Search for unrelated donor umbilical cord blood units for allogeneic stem cell transplantation: results in two time periods.
Umbilical cord blood (UCB) banks have increased their stock worldwide in the past years. There are more than 230,000 available units today. The ideal UCB graft is a unit that is matched in five or six of six HLA. A, B (low-resolution) and DRB1 (high-resolution) alleles and which has over 2.5 x 107 nucleated cells/kg body weight (BW). Four of six matched units are also used specially if the cell dose gives more than 3 x 10(7) nucleated cells/kg BW. Our unrelated donor UCB transplant program was started in 1996 searching international cord blood banks (Netcord, New York) for patients with a definitive or potential indication for stem cell transplantation who lacked a matched family donor.


METHODS
From 1995 to 1996, a search was initiated for 87 patients with malignant (n = 56, 37 acute leukemia) and nonmalignant conditions (16 congenital diseases, 14 aplastic anemia). Patient data along with low-resolution A, B, and DR typing were sent to the New York Blood Center, along with a blood sample for high-resolution DRB1 typing. Parallel searches were done in the Netcord database among UCB units with reported high-resolution DRB1 typing. Forty-eight searches were done between 1995 and 2000 (31 with high resolution) and 39 were done between 2000 and 2005 (33 with high resolution). UCB units were considered adequate if they had more than 2.7 x 10(7) cells/kg BW.


RESULTS
During the first period, four patients (13%) matched five of six high-resolution unit and 21 (67%) a four of six match. During the second period, 15 patients (46%) found a five of six match and 16 (48%) a four of six match (P = .012).


CONCLUSIONS
Nearly half of our patients find an optimal matched UCB unit for transplantation in international banks. The creation of a local UCB bank in our country is supported by these data.
Barriga
F
F
Department of Pediatrics, Catholic University of Chile, Santiago, Chile.
Wietstruck
M A
MA
D000741:Anemia, Aplastic / Q000628:therapy; D036101:Cord Blood Stem Cell Transplantation / Q000706:statistics & numerical data*; D005312:Fetal Blood; D006684:HLA-DR Antigens / Q000276:immunology; D006650:Histocompatibility Testing / Q000706:statistics & numerical data; D006801:Humans; D007231:Infant, Newborn; D009369:Neoplasms / Q000628:therapy; D014019:Tissue Donors; D014184:Transplantation, Homologous
D006684:HLA-DR Antigens