Low cytokine contamination in buffy coat-derived platelet concentrates without filtration

Cytokines (interleukin [IL]-1 beta, IL-6, and tumor necrosis factor [TNF]) generated by white cells during the storage of platelet concentrates can cause febrile nonhemolytic transfusion reactions. The high rate of febrile reactions reported in other studies was not observed in the patients in the authors' center. This discrepancy prompted the determination of cytokine levels in buffy coat-derived platelet concentrates.

Platelet concentrates were produced from buffy coats by a standard large-scale production process. Buffy coats were separated from the red cell and plasma components, and then platelets were recovered from the buffy coats by a soft-spin procedure. Levels of cytokines (IL-1 beta, IL-6, IL-8, and TNF) were determined with commercial enzyme-linked immunosorbent assays.

In platelet concentrates produced by the buffy coat method, IL-1 beta, IL-6, IL-8, and TNF were observed at or below the detection limit of current enzyme-linked immunosorbent assays after 5 days' storage at 22 +/- 2 degrees C. Therefore, prestorage filtration had no measurable effect on cytokine levels. In controls, IL-1 beta, IL-6, IL-8, and TNF were quantitatively detected after exogenous addition of recombinant cytokines or exposure to lipopolysaccharide.

Platelet concentrates prepared from buffy coats may be virtually free of cytokines (IL-1 beta, IL-6, IL-8, and TNF) during 5 days of storage. Filtration is not required to reduce the recipient's cytokine exposure via such platelet concentrates.