Analysis of engraftment, graft-versus-host disease, and immune recovery following unrelated donor cord blood transplantation

Unrelated cord blood (UCB) is being used as a source of alternative hematop oietic stem cells for transplantation with increasing frequency From Novemb er 1994 to February 1999, 30 UCB transplant procedures were performed for b oth malignant and nonmalignant diseases in 27 children, aged 0.4 to 17.1 ye ars. Patients received either HLA-matched (n = 3) or 1- or 2-antigen-mismat ched (n = 27) UCB following 1 of 2 standardized preparative and graft-versu s-host disease regimens (hyperfractionated total body irradiation, cyclopho sphamide, and antithymocyte globulin [ATG] with cyclosporine A and methotre xate; or busulfan, melphalan, and ATG with cyclosporine A and prednisone). The median time to neutrophil and platelet engraftment was 27 days (12-60 d ays) and 75 days (33-158 days) posttransplantation, respectively. No correl ation was noted between neutrophil and platelet engraftment and nucleated c ells per kilogram, CD34(+) cells per kilogram infused, or cytomegalovirus s tatus of recipient. The cumulative probability of acute grade 2 or greater graft-versus-host disease (GVHD) was 37.2%, and of grade 3 or greater GVHD was 8.8%. No patients developed chronic GVHD, CD4, CD19, and natural killer cell recovery was achieved at a median of 12, 6, and 2 months, respectivel y. CD8 recovery was delayed at a median of 9 months. Normal mitogen respons e was achieved at 6 to 9 months. The probability of survival, disease-free survival, and event-free survival at 1 year was 52.3% (34.1%-70.5%), 54.7% (34.5%-74.9%) and 49.6% (29.9%-69.4%), respectively. This series of 30 UCB transplants suggests that although CD8 cell recovery is delayed, the patter n of immune reconstitution with UCB is similar to that reported for other s tem cell sources.(Blood. 2000;96:2703-2711) (C) 2000 by The American Societ y of Hematology.