Serum antibodies to Helicobacter pylori and its heat-shock protein 60 correlate with the response of gastric mucosa-associated lymphoid tissue lymphoma to eradication of H. pylori

Background and aims. Eradication of Helicobacter pylori leads to regression of mucosa‐associated lymphoid tissue (MALT) lymphomas. In this study, we measured serum antibodies to H. pylori and H. pylori‐recombinant heat‐shock protein 60 (rHSP60) in patients with gastric MALT lymphoma to determine whether humoral immune responses to the bacterial antigens correlate with the efficacy of eradication therapy. Methods. Serum samples were obtained from 33 patients with H. pylori‐positive gastric MALT lymphoma before undergoing therapy to eradicate the bacteria. Anti‐H. pylori antibodies were measured in a commercial assay and in immunoassays to lysates and rHSP60 which were prepared from ATCC 43504 strain. Results. Helicobacter pylori were eradicated in all 33 patients, and the lymphoma completely regressed histologically in 26 patients (79%). Pre‐treatment titers of serum antibody to H. pylori and to rHSP60 in the patients whose tumor regressed were significantly higher than titers in patients whose tumors did not regress (p = .0011 and .035, respectively). By logistic regression analysis, age (odds ratio = 0.88, 95% confidence interval = 0.80–0.99), endoscopic appearance (0.053, 0.004–0.65), titers of anti‐H. pylori antibodies (67.6, 2.5–1800), and titers of anti‐rHSP60 antibody (6.4, 1.2–36) were identified as significantly associated factors with the outcome of MALT lymphoma. Conclusions. Measurement of serum antibodies to H. pylori and HSP60 might be useful for predicting the response of gastric MALT lymphoma to eradication of H. pylori.