Patients With Gastric Mucosa-associated Lymphoid Tissue Lymphoma Using Real-time Polymerase Chain Reaction: A Single-center Korean Study.

Background: Helicobacter pylori (HP) is a well-known risk factor for gastric mucosa-associated lymphoid tissue (MALT) lymphoma. However, the prevalence of clarithromycin-resistant (CLR) HP strains in patients with gastric MALT lymphoma compared with the general population is largely unknown.

Materials And Methods: HP test was performed on samples from 4686 patients who underwent gastric biopsy, including 89 patients who were diagnosed with gastric MALT lymphoma. HP infection and resistant strains (A2142G and A2143G) were investigated using real-time polymerase chain reaction.

Results: HP was detected in 1964 out of 4597 cases in the non-MALT control group (42.7%), while HP infection was present in 51 out of 89 cases (57.3%) in the gastric MALT lymphoma group (P=0.006). The frequency of CLR strains was 39.2% (20 out of 51 cases) in the gastric MALT lymphoma group, which was significantly higher than the rate of 26.8% (527 out of 1964 cases) in the non-MALT control patient group (P=0.049). The proportion of the resistant strain A2142G was higher in the gastric MALT lymphoma group (20.0%, 4/20) than in the non-MALT control patient group (11.0%, 58/527), with marginal statistical significance (P=0.093).

Conclusions: The significantly higher infection rate of CLR HP in patients with gastric MALT lymphoma suggests a reduced likelihood of successful tumor regression using clarithromycin-based first-line eradication therapy.