Comparison of various dimethylsulphoxide-containing solutions for cryopreservation of leucoreduced platelet concentrates

Background and Objectives Leucoreduced platelet concentrates (LR‐PCs) can be stored at 20–24 °C for 5–7 days. When LR‐PCs are cryopreserved they can be stored for several years. For cryopreservation to become applicable in blood‐bank practice, an off‐the‐shelf cryoprotectant is needed that can be added to the LR‐PC in a sterile manner. For this, we varied the composition of the cryopreservation medium and studied various parameters of cryopreserved LR‐PCs for up to 24 h after thawing at room temperature. Materials and Methods LR‐PCs in plasma or Composol were concentrated and divided into 2 units. To each unit, an equal part of 10% dimethylsulfoxide (DMSO) in plasma, Composol with or without 5% albumin, or GPO (pasteurized plasma‐protein solution) was added. Freezing occurred at 1 °C/min and LR‐PCs were placed in the vapour phase of nitrogen. LR‐PCs were thawed at 37 °C and stored at room temperature. LR‐PCs were tested for morphology, platelet recovery, swirling effect, and activation antigens at various time‐points thereafter. Results LR‐PCs in 100%, 65% and 50% plasma supplemented with Composol showed good morphology scores (> 250), limited CD62P expression (