-Author name in bold denotes the presenting author
-Asterisk * with author name denotes a Non-ASH member
Clinically Relevant Abstract denotes an abstract that is clinically relevant.

PhD Trainee denotes that this is a recommended PHD Trainee Session.

Ticketed Session denotes that this is a ticketed session.

3342 Evaluation of Cord Blood (CB) Unit TNC & CD34+ Cell Content & Donor-Recipient High-Resolution 8 HLA-Allele Match By Patient Ancestry: An Evaluation of 513 CB Units in a Racially & Ethnically Diverse Population of Adults with Hematologic Malignancies

Program: Oral and Poster Abstracts
Session: 711. Cell Collection and Processing: Poster II
Hematology Disease Topics & Pathways:
Leukemia, Anemias, AML, Follicular Lymphoma, Diseases, ALL, Biological, Adult, aplastic anemia, CML, Marginal Zone Lymphoma, Therapies, Mantle Cell Lymphoma, CMML, CNS Lymphoma, MDS, Non-Hodgkin Lymphoma, B-Cell Lymphoma, MPN, T-Cell Lymphoma, Study Population, Lymphoid Malignancies, Clinically relevant, Myeloid Malignancies, transplantation, stem cells
Sunday, December 2, 2018, 6:00 PM-8:00 PM
Hall GH (San Diego Convention Center)

Christopher Mazis, BS1*, Ioannis Politikos, MD1, Sean M Devlin, PhD2*, Molly Maloy, MS1*, Eric Davis, MPH3*, Candice Cooper1*, Melissa Nhaissi, MPH1*, Beth Suri3*, Deborah Wells3*, Sergio Giralt, MD1, Gunjan L. Shah, MD1, Marcel R.M. van den Brink, MD, PhD1, Nancy A. Kernan3, Andromachi Scaradavou, MD3* and Juliet Barker, MBBS1

1Adult Bone Marrow Transplant Service, Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, NY
2Department of Biostatistics and Epidemiology, Memorial Sloan Kettering Cancer Center, New York, NY
3Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, NY

Introduction: Optimal CB unit selection guidelines recommend consideration of CD34+ cell dose & 8-allele donor-recipient HLA-match. How graft characteristics for these parameters vary by patient (pt) race/ ethnicity, however, is not known.

Methods: We analyzed the infused graft & back-up unit cryopreserved total nucleated cell (TNC) x 107 & CD34+ x 105 cell content, the cell dose (incorporating pt weight), & 4-6/6 & 8-allele HLA-match by pt ancestry in CB transplant (CBT) recipients transplanted 1/2014-6/2018. Units were chosen based on banking practices (e.g. RBC depleted, standard cryo volumes), TNC & CD34+ dose & 4-6/6 & 8-allele HLA-match with dose usually taking priority over match given pt size at our center. The analysis included transplanted units (considered the best choice) & the next best high resolution typed back-up units (reserved but not shipped). Pt racial/ ethnic origins were prospectively obtained by detailed family history & grouped as previously described (Barker J. et al. BBMT 2010).

Results: The characteristics of 513 units chosen for 136 CBT recipients by pt ancestry are shown (Table 1). Pts had highly diverse origins including 70 (51%) non-Europeans. The 513 units included 270 units infused as the graft (134 doubles & 2 singles) & 243 back-up units (109 pts had 2 back-ups, 25 pts had one & 2 had none). Thus, 4 best units were analyzed in 109 pts (all double unit recipients), 3 best in 25 pts (all doubles), & 1 unit in 2 pts (both singles). The median weight of the 136 pts was 81 kg. Asian pts (median 68 kg) had a lower weight than other groups. The median TNC content of units for the 66 European pts was higher than that for the 70 Non-Europeans (218 vs 196, p = 0.004). Units chosen for Northwestern (NW) Europeans had the highest median TNC content (235) with lower TNC content in units for Southern Europeans (202), Asian (193), African (191) & White Hispanic (189) pts. Units chosen for European pts also had a higher median CD34+ cell content (162) than Non-Europeans (138), p = 0.004. NW Europeans had units with a higher median CD34+ content (198) & the lowest CD34+ content were those for African (124) & Middle Eastern pts (124). When patient weight was considered, median TNC/kg dose per unit was similar in European and Non-European pts (2.7 vs 2.6, p = NS). Units for NW Europeans had the highest median TNC dose (3.0) whereas those for African pts had the lowest TNC dose (2.4). Units for Europeans had a higher median CD34+ dose (2.0) than Non-Europeans (1.7) although this difference was not significant (p = 0.15). Additionally, similar to TNC dose, median CD34+ dose was highest in units for NW European pts (2.2) & lowest in units chosen for African pts (1.5). 89% of chosen units were 4/6 HLA-matched with no differences between Europeans & non-Europeans. Furthermore, the median 8 allele HLA-match was 5/8 (range 2-8/8) with no overall differences between units for Europeans and Non-Europeans (p = NS).

When only transplanted units were analyzed (Table 2), the median TNC & CD34+ contents were significantly lower in non-Europeans than Europeans (238 vs 216, p = 0.01 & 184 vs 160, p = 0.016). Overall, however, units received by Europeans vs non-European pts had similar TNC & CD34+ doses (p = NS). However, differences in the CD34+ content combined with differences in pt weights resulted in disparities in CD34+ doses by ancestry sub-group. NW Europeans (high weight, high CD34+ content) received the best CD34+ doses; lower CD34+ content in Asian pts was compensated for by their lower weight. African pts (high weight, low CD34+ content) received the lowest CD34+ doses. The median 8 allele HLA-match for all was 5/8 (range 3-8/8) with the exception of African pts [median 4/8 (range 3-7/8)]. Moreover, while 108 (40%) of transplanted units were 3-4/8 HLA-matched overall, there were marked differences between pt sub-groups with only 23% of units for NW Europeans being 3-4/8 vs 42% for southern Europeans, 46% for white Hispanics & 53% for Africans.

Conclusions: While CB significantly extends transplant access to racial & ethnic minorities, differences in cellular content translates to many minority pts receiving lower dosed units. There are also marked racial/ ethnic differences in HLA-match grade with African pts the most likely to receive highly mismatched units. This data supports ongoing funding of public CB banks to further increase the inventory of high dosed & better matched units for all but especially racial & ethnic minority pts.

Disclosures: Shah: Janssen: Research Funding; Amgen: Research Funding. Kernan: National Cancer Institute: Research Funding.

Previous Abstract | Next Abstract >>
*signifies non-member of ASH