182: Mobilization of PML-RARA negative peripheral blood stem cells and autologous peripheral blood stem cell transplant in pediatric patients with relapsed acute promyelocytic leukemia
Biology of Blood and Marrow Transplantation
cine and ultrasound has led to the possibility of in utero diagnosis and treatment with intrauterine transfusions. Rare cases of premature infants surviving and undergoing chronic transfusion therapy have been reported. Hematopoietic stem cell transplant (HSCT) has become increasingly used to cure beta thalassemia, and provides the potential to cure ␣ 0 thalassemia. To date, 3 reported cases of ␣ 0 thalassemia have been treated with HSCT. Two children underwent matched sibling HSCT at 20 and 21
... months of age and one a 5/6 HLA matched sibling umbilical cord blood transplant (UCBT). One child had received intrauterine transfusions. We report a case of an infant with ␣ 0 thalassemia successfully treated with intrauterine transfusions followed by unrelated donor UCBT. The mother, of Cambodian descent, noticed decreased fetal movement at 23 weeks gestation and ultrasound revealed hydrops fetalis. Based on nationality and previous fetal loss, the suspicion of ␣ 0 thalassemia was raised. UCB sampling revealed a hypochromic, microcytic anemia with target cells. The Hgb electrophoresis demonstrated Hgb Barts and Portland. Subsequent genotyping confirmed deletion of all 4 ␣-globin genes. The patient received 3 intrauterine transfusions prior to delivery at 32 weeks. The hospital course was relatively uneventful and included PRBC transfusions. After discharge, he received 3 transfusions. Following informed consent, at 6 months of age, he was conditioned for transplant with busulfan, cytoan and ATG. Lacking an HLA matched sibling, he received a 5/6 HLA matched unrelated donor UCB unit delivering 11.8 ϫ 10 7 nucleated cells/kg. Neutrophil engraftment (ANCϾ500) was achieved on day ϩ 15. FK506 and methotrexate 5mg/m2 on days 1, 3 and 6 was utilized for GVHD prophylaxis. His course was complicated by moderate venoocclusive disease, small subdural hemorrhage, and viremia. He has not had any evidence of graft versus host disease. Initial chimerism (STRs) showed approximately 63% donor derived cells, since increasing with 100% T-cell engraftment. He clinically is doing well post transplant. This case demonstrates that intrauterine transfusion followed by unrelated donor UCBT is feasible for the treatment of ␣ 0 thalassemia.