Response to Rituximab-Based Therapy and Risk Factor Analysis in Epstein Barr Virus—Related Lymphoproliferative Disorder After Hematopoietic Stem Cell Transplant in Children and Adults: A Study From the Infectious Diseases Working Party of the European Group for Blood and Marrow Transplantation

Background. The objective of this analysis was to investigate prognostic factors that influence the outcome of Epstein-Barr virus (EBV)—related posttransplant lymphoproliferative disorder (PTLD) after a rituximab-based treatment in the allogeneic hematopoietic stem cell transplant (HSCT) setting. Methods. A total of 4466 allogeneic HSCTs performed between 1999 and 2011 in 19 European Group for Blood and Marrow Transplantation centers were retrospectively analyzed for PTLD, either biopsy-proven or probable disease. Results. One hundred forty-four cases of PTLD were identified, indicating an overall EBV-related PTLD frequency of 3.22%, ranging from 1.16% for matched-family donor, 2.86% for mismatched family donor, 3.97% in matched unrelated donors, and 11.24% in mismatched unrelated donor recipients. In total, 69.4% patients survived PTLD. Multivariable analysis showed that a poor response of PTLD to rituximab was associated with an age ≥30 years, involvement of extra-lymphoid tissue, acute GVHD, and a lack of reduction of immunosuppression upon PTLD diagnosis. In the prognostic model, the PTLD mortality increased with the increasing number of factors: 0–1, 2, or 3 factors being associated with mortality of 7%, 37%, and 72%, respectively (P < .0001). Immunosuppression tapering was associated with a lower PTLD mortality (16% vs 39%), and a decrease of EBV DNAemia in peripheral blood during therapy was predictive of better survival. Conclusions. More than two-thirds of patients with EBV-related PTLD survived after rituximab-based treatment. Reduction of immunosuppression was associated with improved outcome, whereas older age, extranodal disease, and acute graft-vs-host disease predicted poor outcome.