Long-term persistence of monoclonal B cells after cure of Helicobacter pylori infection and complete histologic remission in gastric mucosa-associated lymphoid tissue B-cell lymphoma

Purpose: Cure of Helicobacter pylori infection is associated with remission induction in the majority of patients with low-grade gastric mucosa associ ated lymphoid tissue (MALT) lymphoma in localized stages; however, limited data exist as to whether these patients may be cured of their lymphoma. The present study was performed to investigate whether the polymerase chain re action (PCR) for the rearranged immunoglobulin heavy chain region may be us ed to define "molecular" remission. Patients and Methods: Ninety-seven patients who suffered from low-grade gas tric MALT lymphoma stage I, were observed with central pathology and molecu lar biology after cure of H Pylori infection. PCR was performed with the us e of consensus primers for the framework regions 1, 2, and 3 and monoclonal ity was corroborated by sequence analysis. In selected cases, microdissecti on was performed to study the origin of the monoclonal B cells. Results: Of the 97 patients, 77 obtained complete endoscopic and histologic remission (CR). Twenty of 44 patients with PCR monoclonality at diagnosis and with sufficient molecular follow-vp displayed monoclonal bands for a me dian time of 20.5 months after CR (range, 0 to 50.4 months). These B cells were related to the original lymphoma clone by sequence analysis. Microdiss ection analysis identified basal lymphoid aggregates as the source of these monoclonal B cells. Local relapse occurred in and was observed by PCR in f our patients. All four patients displayed monoclonal PCR before relapse, an d three of these four showed ongoing PCR monoclonality throughout their cou rse, indicating the persistence of malignant cells. Conclusion: Half of all patients with gastric MALT lymphoma show long-term PCR monoclonality up to several years after cure of H pylori infection and CR. Patients with monoclonal PCR should be observed closely, whereas long t erm PCR negativity may indicate cure of the disease. (C) 2001 by American S ociety of Clinical Oncology.