Successful mismatched sibling cord blood transplant in Hb Bart's disease.

A 20-month-old girl with Hb Bart's disease, who had survived neonatal complications, underwent HLA-DR antigen mismatched sibling cord blood transplantation successfully. Immune thrombocytopenia, which occurred around 2.5 months after transplant, responded to intravenous gamma-globulin. The fetal hemoglobin level rose to a peak of 52.3% on day +69 post transplant and declined gradually during the following year. Ten percent of hemoglobin Bart's was detected 2 months after transplant and this reflects the alpha-thalassemia trait of the donor.