ENGRAFTMENT OF UNRELATED DONOR STEM-CELLS IN CHILDREN WITH FAMILIAL AMEGAKARYOCYTIC THROMBOCYTOPENIA

Congenital amegakaryocytic thrombocytopenia is an extremely rare disor der for which bone marrow transplantation offers the only possibility for cure, The pathophysiology is unclear, Two children with familial a megakaryocytic thrombocytopenia underwent unrelated donor transplantat ion (bone marrow in one, umbilical cord blood in the second) after a p reparative regimen of cyclophosphamide and total body irradiation, Bot h patients failed initial engraftment, required further donor stem cel l infusions and are currently well with sustained engraftment, 16 mont hs and 7 months after transplantation, respectively, The difficulty in achieving engraftment of unrelated donor stem cells in these children suggests that in future cases additional measures to achieve engraftm ent may be necessary, for example, a more aggressive preparative regim en or an increased stem cell dose.