Rapidly progressive Epstein-Barr virus-associated lymphoproliferative disorder unpredictable by weekly viral load monitoring.

We report a case of Epstein-Barr virus (EBV)-associated lymphoproliferative disease (LPD) following unrelated bone marrow transplantation (UBMT) for severe aplastic anemia treated with a conditioning regimen that included anti-thymocyte globulin (ATG). The patient showed signs of EBV reactivation as early as 34 days after UBMT. Our weekly schedule for EBV monitoring failed to trace rapid changes in EBV viral load and the patient eventually developed EBV-LPD. However, early intervention with monoclonal antibody against CD20, rituximab, stopped the further progression of EBV-LPD. As several recent reports have suggested, the safety and efficacy of rituximab treatment for EBV-LPD is supported by our limited experience with post transplant EBV-LPD.