Hemophagocytic lymphohistiocytosis (HLH) is a rare disease of infancy and young childhood. The clinical presentation includes recurrent unexplained fever with hepatosplenomegaly. Cytopenia, hypofibrinogenemia and/or hypertriglyceridemia and hemophagocytosis in bone marrow, spleen and lymphnode confirm the diagnosis. Hemophagocytosis may not be present at the beginning. In these cases, diagnosis is facilitated by a positive family history, a relapsing course of the disease, the frequent involvement of the central nervous system and positive findings on immunological work-up. Treatment by chemotherapy and immunosuppressants can achieve sustained remissions in most patients and reinduction of remission after relapse is possible. Most children however, eventually die from progressive disease. At present, allogeneic bone marrow transplantation is the only curative therapeutic option. Between August 1992 and May 1997 eleven consecutive patients with HLH received bone marrow from unrelated (n = 7) or matched sibling donors (n = 4). The conditioning regimen consisted of busulfan, VP-16 and cyclophosphamide. Patients engrafted after a median time of 16 days (13-43). Only one patient developed grade III acute GVHD, another patient, grade II acute GVHD. Although regimen-related toxicity was extensive, all patients have survived without signs of HLH after a median follow up of 20 months (8-63). One patient suffers from chronic GVHD, three patients reveal psychomotoric retardation and one patient has severe impairment with spastic tetraparesis, amaurosis and seizures. Our experience shows that HLH can be successfully treated by allogeneic BMT from unrelated donors.
