A case of hemophagocytic lymphohistiocytosis with prolonged remission after syngeneic bone marrow transplantation

We report a 7-year-old girl with hemophagocytic lymphohistiocystosis who re ceived a syngeneic bone marrow transplant from her twin sister. She present ed with high fever and cough. Laboratory findings revealed pancytopenia, el evation of liver enzymes, and hyperferritinemia, Bone marrow examination re vealed histiocytic hemophagocytes and lymphoblastoid cells. Southern blot a nalysis of the bone marrow cells revealed a monoclonal proliferation of EBV -infected lymphocytes, Although she underwent combined chemotherapy accordi ng to the HLH-94 protocol, she developed severe pancytopenia. Following mye loablative conditioning with busulfan (16 mg/kg), cyclophosphamide (120 mg/ kg), and etoposide (1.5 g/m(2)), she was transplanted with 6.6 x 10(8)/kg m ononuclear cells from the twin sister. She remains in complete remission 23 months after transplantation.