Level of Inflammatory Mediators in Plasma of Platelet Concentrates and Beneficial Effect of Leucodepletion

Abstract

Platelet transfusions are frequently accompanied by febrile non haemolytic transfusion reactions (FNHTRs) up to 30%. Leucocytes, the most fragile and least stable of all principal blood cells, have been implicated in the pathogenesis of these FNHTRs occurring in patients being transfused by stored platelet concentrates (PCs) contaminated by these leucocytes. The aim of this study was to determine whether proinflammatory cytokines, acting as endogenous pyrogens, would accumulate in PCs during storage. We also aimed at studying the effect of filtration on release of some cytokines (e.g. IL-l, IL-6, IL-8 and TNF-a), as well as the effect of storage and filtration on platelet activation and release (by PF-4 assessment). This study included twenty freshly prepared PCs, each of which was further divided into two equal portions, one of which was filtered. Both unfiltered and flltered portions were stored up to five days at 22"C. Samples assayed for leucocyte count, platelet count, IL-1. IL-6, IL-8, TNF-a and PF-4 were withdrawn at different storage times (on days 0, 3 and 5) respectively. Results and statistical analysis revealed a significant decrease in cytokine levels in filtered units compared with the unflltered ones, that was directly correlated with the WBCs count reduction after flltration; whereas cytokine accumulation in the unftltered PCs proved to be time dependant. On the other hand PF-4 levels significantly increased in both unfiltered and filtered PCs throughout storage. It is to be concluded that prestorage leucocyte reduction of PCs highly improved the quality of these PCs by minimizing cytokine accumulation, thus consequently expecting to reduce frequency and severity of FNHTRs.