Optimizing donor selection for public cord blood banking: influence of maternal, infant, and collection characteristics on cord blood unit quality

Abstract

Background: Banked unrelated donor umbilical cord blood (CB) has improved access to hematopoietic stem cell transplantation for patients without a suitably matched donor. In a resource-limited environment, ensuring that the public inventory is enriched with high-quality cord blood units (CBUs) addressing the needs of a diverse group of patients is a priority. Identification of donor characteristics correlating with higher CBU quality could guide operational strategies to increase the yield of banked high-quality CBUs.

Study design and methods: Characteristics of 5267 CBUs donated to the Carolinas Cord Blood Bank, a public bank participating in the National Cord Blood Inventory, were retrospectively analyzed. Eligible CBUs, collected by trained personnel, were processed using standard procedures. Routine quality and potency metrics (postprocessing total nucleated cell count [post-TNCC], CD34+, colony-forming units [CFUs]) were correlated with maternal, infant, and collection characteristics.

Results: High-quality CBUs were defined as those with higher post-TNCC (>1.25 × 10(9)) with CD34+ and CFUs in the upper quartile. Factors associated with higher CD34+ or CFU content included a shorter interval from collection to processing (<10 hr), younger gestational age (34-37 weeks; CD34+ and CFUs), Caucasian race, higher birthweight (>3500 g), and larger collection volumes (>80 mL).

Conclusions: We describe characteristics identifying high-quality CBUs, which can be used to inform strategies for CBU collection for public banks. Efforts should be made to prioritize collections from larger babies born before 38 weeks of gestation. CBUs should be rapidly transported to the processing laboratory. The lower quality of CBUs from non-Caucasian donors highlights the challenges of building a racially diverse public CB inventory.

Figure 1

Impact of infant estimated gestational age on the CFU, CD34⁺ and post-TNCC content. In Panels A–C, the adjusted mean CFU (Panel A), CD34⁺ (Panel B) and post-TNCC (Panel C) is shown in relationship to infant gestational age after adjusting for infant race/ethnicity, birth weight, gender, collection volume, delivery type and maternal age. Only significant p values are shown. Whisker plots represent the 95% Confidence Intervals.

Figure 2

Comparison of the CFU, CD34⁺, and post-TNCC concentrations for Caucasian and African American infants. In Panels A–C, the adjusted mean CFU per ml (Panel A), CD34⁺ per ml (Panel B) and post-TNCC per ml (Panel C) is shown in relationship to race for infants of Caucasian and African American race, respectively, after adjusting for infant gestational age, birth weight, gender, collection volume, delivery type and maternal age. Only significant p values are shown. Whisker plots represent the 95% Confidence Intervals.

Figure 3

Impact of infant birth weight on the CFU, CD34⁺ and post-TNCC content. In Panels A–C, the adjusted mean CFU (Panel A), CD34⁺ (Panel B) and post-TNCC (Panel C) with respect to birth weight is shown after adjusting for infant race/ethnicity, gestational age, gender, collection volume, delivery type and maternal age. Only significant p values are shown. Whisker plots represent the 95% Confidence Intervals.

Figure 4

Impact of time to processing on CFU, CD34⁺ and post-TNCC content. In Panels A–C, the adjusted mean CFU (Panel A), CD34⁺ (Panel B) and post-TNCC (Panel C) by time to processing is presented after adjusting for infant race/ethnicity, gender, gestational age, birth weight, collection volume, delivery type, and maternal age. Only significant p values are shown. Whisker plots represent the 95% Confidence Intervals.

Figure 5

Considering the potency (CFU content) along with post-TNCC in donor selection. The relationship between post-TNCC and the CFU content (i.e. potency) is shown for the study cohort (n= 5267 CBUs). The vertical lines represent (from left to right): the minimum post-TNCC required for banking (0.9×10⁹), an intermediate post-TNCC (1.25 × 10⁹), and the median post-TNCC of CBUs selected for transplantation (1.75×10⁹). Quartiles for the CFU content are also represented [upper quartile: red circle, second quartile: green triangle, third quartile +: gold, and lower quartile: blue x]. Region A refers to CBUs with post-TNCC>1.75x 10⁹ and CFU in the highest quartile. Region B refers to post-TNCC 1.25–1.75×10⁹ with CFU in the highest quartile. Region C refers to CBUs with post-TNCC >1.75×10⁹ and CFU in the lower three quartiles.