Epstein–Barr virus reactivation in allogeneic stem cell transplantation is highly related to cytomegalovirus reactivation

Monitoring of Epstein–Barr virus (EBV) load and pre‐emptive rituximab is an appropriate approach to prevent post‐transplant lymphoproliferative disease (PTLD) occurring after hematopoietic stem cell transplantation (HSCT). This pre‐emptive approach, based on EBV‐DNA monitoring through a quantitative polymerase chain reaction, was applied to 101 consecutive patients who underwent allo HSCT at our Institute (median age 50). A single infusion of rituximab was administered to 11 of 16 patients who were at high risk for progression to PTLD, defined as a DNA value >10 000 copies/mL. All patients cleared EBV DNAemia, without any recurrences. Main factors significantly associated with high risk for PTLD were as follows: (i) unrelated vs. sibling (26% vs. 7%; p = 0.011); (ii) T‐cell depletion (29% vs. 6%; p = 0.001); (iii) graft versus host disease (GVHD; 30% vs. 7%; p = 0.002); and (iv) cytomegalovirus (CMV) reactivation (29% vs. 4%; p = 0.001). Multivariate analysis showed that CMV reactivation was the only independent variable associated with EBV reactivation. We conclude that: (i) a single infusion of rituximab is able to prevent the risk of progression into EBV‐related PTLD; and (ii) CMV reactivation is strongly associated with EBV reactivation; therefore, an intensive EBV monitoring strategy could be advisable only in case of CMV reactivation.