Chilling controversy: cold-stored platelets for prophylactic transfusions

The US Food and Drug Administration recently licensed 14-day cold-stored platelets for bleeding patients. This policy change represents a reversal from the 1970s when cold-stored platelets were discontinued because of their short circulation time in healthy humans. This change will increase their availability in US hospitals with large trauma populations and in remote and rural settings in the United States. In some of these hospitals, cold-stored platelets will be the only platelets available. It is currently unclear whether patients with hypoproliferative thrombocytopenia who need platelet transfusion for prophylaxis benefit from cold-stored platelets. However, it is noteworthy that in recent clinical trials using room temperature-stored platelets, the transfusion interval in patients with hematologic and oncologic conditions can be as short as 1 transfusion per day, very similar to what one would expect to achieve with cold-stored platelets. Furthermore, the emphasis on the posttransfusion count increment and the platelet count as a transfusion trigger per se is questionable. In the PLADO trial, there was only a poor correlation between the morning platelet count and bleeding events, implicating other factors, such as red blood cells, coagulation factors, and vascular health, as possible culprits. In this perspective article, we review the history of cold platelets and the reason for their discontinuation, focus on recent clinical trial data using room temperature-stored platelets, and review the platelet count as a transfusion trigger. Overall, using cold platelets for prophylaxis may seem counterintuitive, but a closer look at the available data suggests that the indication expansion may hold more promise.