Allogeneic hematopoietic stem cell transplantation for infants with idiopathic myelofibrosis.

IMF is a rare disease in children that can present during infancy and has a protracted course. The only known curative approach for this disease in adult patients is allogeneic HSCT. There are very few reports describing the long-term outcome of young children following stem cell transplantation for IMF. We report on eight patients less than two yr of age with IMF that did not resolve with supportive care measures. All patients underwent myeloablative conditioning regimen with busulfan and cyclophosphamide ± ATG followed by HSCT from matched related (n = 6) or unrelated donor (n = 2). All patients achieved neutrophil and platelet engraftment. Four patients had grade II-III acute GVHD, and chronic GVHD developed in five patients (three mild and two severe). At a median follow-up of eight and a half yr (0.7-9), all patients are alive with complete resolution of their hematologic manifestations. At the last follow-up, all patients had normal endocrine function except for one patient who developed hypothyroidism. To date, this is the largest cohort of young children with IMF treated successfully with HSCT, with the longest duration of follow-up. In conclusion, our study showed that HSCT is a curative option for infants with IMF.