[Lymphoproliferative disorder as a complication after haematopoietic stem cell transplantation]

Lymphoproliferative disorders (LPD) occur often in EBV-infected patients, especially in solid-organ and haematopoietic stem cell transplant recipients. The risk of developing LPD ranges from 1 to 25% and depends on the type of transplantation. We are presenting the case of a 9-year-old boy with acute myelogenous leukaemia in second remission, who developed LPD after matched unrelated donor bone marrow transplantation (MUD BMT) not identical in two loci. On day 50 after BMT the patient presented with fever and symptoms of paronychia. Two weeks later, bilateral cervical tenderness and adenopathy and hepatosplenomegaly developed. Bone marrow biopsy confirmed continuing remission. An extensive infection workup, including bacterial, mycotic and CMV infection yielded negative results. Basing on clinical picture and suspecting LPD, EBV-PCR was performed. The patient was found to have extremely high EBV DNA levels (4.905.152 genomes/mcg) in the peripheral blood. On days 64 and 73 after BMT, the patient received two doses of rituximab (MabThera) (375 mg/m(2)) After the first dose of rituximab EBV DNA copy numbers decreased to 707.723/mcg. However the patient's general condition was worsening; 71 days after BMT increasing aplasia and symptoms of venoocclusive disease (VOD) developed. The patient received two doses of defibrotide (Novarid). Despite of intensive therapy, progressive hepatic failure and increasing pulmonary oedema led to the patient's death, on day 96 after BMT.