The Role of Plasma from Platelet Concentrates in Transfusion Reactions

Comment: Febrile nonhemolytic transfusion reactions occur in 5–30% of platelet transfusions. This carefully conducted study indicates that a significant proportion of these reactions may be related to the plasma supernatant in the platelet concentrates. It suggests that toxic soluble products, such as interleukins, may be produced by white cells during storage and released into the supernatant. These observations would explain why removing leukocytes from the product before transfusion is not effective in preventing reactions in all patients. However, depleting platelet concentrates before storage may be effective in preventing these reactions. Larger scale studies would be needed to demonstrate wheuier this would be efficacious and cost-effective. It should be noted that even this type of treatment will not prevent all reactions. Several patients in this study reacted only to the cellular component of the platelet product, suggesting that there are other mechanisms for reaction in some patients. The investigators in this study found that interleukin-1β and interleukin-6 levels in the plasma supernatant correlated with severity of reactions. However, these were the only cytokines that were assayed. Multiple other bioreactive substances could in fact be involved in these reactions. Further studies involving specific blockers of cytokines would be necessary to demonstrate which exact substances are responsible for these reactions.