Hematopoietic engraftment and survival in adult recipients of umbilical-cord blood from unrelated donors.

Background: Umbilical-cord blood from unrelated donors who are not HLA-iden tical with the recipients can restore hematopoiesis after myeloablative the rapy in children. We studied the use of transplantation of umbilical-cord b lood to restore hematopoiesis in adults. Methods: Sixty-eight adults with life-threatening hematologic disorders rec eived intensive chemotherapy or total-body irradiation and then transplants of HLA-mismatched umbilical-cord blood. We evaluated the outcomes in terms of hematologic reconstitution, the occurrence of acute and chronic graft-v ersus-host disease (GVHD), relapses, and event-free survival. Results: Of the 68 patients, 48 (71 percent) received grafts of umbilical-c ord blood that were mismatched for two or more HLA antigens. Of the 60 pati ents who survived 28 days or more after transplantation, 55 had neutrophil engraftment at a median of 27 days (range, 13 to 59). The estimated probabi lity of neutrophil recovery in the 68 patients was 0.90 (95 percent confide nce interval, 0.85 to 1.0). The presence of a relatively high number of nuc leated cells in the umbilical-cord blood before it was frozen was associate d with faster recovery of neutrophils. Severe acute GVHD (of grade III or I V) occurred in 11 of 55 patients who could be evaluated within the first 10 0 days after transplantation. Chronic GVHD developed in 12 of 33 patients w ho survived for more than 100 days after transplantation. The median follow -up for survivors was 22 months (range, 11 to 51). Of the 68 patients, 19 w ere alive and 18 of these (26 percent) were disease-free 40 months after tr ansplantation. The presence of a high number of CD34+ cells in the graft wa s associated with improved event-free survival (P = 0.05). Conclusions: Umbilical-cord blood from unrelated donors can restore hematop oiesis in adults who receive myeloablative therapy and is associated with a cceptable rates of severe acute and chronic GVHD. (N Engl J Med 2001;344:18 15-22.) Copyright (C) 2001 Massachusetts Medical Society.