Characteristics of thawed autologous umbilical cord blood

Abstract

BACKGROUND: Autologous umbilical cord blood (AutoUCB) has historically been cryopreserved for potential use in hematopoietic transplantation. Increasingly, private AutoUCB banking is performed for therapies unavailable today. A Phase I trial using AutoUCB treatment for early pediatric Type 1 diabetes afforded us an opportunity to analyze characteristics of AutoUCBs. STUDY DESIGN AND METHODS: Twenty AutoUCBs from AABB-accredited private cord blood banks (CBBs) were evaluated for collection, processing, cryopreservation, and thaw characteristics. Using a standardized thaw-wash method, AutoUCBs were assessed for viable total nucleated cells (vTNCs), viable CD34+ (vCD34+), and colony-forming unit-granulocyte-macrophage counts. Postthaw %vTNC recoveries were compared against processing characteristics and analyzed according to processing method, cryopreservation volume, concentration, container, and length of storage. RESULTS: AutoUCB collection volumes (19.9-170 mL), cryopreserved TNC counts (7.6 × 10(7) -3.34 × 10(9)), %TNC processing recoveries (39%-100%), postthaw %vTNC recoveries (58%-100%), and %vCD34+ recoveries (26%-96%) varied widely. Regarding cell dose requirements, only 11% of evaluable AutoUCBs achieved the minimum TNC count of at least 9.0 × 10(8) to meet the National Cord Blood Inventory banking threshold, and only 50% met the minimum of 5.0 × 10(8) TNC count for Food and Drug Administration cord blood licensure eligibility. %vTNC recoveries correlated with %vCD34+ recoveries (R = 0.7; p = 0.03). Length of storage, cryopreservation volume, concentration, and container type did not affect postthaw %vTNC recoveries. CBB processing method, however, was associated with %vTNC postprocessing recoveries, with unmanipulated and plasma-depleted AutoUCBs having the highest postthaw %vTNC recovery, followed by RBC-depleted and density gradient-separated AutoUCBs. CONCLUSION: The high variability and low counts found in AutoUCB banking suggest that further standardization of characterization, collection, and processing procedures is needed.