Epstein-Barr virus related post-transplant lymphoproliferative disorder prevention strategies in allogeneic hematopoietic stem cell transplantation

Epstein-Barr virus associated post-transplant lymphoproliferative disorders (EBV PTLD) are recognized as a significant cause of morbidity and mortality in patients undergoing allogeneic hematopoietic stem cell transplantation (alloHSCT). The number of patients at risk of developing EBV PTLD is increasing, partly as a result of highly immunosuppressive regimens, including the use of anti-thymocyte globulin (ATG). Importantly, there is heterogeneity in PTLD management strategies between alloHSCT centers worldwide. This review summarizes the different EBV PTLD prevention strategies being utilized including the alloHSCT and T-cell depletion regimes and the risk they confer; monitoring programs, including the timing and analytes used for EBV virus detection, as well as pre-emptive thresholds and therapy with rituximab. In the absence of an institution-specific policy, it is suggested that the optimal pre-emptive strategy in HSCT recipients with T-cell depleting treatments, acute graft vs host disease (GVHD) and a mismatched donor for PTLD prevention is (a) monitoring of EBV DNA post-transplant weekly using plasma or WB as analyte and (b) pre-emptively reducing immune suppression (if possible) at an EBV DNA threshold of >1000 copies/mL (plasma or WB), and treating with rituximab at a threshold of >1000 copies/mL (plasma) or >5000 copies/mL (WB). There is emerging evidence for prophylactic rituximab as a feasible and safe strategy for PTLD, particularly if pre-emptive monitoring is problematic. Future management strategies such as prophylactic EBV specific CTLs have shown promising results and as this procedure becomes less expensive and more accessible, it may become the strategy of choice for EBV PTLD prevention.