BACKGROUND: Several studies have suggested that cytokine accumulation during storage of platelet concentrates (PCs) may mediate nonhemolytic febrile transfusion reactions and that a reduction in WBC numbers prevents the generation of cytokines. Despite efforts to minimize WBC contamination in apheresis PCs, high numbers of WBCs and increased cytokine levels may still occur, depending on the quality of the apheresis device employed.

STUDY DESIGN AND METHODS: This study was undertaken to investigate whether PCs collected with WBC‐reduction devices (Spectra LRS, COBE;or MCS+ LDP, Haemonetics) were sufficiently depleted of WBCs to limit cytokine accumulation during storage. The study evaluated 1) the levels of cytokines of WBC and platelet origin in two types of apheresis PCs during storage and 2) the effects of prestorage filtration on cytokine levels in the Spectra LRS PCs.

RESULTS: In the Spectra LRS PCs, low levels of IL‐6, IL‐8, and monotype chemoattractant protein 1 (MCP‐1) were detected in Day 1 PCs, and they remained consistent during the shelf life. RANTES, platelet factor 4 (PF4), β‐thromboglobulin (β‐TG), and transforming growth factor (TGF)‐β1 were also detected in these PCs, and their levels increased significantly on storage. Prestorage filtration of Spectra LRS PCs did not further reduce the levels of IL‐6, IL‐8, MCP‐1, PF4, β‐TG, and TGF‐β1 in the filtered component. In the MCS+ LDP PCs, IL‐6 was detected on Day 1, and its level increased significantly on storage, whereas the levels in the Spectra PCs remained steady. IL‐8 levels were lower in MCS+ LDP PCs than in Spectra LRS PCs of the same age. MCP‐1 levels were similar in both products on Day 1 and marginally increased in stored MCS+ LDP PCs. Substantial amounts of RANTES, PF4, β‐TG, and TGF‐β1 occurred in Day 1 MCS+ LDP PCs, and, on storage, these levels rose significantly.

CONCLUSION: Despite a significant reduction in levels of WBC‐derived cytokines, platelet‐derived cytokines were present in different amounts in the two products.