Quality of Cord-Blood Units and Hematological Recovery After Intra Bone CBT Are Not Influenced by the Bank of Origin and by the Time of Cryopreservation
Authors: Kurita Naoki , Frassoni Francesco , Sacchi Nicoletta , Cossu Claudia , Serio Alberto , Cilloni Daniela , Podestà Marina 
Published: October 2019

Abstract
Abstract 4400

BACKGROUND:
Cord-blood transplantation (CBT) is an effective option for both malignant and non-malignant hematological diseases and its increasing number in the last years has enlarged the frequency of the use of cord-blood units (CBUs) trough international borders in order to maximize the opportunity of identifying optimal CB unit. Since there is no global standard regarding cord-blood quality control, the quality of CBUs can be affected by the bank of origin. In addition, few information are disposable on the cord blood engraftment capacity after long-term cryopreservation. In this study, we evaluated whether the origin and the age of CBUs may influence the quality of CBUs and post-transplant hematological recovery.

METHODS:
CBTs with single unit were performed at San Martino Hospital in Genoa for hematological malignancies using an intra-bone cord blood transplant technique. Just before infusion, a small sample of the CBU was obtained and post-thawing number of total nucleated cells (TNCs), CD34 positive cells, and colony-forming cells (CFCs) were characterized. Median pre-freezing number of TNCs and CD34-positive cells were 2.32 (1.15 – 4.52) × 109 and 9.3 (2.4 – 27.24) × 106, respectively. Recovery of neutrophil and platelet were compared according to the origin and the age of each CBU.

RESULTS:
95 CBUs were tested. The bank of origin of CBUs was Europe (n = 45), the United States (n = 40), and other regions (n = 10). Median age of CBUs was 4.9 (0.4 – 11.8) years; CBUs originated from European bank were significantly older than CBUs from other regions (5.9 years vs 3.8 years, p value of unpaired t-test < 0.001). Median post-thawing number of TNCs, CD34 positive cells, and CFCs were 2.3 (0.74 – 4.5) × 109 cells, 1.1 (0.23 – 2.7) × 107 cells, and 1.8 (0.0 – 12) × 106 cells, respectively. These values did not differ considering older (> 4.9 years) CBUs or younger CBUs (< 4.9 years) or the bank of origin. Rate and median time of neutrophil and platelet engraftment was as follows: younger CBUs: 24 and 34 days, older CBUs: 25 and 35 days, respectively (Figure 1,3). Hematological recovery was not influenced by the bank origin of CBUs as well, namely, rate and time of neutrophil and platelet engraftment was, 22 and 34.5 days (Europe), 22 and 35 days (the United States), 24 and 42 days (the other region), respectively (Figure 2,4).

CONCLUSION:
Although in our experience time of cryopreservation of CBUs was significantly dependent from bank of origin, the origin and the age of CBUs have little impact on post-thawing values of TNCs, CD34 positive cells, and CFCs. In addition, hematological recovery after transplant was not influenced by the origin or by the age of CBU. These data suggest that quality control of CBU is working well regardless of the bank origin.

Disclosures:
No relevant conflicts of interest to declare.