Allogeneic cord blood red blood cells: assessing cord blood unit fractionation and validation

For neonates and preterm infants, in whom a transfusion dose is low, the use of red blood cells (RBC) from cord blood appears to be feasible. Standardisation of fractionation and identification and assessment of quality control parameters for such RBC are still lacking.

We describe the process used to obtain RBC from cord blood for transfusion purposes, including quality controls to evaluate fractionation performance and the effects of storage. The cord RBC, to which SAG-M was added, were sampled on the day of fractionation, and 7 and 14 days (end of storage) later in order to measure the complete blood count, biochemical parameters and residual white blood cells. We also assessed microbial contamination.

Data relative to 279 cord blood units were evaluated. The median gestational age at collection was 40 weeks (interquartile range [IQR] 39.1-40.7) and the median volume was 90 mL (IQR 81-103). Units were subjected to automated fractionation with Compomat, and packed RBC were suspended in SAG-M solution. The median volume of the SAG-M-suspended units was 31 mL (IQR 24.0-38.1) and the median haematocrit was 54.2% (IQR 49.4-59.5). The median volume after leukoreduction was 22 mL (IQR 17-28), with the volume decrease being similar in units leukoreduced before (n=75) or after (n=204) storage. The haematocrit of leukoreduced units was higher than that of buffy coat-depleted units. Storage at 2-6 °C for 14 days was accompanied by an increase of potassium levels and percentage of haemolysis. Microbial cultures were positive for 2.9% of the collected units.

Fractionation of whole cord blood can provide RBC concentrates with similar baseline characteristics as units from adults. The transfusion dose and quality of the units appear safe and suitable for clinical use in neonates, with a satisfactory haematocrit and residual white blood cell content, despite a very variable collection volume.