The Royan Public Umbilical Cord Blood Bank: Does It Cover All Ethnic Groups in Iran Based on HLA Diversity?

Abstract

Background: Umbilical cord blood (UCB) stem cells allow the transplantation of partially human leukocyte antigen (HLA)-matched grafts and are a valuable resource for the treatment of hematologic malignancies and heritable hematologic, immunologic and metabolic diseases, especially when a compatible bone marrow donor is unavailable. The aim of this study was to determine how many ethnic groups in Iran are covered by the available UCB units based on HLA diversity. Methods: From 2009 until mid-2013, 4,981 (30.3%) of the 16,437 UCB samples collected met the storage criteria and were cryopreserved at a public cord blood bank (CBB) in Tehran, Iran. HLA-A, -B and -DRB1 were typed in 1,793 samples. Results: The mean volume of the cryopreserved samples was 81.25 ± 20.3 ml. The range of total nucleated cells per unit was 51 × 10⁷-107 × 10⁷. The most common HLA alleles were HLA-A*2 (17%) and HLA-A*24 (15.6%), HLA-B*35 (16.8%) and HLA-B*51 (13.9%), and HLA-DRB1*11 (20%) and HLA-DRB1*15 (14%). The predominant haplotypes were HLA-A*24-B*35-DRB1*11 (2%), HLA-A*02-B*50-DR*07 (1.8%), and HLA-A*02-B*51-DRB1*11 (1.5%). Conclusions: Based on the HLA-DRB1 profiles, the UCB units available at the Royan public UCB bank are a potentially adequate resource for hematopoietic stem cell transplantation for Iranian recipients belonging to particular ethnic groups. Regular educational programs to improve the public knowledge of UCB for transplantation can enhance the public CBB stocks for all Iranian ethnic groups in the future.