Cryopreserved platelets: a narrative review of its current role in transfusion therapy

To review the current role of cryopreserved platelets (CPP) in transfusion medicine. Background: The short shelf life of platelet concentrates (PCs) provokes logistic problems in providing timely PC transfusions during long holiday periods when long or major transportation barriers exists (severe weather, military operations…) or for patients highly alloimmunized by HLA/HPA antibodies. In the European Union the only approved strategy authorized to circumvent the limited storage time of PCs is the cryopreservation using 6% dimethyl sulfoxide (DMSO), at temperature of –80 ℃ or below. Methods: A review of articles referenced in PubMed published in English before 2020 studying the effect of cryopreservation on platelets in vivo and in vitro was performed. Conclusions: Using in vitro techniques available to characterize platelets, significant changes in the structure and function of CPP after thawing are detected. The changes detected suggest that cryopreservation provokes an increase in the procoagulant activity of platelets. However, in vivo studies in healthy volunteers and in patients, have shown the efficacy and safety of the transfusion of CPP in different clinical scenarios. Nevertheless, its current use is limited to situations where liquid stored platelets is not available mainly in military operations, for patients with complex HLA/HPA alloimmunization or for patients with massive bleeding.