Development of a novel split, frozen, thawed and washed red cell component for intrauterine transfusion

Provision of red cells for intrauterine transfusion (IUT) can be challenging when the mother has an antibody to a high frequency antigen, as compatible allogeneic red cells may be scarce. The aim was to validate a novel component: split, frozen, thawed, washed and irradiated red cells for IUT, which could be used if foetal transfusion with maternal blood is necessary.

Six standard red cell concentrates were glycerolized on Day 5 and split into three smaller packs before freezing. A split from each donation was thawed and deglycerolized using the ACP215 and resuspended in saline-adenine-glucose-mannitol. The haematocrit was adjusted to IUT (70%-85%). The components, each approximately 80 mL, were immediately irradiated and tested for full blood count, haemolysis and supernatant potassium 8 and 24 h later.

At 8 and 24 h post manufacture, haemolysis was 0.20% (0.16%-0.25%) and 0.24% (0.18%-0.29%), respectively, and supernatant potassium was 20.3 mmol/L (15.1-27.1 mmol/L) and 43.1 mmol/L (33.5-58.4 mmol/L), respectively (mean [range]). Both haemolysis and potassium were within levels for standard irradiated IUT units.

Red cells split, frozen, thawed, washed and manufactured into IUT units and immediately irradiated are expected to be a beneficial component for very rare clinical cases.