Prior immunosuppressive therapy with antithymocyte globulin increases the risk of EBV-related lymphoproliferative disorder following allo-SCT for acquired aplastic anaemia.

We reviewed the incidence and risk factors for EBV-related post-transplant lymphoproliferative disorder (EBV-PTLD) in 89 patients with acquired aplastic anaemia (AAA) receiving allogeneic transplants between 1989 and 2006. The overall incidence of EBV-PTLD was 6.3% (5/89) with no cases in those receiving an allograft for constitutional BM failure syndromes (n=30) during the same period. There was no impact of age, gender, donor status, CMV seropositivity, GVHD and graft cell dose on the occurrence of PTLD. Although both reduced intensity conditioning (RIC) and the prior use of antithymocyte globulin (ATG), as immunosuppressive therapy (IST), were identified as the risk factors for PTLD, only prior use of ATG strongly influenced the development of PTLD with an incidence of 13.38+/-5.6% (5/43), compared with none in those not exposed to ATG before transplantation (P=0.01) with a relative risk of 10.39 for each course of prior ATG. This is the first study in patients with AAA documenting that those receiving multiple prior courses of ATG are at the highest risk of developing EBV-PTLD.