Ability of Minority Patients to Find Donors from an Ethnically Diverse Cord Blood Bank
Year of Publication
Baxter-Lowe, LA; Kim, Y; Carter, S; Fernandez-Vina, MA; Wagner, E.; Jensen, L; Fraser, J; Kernan, N; Kurtzberg, J
Annual Meeting of the American Society for Histocompatibility and Immunogenetics
The Cord Blood Transplantation (COBLT) study is investigating the use of unrelated umbilical cord blood (UUCB) for hematopoietic stem cell transplantation. The ethnicity of the 8,038 units currently in the COBLT bank is 42% Caucasian (C), 22% Hispanic (H), 15% African American (AA), 9% Asian (A), and 12% other (O). In 335 active searches (59% non-Caucasian), 94% of patients had a unit matched for at least 4/6 HLA types using intermediate- resolution A and B and high-resolution DRB1 types (original typing). In this interim report of the first 207 patients transplanted with units from the COBLT bank, 36% of patients and 39% of donors were non-Caucasian. For the 133 C, 16 AA, and 6 A patients, the majority of the UUCBs were the same ethnicity (77%, 75%, and 100%, respectively). In contrast, for 34 H patients, only 35% of the units were from H donors. To date, 188 (91%) of the pairs have been retrospectively typed at a high-resolution level (final typing). Using high-resolution types, 6% of patients received a 6/6 HLA matched UUCB Comparison of the original typing with the final typing shows that 65% of 4/6 matches, 61% of 5/6 matches and 69% of 6/6 matches were unchanged. The frequencies of mismatched pairs were 25% 5/6, 47% 4/6, 18% 3/6, and 4% 2/6. For ethnic groups, increased HLA disparity after final typing was highest for H (70%) and A (67%) patients, followed by AA (42%) and C (25%). These data illustrate the current usage of an ethnically diverse cord blood bank. Upon completion of the study, clinical outcomes will be analyzed to investigate the suitability of UUCB transplantation for an ethnically diverse patient population.