This post was updated on March 12, 2018, to incorporate new data

Platelets are very sensitive cells and activate easily. This is part of their function as immune and hemostatic cells. Due to the standardization of the donation and production process, it is assumed that transfusions primarily contain non-activated platelets. However, investigations into the activation status of platelet transfusions at hospital blood banks reveal a surprisingly high prevalence of activated platelets. Five major hospitals across the US studied the platelet activation status of their inventories. On average, they found that nearly 40% of platelets are activated.

Even more surprising is the variability between the individual centers ranges from activation rates of 23% to 50%.

From these investigations so far two important conclusions can already be drawn:

1) A significant number of platelet transfusions in the US contain activated platelets

2) The percentage of activated platelets in inventory varies from hospital to hospital.

These observations have inspired more hospital blood banks to screen their inventory. We will be continuously updating this information as new platelet activation status data become available.