Excellent outcome of allogeneic hematopoietic SCT with reduced-intensity conditioning for the treatment of chronic active EBV infection.

Since we reported the first successful case of allogeneic hematopoietic SCT (allo-HSCT), we have performed allo-HSCT for 29 patients with chronic active EBV infection (CAEBV), using either myeloablative conditioning (MAC) allo-HSCT (MAST) or reduced-intensity conditioning (RIC) allo-HSCT (RIST). In this retrospective analysis we compared the outcomes after MAST and RIST to identify the optimal conditioning for patients with CAEBV. Of 29 patients, 11 underwent allo-HSCT with MAC, consisting of TBI (12 Gy), etoposide (900 mg/m²) and CY (120 mg/kg) or melphalan (210 mg/m²), and the remaining 18 patients received allo-HSCT after RIC, consisting of fludarabine (∼ 180 mg/m²) and melphalan (140 mg/m²) or CY (120 mg/kg), with/without antithymocyte globulin and low-dose irradiation. Donor sources were 8 related BM, 2 related peripheral blood, 5 CD34 selected cells from HLA-haploidentical donors, 8 unrelated BM and 8 unrelated cord blood. The 3-year-EFS rate was 54.5 ± 15.0% for MAST group and 85.0 ± 8.0% for RIST group, and the 3-year OS rate was 54.5 ± 15.0% for MAST group and 95.0 ± 4.9% for RIST group (P = 0.016). Allo-HSCT after RIC seems to be a promising approach for the treatment of CAEBV.