Hemopoietic stem cell transplantation for infectious mononucleosis-related aplastic anemia.

We report the case of a young woman who developed aplastic anemia (AA), following a serologically confirmed primary Epstein–Barr virus (EBV) infection, occurring with fever and pharyngotonsillitis, in the absence of either palpable lymph nodes or enlarged spleen. Pancytopenia persisted after EBV DNA clearance, requiring multiple red blood cell and platelet transfusions. Given the availability of a human leukocyte antigen (HLA)-matched sibling donor (MSD), hematopoietic stem cell transplantation (HSCT) from bone marrow source was performed after a non-myeloablative conditioning regimen with cyclophosphamide and thymoglobulin. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine A and methotrexate. EBV reactivation occurred, one month post-HSCT, peaking at 28,838 DNA copies/ml in peripheral blood, without evidence of post-transplant lymphoproliferative disorder. Two pre-emptive doses of rituximab were administered, resulting in sustained EBV DNA negativity. Subsequent bone marrow evaluation showed normal cellularity and restoration of peripheral counts. After two years of follow-up, the patient remains transfusion-independent, with stable hematologic recovery, no signs of GVHD, and persistent mixed chimerism (70–75% host cells in peripheral blood; about 60% donor CD3 + lymphocytes). To our knowledge, this is the only second reported case of EBV-related AA successfully treated with MSD HSCT. This case underscores the importance of assessing EBV serology in all patients with AA, since EBV infection may be mild or subclinical, and highlights the efficacy of early rituximab administration in high-level EBV DNA reactivation after transplantation.