A retrospective analysis on anti-CD20 antibody-treated Epstein-Barr virus-related posttransplantation lymphoproliferative disorder following ATG-based haploidentical T-replete hematopoietic stem cell transplantation.

Posttransplantation lymphoproliferation disorder (PTLD) is a life-threatening complication after hematopoietic stem cell transplantation (HSCT). Anti-CD20 antibody is the most widely used antibody to eliminate infected B cells. Few studies have focused on prognostic factors predicting the outcome of EBV (Epstein-Barr virus)-PTLD. We conducted a retrospective analysis of 2571 haplo-HSCTs performed between 2010 and 2017 at the Peking University Institute of Hematology; seventy patients who had been treated with rituximab for PTLD were enrolled. The overall EBV-related PTLD frequency was 3.1%. With a median follow-up time of 365 days (range, 54-2659), the overall survival rate was 51.43% (36/70). The cumulative incidence of EBV-PTLD complete remission with anti-CD20 antibody monotherapy was 68.57% (48/70). EBV-PTLD-related mortality was 11.43% (8/70), while the transplantation-related mortality was 38.57% (27/70). Multivariate analysis showed that a decrease in EBV viral load 1 week after therapy was associated with high response rate of EBV-PTLD (p = 0.007, 0.106 (0.021-0.549)), low PTLD-related mortality (p = 0.010, HR 0.058 (0.007-0.503)), and transplantation-related mortality (p = 0.051, HR 0.441 (0.194-1.003)). For EBV-PTLD patients after haplo-HSCT who received rituximab as first-line therapy, non-decreased EBV viral load 1 week after anti-CD20 therapy could be high risk factor for poor outcomes.