Abstract

We evaluated 18,014 patients who underwent allogeneic bone marrow transplantation (BMT) at 235 centers worldwide to examine the incidence of and risk factors for posttransplant lymphoproliferative disorders (PTLD). PTLD developed in 78 recipients, with 64 cases occurring less than 1 year after transplantation. The cumulative incidence of PTLD was 1.0% +/- 0.3% at 10 years. Incidence was highest 1 to 5 months posttransplant (120 cases/10,000 patients/yr) followed by a steep decline to less than 5/10,000/yr among >/=1-year survivors. In multivariate analyses, risk of early-onset PTLD (<1 year) was strongly associated (P <.0001) with unrelated or human leukocyte antigen (HLA) mismatched related donor (relative risk [RR] = 4.1), T-cell depletion of donor marrow (RR = 12.7), and use of antithymocyte globulin (RR = 6.4) or anti-CD3 monoclonal antibody (RR = 43.2) for prophylaxis or treatment of acute graft-versus-host disease (GVHD). There was a weaker association with the occurrence of acute GVHD grades II to IV (RR = 1.9, P =.02) and with conditioning regimens that included radiation (RR = 2.9, P =.02). Methods of T-cell depletion that selectively targeted T cells or T plus natural killer (NK) cells were associated with markedly higher risks of PTLD than methods that removed both T and B cells, such as the CAMPATH-1 monoclonal antibody or elutriation (P =.009). The only risk factor identified for late-onset PTLD was extensive chronic GVHD (RR = 4.0, P =.01). Rates of PTLD among patients with 2 or >/=3 major risk factors were 8.0% +/- 2.9% and 22% +/- 17.9%, respectively. We conclude that factors associated with altered immunity and T-cell regulatory mechanisms are predictors of both early- and late-onset PTLD.