Evaluation of Cord Blood Total Nucleated and CD34+ Cell Content, Cell Dose, and 8-Allele HLA Match by Patient Ancestry

• Published in: Biology of blood and marrow transplantation Vol. 26; no. 4; pp. 734 - 744
• Main Authors: Barker, Juliet N., Mazis, Christopher M., Devlin, Sean M., Davis, Eric, Maloy, Molly A., Naputo, Kristine, Nhaissi, Melissa, Wells, Deborah, Scaradavou, Andromachi, Politikos, Ioannis
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.04.2020
• Subjects: Ancestry; CD34+ cell content; Cord blood; HLA match; TNC content; Ancestry; TNC content; Cord blood; HLA match; CD34+ cell content; CD34(+) cell content
• ISSN: 1083-8791; 1523-6536
• DOI: 10.1016/j.bbmt.2019.11.017

•Racial disparities exist in unrelated donor cord blood (CB) cell content, dose, and HLA matching.•Nearly all European and most non-European adult patients have suitable double-unit CB grafts.•Many Europeans have high-dosed, well-matched CB units.•Acceptance of a high degree of HLA mismatch is needed to permit CB transplantation in many non-Europeans.•Patients without suitable CB units are predominantly non-European with high weight. How cord blood (CB) CD34+ cell content and dose and 8-allele HLA match vary by patient ancestry is unknown. We analyzed cell content, dose, and high-resolution HLA-match of units selected for CB transplantation (CBT) by recipient ancestry. Of 544 units (286 infused, 258 next-best backups) chosen for 144 racially diverse adult patients (median weight, 81 kg), the median total nucleated cell (TNC) and CD34+cell +contents were higher for Europeans than for non-Europeans: 216 × 107versus 197 × 107 (P = .002) and 160 × 105 versus 132 × 105 (P = .007), respectively. There were marked cell content disparities among ancestry groups, with units selected for Africans having the lowest TNC (189 × 107) and CD34+ cell (122 × 105) contents. Units for non-Europeans were also more HLA-mismatched (P = .017). When only the 286 transplanted units were analyzed, the adverse effect of reduced cell content was exacerbated by the higher weights in some groups. For example, northwestern Europeans (high patient weight, high unit cell content) had the best-dosed units, and Africans (high weight, low unit cell content) had the lowest. In Asians, low cell content was partially compensated for by lower weight. Marked differences in 8-allele HLA-match distribution were also observed by ancestry group; for example, 23% of units for northwestern Europeans were 3/8 to 4/8 HLA-matched, compared with 40% for southern Europeans, 46% for white Hispanics, and 51% for Africans. During the study period, 20 additional patients (17 non-Europeans; median weight, 98 kg) did not undergo CBT owing to the lack of a suitable graft. CB extends transplantation access to most patients, but racial disparities exist in cell content, dose, and HLA match.