Effects of stored platelets on cytokine release and recipient neutrophil respiratory burst

Abstract

Interleukin(IL)-8 generated ,from the stored platelets are known to be a cytokine to activate the neutrophils by priming effects, especially in patients with the primed neutrophils and to have a synergistic effect with other cytokines such as IL-6, IL-10 and tumor necrosis factor(TNF)-a. This study was conducted to evaluate the cytokine release from the stored platelets and their effects on neutrophil activation.

Ten units of fresh platelet concentrates and ten units of platelet-pheresis products were obtained from healthy donors and kept on agitator at room temperature. Samples were collected from the above preparations on day 0, 1, 3, 5 and 7 of storage for counts of leukocyte and platelet and assays of IL-8, IL-6, 11-- 10 and TNF-a using enzyme immunoassay. Platelet poor plasmas obtained from on day 0, 1, 3,- 5 and 7 of storage or recombinant human(rh) IL-8 were incubated with neutrophils from healthy donors and patients to measure the neutrophil respiratory burst using 2´,7´-dichlorofluoroscein diacetate by flowcytometry. The results were expressed as by Mean Channel Fluorescence(MCF) Ratio (MCF value of stored platelets/MCF value al negative control) and were summarized as below:

1. Mean leukocyte count of random platelet concentrates (1.230.32x109/L) was significantly higher than that of platelet-pheresis prod ucts(0.430.28 x 109/L, PC0.05):

2. The concentrations of 1L-8 and I1--6 were significantly higher in random platelet concentrates than in platelet-pheresis products. Especially, the concentration of IL-8 was progressively increased after 3 days of storage, depending on the storage time.

3. All of the MCF ratio of stored platelet preparations on day 1, 3 5 and `7 with patient´s or healthy,, ~z s donor´s neutrophils were not significantly different from those of day O(P>0.05). However mean McFl :

ratio in the patient group(1.1250.363) was significantly higher than that of healthy donor group(l.024 r F 0.274, P<0.05).

4. Priming effect of whole blood neutrophils were found with rhll.-8 when stimulated 10 ng/Ml for 5 minutes incubation, however, 11 ng/ml, 5 ng/ml, 10 ng/ml, 100 ng/ml for 30 minutes incubation(P<0.05).

In conclusion, stored random platelet concentrates contained high leukocyte count may relate to non-hemolytic transfusion reactions by increment of concentrations of cytokines, which have synergistic effects to neutrophil activation in primed recipients. Therefore, especially massive transfusion of stored random platelet concentrates should be avoided in already primed patients to prevent nonhemolytic transfusion reactions due to activated neutrophils.