Anti-CD20 antibody (rituximab) administration in patients with late occurring lymphomas after solid organ transplant.

Background And Objectives: Aggressive diffuse large cell non-Hodgkin's lymphoma (DLCL) occurring late after a solid organ transplant fails to regress after discontinuation of immunosuppression. Moreover, chemotherapy treatment is associated with a high mortality rate due to severe toxicity. Since the majority of post-transplant lymphoproliferative disorders derive from B-lineage lymphocytes, the administration of anti-B monoclonal antibodies represents a rational therapeutic option.

Design And Methods: Five patients who developed CD20-positive DLCL more than two years after heart or liver transplantation were treated with a weekly chemotherapy program (2 patients), radiotherapy (2 patients) and surgery (1 patient) followed by a minimum of 4 intravenous doses of rituximab (375 mg/m(2)).

Results: A favorable clinical outcome was observed in three patients in whom surgery or radiotherapy had produced significant tumor debulking. Only a partial clinical effect was documented in the two patients with advanced clinical stage disease.

Interpretation And Conclusions: Rituximab can be safely administered to patients with aggressive CD20-positive DLCL occurring late after a solid organ transplant. However, a positive clinical outcome may be expected only in patients in whom surgery or radiotherapy has achieved significant regression of tumor burden.