Cytotoxic T cell-mediated gastritis after rituximab treatment for gastric malt lymphoma

T-Cell-Rich Recurrence of Primary Cutaneous Follicle Center Lymphoma After Systemic Rituximab: A Diagnostic Pitfall

We report on a 74-year-old man with a cutaneous B-cell follicle center lymphoma, which was treated upfront with systemic rituximab and suffered several local relapses. The first of the local recurrences, 10 months after completion of treatment, was characterized by a dense T-cell infiltrate that obscured a minor population of B-cell lymphoma cells, suggesting a second primary cutaneous T-cell lymphoma. This represents a previously not reported diagnostic pitfall and underscores the importance of performing sequential biopsies when dealing with lymphoma recurrences in this setting.

Skewing of the T-cell receptor repertoire in patients receiving rituximab after allogeneic hematopoietic cell transplantation: what lies beneath?

Rituximab is known to affect T cell immune responses. We and others have reported expansions of T large granular lymphocytes (T-LGLs) in lymphoma patients after Rituximab. We report here the immunogenetic profiling of the T cell receptor (TR) gene repertoire in 14 patients who received Rituximab post allo-HCT and explore clinicobiological correlations. All experienced antigenic triggers, CMV, EBV re-activation and chronic GvHD and had been treated with Rituximab. Skewing of TRBV genes was observed: 3 TRBV genes accounted for half of the repertoire. Oligoclonal pattern with expanded clonotypes was common. Patients with oligoclonality exhibited frequently cGvHD. Longitudinal samples in one revealed distinct clonotypes, suggesting clonal drift. T-LGL leukemia of donor origin with mixed chimerism eventually developed. In conclusion, we report development of oligoclonal T-LGLs after Rituximab post allo-HCT, alluding to antigen selection. Persistence of this phenomenon likely reflects strong antigenic stimulation by viruses and/or cGVHD aggravated by Rituximab.