Rituximab treatment for Epstein-Barr virus DNAemia after alternative-donor hematopoietic stem cell transplantation.

We report 55 patients undergoing an alternative-donor hematopoietic stem cell transplantation (HSCT) who developed Epstein-Barr virus (EBV) DNAemia, with >1000 EBV copies/10(5) peripheral blood mononuclear cells (PBMCs), and were treated with rituximab (375 mg/m(2)). The median patient age was 47 years (range, 20-65 years), and graft sources were mismatched family members (n = 4), unrelated donors (n = 46), and unrelated cord blood (n = 5). The conditioning regimen included antithymocyte globulin (ATG) in all patients. The median time to development of EBV DNAemia was day 27 post-HSCT (range, day 5 to day 242), with a median of 60 EBV copies/10(5) PBMCs (range, 1-5770 copies/10(5) PBMCs). The number of EBV copies was reduced to <1000/10(5) PBMCs on day +7 after initiation of rituximab therapy in 51% of the patients, on day +14 in 73% of the patients, and on +21 in 92% of the patients. Overall, 50 of 55 patients (91%) cleared EBV after one dose (n = 25) or more than one dose (n = 25) of rituximab. Factors predicting transplantation-related mortality (TRM) in multivariate analysis were a reduction to <1000 EBV copies/10(5) PBMCs by day +7 of treatment (relative risk [RR], 0.2; P = .01) and disease phase in remission (RR, 0.3; P = .05). TRM was 23% in the 40 patients with none or one of the negative predictors and 60% in the 15 patients with both negative predictors (P = .001). Of these latter 15 patients, 3 developed clinical posttransplantation lymphoproliferative disorder (PTLD). All 3 of these patients had a high EBV load on day +7 of rituximab therapy. This study confirms the effectiveness of rituximab in controlling EBV DNAemia in patients undergoing allogeneic HSCT. Patients with increasing EBV copies despite rituximab therapy are at high risk for EBV PTLD and may be considered for alternative therapies.

Transplant-related mortality and long-term graft function are significantly influenced by cell dose in patients undergoing allogeneic marrow transplantation.

We have studied the impact of cell dose on short- and long-term graft function and outcome in 905 patients undergoing an unmanipulated allogeneic bone marrow transplantation (BMT) from an HLA-identical sibling (n = 735), a one-antigen mismatched related donor (n = 35), or a matched unrelated donor (n = 135). Median number of nucleated cells infused was 3.4 x 10(8)/kg (25th percentile 2.4 x 10(8)/kg, 75th percentile 5 x 10(8)/kg). Patients were stratified according to cells infused in 3 groups: < or = 2.4 x 10(8)/kg (n = 247; low dose); >2.4 x 10(8)/kg and < or = 5 x 10(8)/kg (n = 452; intermediate dose); and >5 x 10(8)/kg (n = 206; high dose). Patients receiving high cell dose had significantly higher platelet counts on days +20, +50, +100, +180, and +365 after BMT (P <.01) and higher white blood cell counts on days +50, +100, and +180 after BMT (P <.01) as compared with other patients. The actuarial 5-year transplant-related mortality (TRM) was 41% versus 36% versus 28% (P =.01); overall survival was 45% versus 51% versus 56% (P =.0008); and disease-free survival was 41% versus 42% versus 48%, respectively, (P =.04) in patients receiving low, intermediate, or high cell dose. The cell dose effect was more pronounced in patients older than 30 years of age, with advanced disease, with chronic myeloid leukemia, and with alternative donors. In multivariate Cox analysis on TRM, cell dose was a significant predictor (P =.002; relative risk 0.6) together with donor type (P =.0001), year of transplantation (P =.0001), conditioning regimen (P =.02), and recipient age (P =.02). In conclusion, transplantation of high marrow cell dose is associated with reduced transplant mortality and improved survival and results in improved graft function both short and long term.