ALLOGENEIC SIBLING UMBILICAL-CORD-BLOOD TRANSPLANTATION IN CHILDREN WITH MALIGNANT AND NONMALIGNANT DISEASE

Allogeneic bone marrow transplantation is limited by the availability of suitable marrow donors and risk of graft-versus-host disease (GVHD) and opportunistic infection. In an attempt to ameliorate these limita tions, umbilical cord blood has been postulated as an alternative sour ce of allogeneic haemopoietic stem cells for transplantation. From Sep tember, 1994, umbilical cord blood from sibling donors has been used t o reconstitute haemapoiesis in 44 children with acquired or congenital lympho-haemapoietic disorders, neuroblastoma, or metabolic diseases. Patients who had HLA-identical and HLA-1 antigen disparate grafts, had a probability of engraftment at 50 days after transplantation of 85%. No patient had late graft failure. The probability of grade II-IV GVH D at 100 days was 3% and the probability of chronic GVHD at one year w as 6%. With a median follow-up of 1.6 years, the probability of surviv al for recipients of HLA-identical or HLA-1 antigen disparate grafts i s 72%. We conclude that umbilical cord blood is a sufficient source of transplantable haemopoietic stem cells for children with HLA-identica l or HLA-1 antigen disparate sibling donors with very low risk of acut e or extensive chronic GVHD. The feasibility of umbilical-cord-blood t ransplantation with HLA-2 and HLA-3 antigen disparate sibling donors r emains to be determined.