Ashley, Lindsay

BACKGROUNDUmbilical cord blood (UCB) units collected from African Americans (AAs) have lower total nucleated cell (TNC) and CD34+ cell counts and are more likely to disqualify for banking compared to other ethnic groups. Furthermore, AAs have higher prevalence of 25‐hydroxyvitamin D (25(OH)D) deficiency. Given the importance of 25(OH)D in hematopoiesis, we examined the racial differences in UCB unit 25(OH)D content and its correlation with UCB cellular characteristics.STUDY DESIGN AND METHODSA total of 119 UCB units that did not meet the TNC count banking criteria were analyzed. Fifty‐one UCB units were collected from AA mothers and 68 from Caucasian mothers. We analyzed UCB volume, hematocrit (Hct), TNCs, mononuclear cells (MNCs), CD34+ cells, plasma 25(OH)D concentration, and progenitor clonogenic capacity measured by colony‐forming cell (CFC) assay.RESULTSCompared to Caucasians, AAs had significantly lower UCB 25(OH)D levels (p < 0.0001), TNCs (p = 0.002), MNCs (p = 0.026), and CD34+ cells (p = 0.026). Severe deficiency (25(OH)D < 10 ng/mL) was only detected in AAs. No difference in median CFC count/10,000 MNCs was detected between AAs and Caucasians. Independent of race, a significant association was detected between 25(OH)D level and TNCs (r = 0.193 p = 0.035) and Hct (r = 0.196 p = 0.033).CONCLUSIONThese results indicate the importance of 25(OH)D level as a racially independent predictor of UCB cellular characteristics and support further investigation of bioactive vitamin D and other predictors of hematopoiesis on cord blood quality.