Use of a cytokine-release assay to demonstrate loss of platelet secretory capacity during blood bank processing and storage

Abstract

Context. - The extent to which changes in secretory function contribute to the storage lesion of platelets (PLTs) prepared for transfusion is not well described. Objective. - To develop a cytokine-release assay for the assessment of PLT secretory capacity during the preparation and storage of PLTs. Design. - Small volumes of PLT-rich plasma and PLT concentrate (PC) were prepared from whole blood (WB; N = 4 donors). Aliquots of WB, PLT-rich plasma, and PC were treated with 20 μM adenosine diphosphate or saline (control). Samples of WB-derived PCs obtained from a regional blood center were similarly stimulated at various storage times (N = 10 units). Plasma levels of RANTES (chemokine ligand 5; regulated on activation, normal T cell expressed and secreted) and PLT aggregation were measured following agonist addition. Results. - Adenosine diphosphate stimulated RANTES release from PLTs in fresh WB on average by 4.1-fold (P < .001), in PLT-rich plasma by 4.7-fold (P = .002), and in PC by 1.3-fold (P < .001). Mean PLT aggregation decreased during processing from WB (95.6%) to PC (60.5%; P = .04). For blood center PCs, mean PLT aggregation decreased substantially from days 2 (41.0%) to 7 (2.3%; P < .001). Conclusions. - A cytokine-release assay revealed a diminution in PLT secretory capacity during PC processing and storage, with complete elimination by day 2 of storage. Loss of PLT aggregability occurred more slowly. The cytokine-release assay may be a useful endpoint for optimizing PLT preparation and storage.