SUCCESSFUL TRANSPLANTATION OF HLA-MATCHED AND HLA-MISMATCHED UMBILICAL-CORD BLOOD FROM UNRELATED DONORS - ANALYSIS OF ENGRAFTMENT AND ACUTEGRAFT-VERSUS-HOST DISEASE

To reduce the morbidity and mortality associated with unrelated donor bone marrow (BM) transplantation and potentially extend the pool of su itable donors, cryopreserved unrelated donor umbilical cord blood was considered as an alternate source of hematopoietic stem cells for tran splantation. Patients with leukemia, BM failure syndrome, or inborn er ror of metabolism were eligible for a phase I clinical trial designed to estimate the risk of graft failure and severe acute graft-versus-ho st disease after transplantation of umbilical cord blood from unrelate d donors. As of December 21, 1995, unrelated donor umbilical cord bloo d was used to reconstitute hematopoiesis in eighteen patients aged 0.1 to 21.3 years weighing 3.3 to 78.8 kg with acquired or congenital lym pho-hematopoietic disorders or metabolic disease. Patients received ei ther HLA-matched (n = 7) or HLA-1 to 3 antigen disparate (n = 11) graf ts collected and evaluated by the New York Blood Center (New York, NY) , The probability of engraftment after unrelated donor umbilical cord blood transplantation was 100% with no patient having late graft failu re to date. The probability of grade III-IV acute graft-versus-host di sease at 100 days was 11%. With a median follow-up of 6 months (range, 1.6 to 17 months), the probability of survival at 6 months is 65% in this high risk patient population, We conclude that cryopreserved umbi lical cord blood from HLA-matched and mismatched unrelated donors is a sufficient source of transplantable hematopoietic stem cells with hig h probability of donor derived engraftment and low risk of refractory severe acute graft-versus-host disease, Limitations with regard to rec ipient size and degree of donor HLA disparity remain to be determined. (C) 1996 by The American Society of Hematology.