Volume-reduced platelet concentrates: optimization of production and storage conditions

Plasma can be removed from platelet (PLT) concentrates (PCs) when volume reduction for PLT transfusion is indicated. Volume-reduced PCs are currently produced from pooled buffy coat (BC) PCs or apheresis PCs by pretransfusion volume reduction, followed by transfer to a syringe for immediate transfusion. We evaluated the maximal storage time of the volume-reduced PCs in gas-permeable containers.

Volume-reduced PCs were produced from BC-derived and apheresis PCs by hard-spin centrifugation. Supernatant was removed and the PLTs were resuspended in 20 mL of retained original PC and had PLT concentrations ranging from 10.8 × 10(9) to 13.8 × 10(9)  PLTs/mL. Volume-reduced PCs were stored either in syringes or in containers made from diethylhexyl phthalate (DEHP)-polyvinylchloride (PVC) or butyryl trihexyl citrate (BTHC)-PVC plastic. Units were sampled at t = 0, 1, 3, and 6 hours for in vitro measurements.

When prepared from 2-day-old PCs (n = 4), volume-reduced PCs from BCs in a syringe had a pH(37°C) of 5.76 ± 0.04 at t = 6 hours after volume reduction. In the DEHP-PVC container, pH was 5.85 ± 0.15 (not significant), and in the BTHC-PVC, 6.34 ± 0.16 (p < 0.001), at t = 6 hours. When made from 7-day-old PCs, pH was lower for all storage conditions: 5.68 ± 0.06 in the syringe, 5.70 ± 0.09 in the DEHP-PVC container (not significant), and 6.07 ± 0.24 in the BTHC-PVC container (p < 0.01) at t = 6 hours. Volume-reduced 2-day-old apheresis PCs had a pH of 6.47 ± 0.20 at t = 6 hours.

Adult-dose PCs derived from BC or apheresis can be volume-reduced to approximately 20 mL in a closed gas-permeable system. Volume-reduced PCs in BTHC-PVC containers retain a mean pH of more than 6.0 up to 6 hours after production. Syringes allow only 3 hours of storage.