Post-transplant lymphoproliferative disease (PTLD) after haematopoietic stem cell transplantation is a life-threatening complication and the number of patients at risk is increasing over time. In the majority of patients Epstein-Barr virus-related PTLD (EBV-PTLD) is diagnosed with a histological picture of B-cell lymphoma. In 2009 recommendations for diagnosis, monitoring and treatment of patients with EBV-PTLD were published. Definitions of preemptive treatment and therapy of probable or proven PTLD were introduced. Results of preemptive treatment and therapy of documented PTLD are discussed in this paper, with the emphasis on monoclonal antibody anti-CD20 rituximab effectiveness and indications for its applications. A comprehensive review of reported cases of PTLD and summary of results indicate that rituximab in monotherapy or in combination treatment is successful in 63% of confirmed PTLD cases and in 89% when used preemptively. Still, an analysis of factors determining the response to therapy is lacking. Post-transplant lymphoproliferative disease tends to present in the first year after transplant, but may occur late, even many years after the procedure. The majority of early cases are associated with EBV (Epstein-Barr virus) infection and appear as B-cell proliferation. Up to 30% of PTLDs are EBV-negative and usually occur late after transplant. The aetiology of EBV-negative PTLD is unknown; however, an association with HHV8 (human herpes virus 8) has been described. The late form of PTLD and EBV-negative PTLD may appear as T/NK cell proliferation.Epstein-Barr virus is a widespread human herpesvirus and more than 90% of the healthy population is seropositive. EBV leads to transformation and proliferation of infected B lymphocytes, but in healthy individuals this process is controlled by the immune system [3,4]. Involvement of EBV in oncogenesis is proved in many malignancies, especially in lymphoproliferative diseases, both primary and secondary [5,6].
Epidemiology of Epstein-Barr virus-associated post-transplant lymphoproliferative disease after haematopoietic stem cell transplantationPost-transplant lymphoproliferative disease developing after HSCT is usually related to EBV reactivation or, less often, to primary infection. The varying incidence ranging from 0.45% to 29% of reported EBV-PTLD is related to intensity of immunosuppression used and reflects different practice between centres with respect to patient population, conditioning, graft versus host disease (GVHD) prophylaxis, and source of stem cells. Identified risk factors include HSCT from unrelated, mismatched or haploidentical donors, umbilical cord blood transplants, T-depletion (in vivo or in vitro), use of antithymocyte globulin (ATG), and also splenectomy, serological mismatch between donor and recipient and chronic GVHD (Table 1) [7,8]. The risk of PTLD increases with two or more risk factors.Major Minor unrelated/mismatch HSCT primary EBV infection T-cell depletion (in vivo or in vitro) splenectomy EBV serology mismatch chronic GVHD cor...