Real-World Analysis of 3,843 Unrelated Donors (URDs) for 455 Allograft Candidates Reveals Low URD Availability with Marked Racial/ Ethnic Disparities: Implications for Transplant Center & Registry Operations

• Published in: Transplantation and cellular therapy Vol. 30; no. 2; pp. S23 - S24
• Main Authors: Fingrut, Warren Benjamin, Davis, Eric, Archer, Anne, Brown, Samantha, Devlin, Sean M., Nhaissi, Melissa, Rapoport, Candice, Chinapen, Ms. Stephanie, Kelly, Amanda, Wells, Deborah S., Scaradavou, Andromachi, Gyurkocza, Boglarka, Papadopoulos, Esperanza B., Politikos, Ioannis, Shaffer, Brian C., Barker, Juliet
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.02.2024
• ISSN: 2666-6367; 2666-6367
• DOI: 10.1016/j.jtct.2023.12.065

Despite global URD registry size, the degree to which URD availability is a transplant barrier is unknown. We evaluated URD availability 1/2020-12/2022 in 455 consecutive adult patient (pts) with acute leukemia, MDS or MPN who had a formal search & for whom at least one 5-8/8 URD was requested for confirmatory typing (CT). We hypothesized URD availability is a barrier for underserved racial/ ethnic pts & is not improving. Of 455 pts, 74% (335/455) had European (EURO) & 26% (120/455) non-European (non-EURO) ancestry. For the 455 pts, 3,843 URDs were requested for CT: 71% (2,730/3,843) for EURO [1,411/2,730 (52%) domestic] & 29% (1,113/3,843) for non-EURO [729/1,113 (65%) domestic] pts. Among 2,775 URDs with available donor readiness scores, more URDs requested for non-EURO pts had scores < 30%: 168/702 (24%) vs EURO pts: 32/2,073 (2%), p < .001. 303/455 (67%) pts were transplanted: 266 5-8/8 URD, 20 Cord Blood (CB), 17 haplo. Figs 1A-C & 2A-C show URD availability. • URD CTs/ pt: more non-EURO pts (vs EURO pts) had > 10 URDs requested (p = .045), < 5 URDs available for CT (p < .001), & ≥ 5 URDs unavailable (p < .001). • URD workups/ pt: for over one-quarter of pts (134/455, 29%), 3-5 URDs were requested. More non-EURO pts (vs EURO pts) had < 2 URDs available for workup (p = .007) & ≥ 2 URDs unavailable (p = .017). • URD availability for CT & workup: only half (2,039/3,843, 53%) were available for CT with < 70% (604/889, 68%) available for workup. URDs requested for non-EURO pts were less likely to undergo CT or workup (each p < .001). African & non-Black Hispanic pts had markedly worse URD availability. For African pts, only one-third (150/458, 33%) were available for CT with less than half (32/77, 42%) available for workup; less than half (120/258, 47%) requested for non-Black Hispanic pts underwent CT with less than two-thirds (37/61, 61%) available for workup. • URD availability over time: This did not improve for non-EURO pts post-pandemic (2022). • URD provision: Of 339 pts with ≥ 1 URD who underwent workup, 12% had no URDs available within 14 days of the 1st proposed collection date. Of 263 5-8/8 URD recipients, over one-third (39%) were not transplanted with the primary URD selected. The significant limitations of & ongoing disparities in URD availability have major implications for transplant center & registry operations. Centers should pursue, & registries should permit, simultaneous pursuit of multiple URDs, especially for non-EURO pts (likely many for African & non-Black Hispanic pts). At the outset, the minimum acceptable HLA-match must be decided if few or no 8/8 URDs are likely & if haplo &/or CB grafts will be considered. Centers are obliged to inform pts of poor URD searches/ availability & not pursue futile searches. Finally, while registries should address high URD attrition & speed donor procurement, use of all alternative donors is needed to facilitate transplantation for all.