Transfusion of cryopreserved platelets exacerbates inflammatory liver and lung injury in a mice model of hemorrhage.

Background: Platelets are essential for primary hemostasis and also play an important role in inflammatory reactions. The hemostatic property of cryopreserved platelets (CPPs) has been confirmed in the treatment of bleeding casualties, but inflammatory injury induced by CPP transfusion is relatively unclear. We aim to investigate the effects of CPP transfusion on inflammatory organ injury in mice after hemorrhage.

Methods: Mice were subjected to a volume-controlled hemorrhage over 1 hour, and then were transfused with fresh platelets (FPs), Liquid-stored platelets (LPPs), CPPs, or fresh frozen plasma (FFP, control). At 6 hours posttransfusion, mice were sacrificed, and blood and tissues were sampled. Tissue sections were examined histologically and by immunohistochemical staining of neutrophils and macrophages. Plasma alanine aminotransferase, hepatic myeloperoxidase activity and inflammatory cytokine levels were measured.

Results: Transfusion of stored platelets (LPPs and CPPs) caused more serious histological injury in liver and lung compared with FPs and FFP (p < 0.05). However, kidney histological injury was similar among groups. Significantly higher numbers of Ly-6G-positive neutrophils were detected in liver and of F4/80-positive macrophages in liver and lung of mice transfused with LPPs or CPPs compared with FPs or FFP (p < 0.05). Transfusion of CPPs caused the most severe inflammatory liver injury, as reflected by alanine aminotransferase levels, hepatic macrophage infiltration, and hepatic myeloperoxidase activity and inflammatory cytokine levels (macrophage inflammatory protein-2, tumor necrosis factor-α, and interleukin-1β).

Conclusion: Cryopreserved platelet transfusion is more likely to aggravate hemorrhage-induced liver and lung injury by activating macrophage and facilitating neutrophil infiltration into hepatic tissues.