Epstein-Barr virus (EBV) reactivation is a frequent event after allogeneicstem cell transplantation (SCT) and quantitatively predicts EBV-lymphoproliferative disease following T-cell-depleted SCT

Reactivation of the Epstein-Barr virus (EBV) after allogeneic stem cell tra nsplantation (allo-SCT) may evoke a protective cellular immune response or may be complicated by the development of EBV-lymphoproliferative disease (E BV-LPD). So far, very little is known about the incidence, recurrence, and sequelae of EBV reactivation following allo-SCT. EBV reactivation was retro spectively monitored in 85 EBV-seropositive recipients of a T-cell-depleted (TCD) allo-SCT and 65 EBV-seropositive recipients of an unmanipulated allo -SCT. Viral reactivation (more than So EBV genome equivalents [gEq]/mL) was monitored frequently by quantitative realtime plasma polymerase chain reac tion until day 180 after SCT. Probabilities of developing viral reactivatio n were high after both unmanipulated and TCD-allogeneic SCT (31% +/- 6% ver sus 65% +/- 7%, respectively). A high CD34(+) cell number of the graft appe ared as a novel significant predictor (P = .001) for EBV reactivation. Recu rrent reactivation was observed more frequently in recipients of a TCD graf t, and EBV-LPD occurred only after TCD-SCT. High-risk status, TCD, and use of antithymocyte globulin were predictive for developing EBV-LPD. Plasma EB V DNA quantitatively predicted EBV-LPD. The positive and negative predictiv e values of a viral load of 1000 gEq/mL were, respectively, 39% and 100% af ter TCD. Treatment-related mortality did not differ significantly between T CD and non-TCD transplants, but the incidence of chronic graft-versus-host disease was significantly less in TCD patients. It is concluded that EBV re activation occurs frequently after TCD and unmanipulated allo-SCT, especial ly in recipients of grafts with high CD34(+) cell counts. EBV-LPD, however, occurred only after TCD, and EBV load quantitatively predicted EBV-LPD in recipients of a TCD graft. (C) 2001 by The American Society of Hematology.