[Successful treatment of rapidly progressive Epstein-Barr virus-associated lymphoproliferative disorder with upfront allogeneic hematopoietic cell transplantation].

A 54-year-old woman presented with a chief concern of right back pain that had persisted for 3 weeks. Laboratory tests revealed pancytopenia, liver dysfunction, and coagulation abnormalities. She had hepatomegaly and splenomegaly but no lymphadenopathy. No abnormal cells were detected in the bone marrow or on a liver biopsy. Epstein-Barr virus (EBV) DNA levels in the peripheral blood were high at 6.44 log IU/ml, and clonality of EBV-infected cells was confirmed by Southern blot hybridization with a probe targeting the EBV terminal repeat. EBV-infected NK cells were detected using the magnetic bead method. This led to a diagnosis of EBV-associated lymphoproliferative disease (EBV-LPD). As pancytopenia and coagulation abnormalities induced by the development of hemophagocytic syndrome continued to worsen after steroid therapy, we performed intensive chemotherapy followed by umbilical cord blood transplantation. After transplantation, EBV-DNA levels in the peripheral blood were undetectable, with complete donor chimerism. In the present case, the rapid disease progression with an extremely high EBV-DNA level indicated a poor prognosis. Intensive chemotherapy followed by upfront allogeneic hematopoietic cell transplantation may be necessary in patients with rapidly progressing EBV-LPD.