Storage of platelets in additive solutions: the effects of magnesium and potassium on the release of RANTES, beta-thromboglobulin, platelet factor 4 and interleukin-7, during storage.

BACKGROUND AND OBJECTIVES

Several studies have suggested that the accumulation of cytokines during storage of platelet concentrates may mediate non-haemolytic transfusion reactions. Prestorage leucodepletion can prevent the release of cytokines from white blood cells during storage, but not the release of platelet-derived cytokines. Therefore, we investigated whether the addition of magnesium and potassium to platelets stored in a platelet additive solution (PAS) would affect the generation of cytokines during platelet storage.

MATERIALS AND METHODS

Platelets were prepared from buffy coats using different suspension media: plasma; 70% PAS-III + 30% plasma; 70% PAS-III supplemented with magnesium and potassium +30% plasma; and 80% PAS-III supplemented with magnesium and potassium +20% plasma. The levels of certain cytokines--regulated on activation, normal, T-cell expressed, and secreted (RANTES), beta-thromboglobulin (beta-TG), platelet factor 4 (PF4) and interleukin-7 (IL-7)--were measured by enzyme-linked immunosorbent assay (ELISA) on days 1, 5 and 7.

RESULTS

The concentrations of RANTES, beta-TG, PF4 and IL-7 increased, during storage, in all units. The increase was significantly greater in units stored in 70% PAS-III +30% plasma than in the other three suspension media. The storage of platelets in 70% PAS-III supplemented with magnesium and potassium +30% plasma significantly reduced the concentrations of platelet derived-cytokines during storage, as compared to platelets stored in 70% PAS-III + 30% plasma alone.

CONCLUSIONS

The concentrations of platelet-derived cytokines increased, to a significantly greater extent, when platelets were stored in PAS-III than in plasma. However, when magnesium and potassium were added to PAS-III, the concentrations of platelet-derived cytokines obtained during storage were about the same as those produced by platelets stored in plasma.