Platelets Expressing P-Selectin and Platelet-Derived Microparticles in Stored Platelet Concentrates Bind to PSGL-1 on Filtrated Leukocytes

Abstract

The levels of interleukin-6 and platelet-derived microparticles (PMPs) were measured in the blood of 137 pa tients with side effects from platelet concentrate (PC) transfu sion with leukocyte removal filtration, P-selectin-expressing platelet and PMPs in stored PC before and after the filtration, and filtered leukocytes positive for P-selectin glycoprotein li gand-1. The side effects, which were observed in 203 transfu sions for 84 patients with hematologic disease and 53 patients with nonhematologic disease with no significant difference be tween the two groups, included urticaria (75.9%), erythema (18.7%), and fever (17.2%), but no anaphylactic reactions. The levels of interleukin-6 and PMP correlated in both groups, and were significantly higher in the hematologic disease group than in the nonhematologic disease group. The level of PMP, but not interleukin-6, was significantly higher for patients testing posi tive for allergic reaction than for those testing negative. In the stored PC prior to filtration, the level of interleukin-6 was normal. The level of P-selectin-expressing platelets and PMPs was elevated before filtration, but was significantly lower after filtration. Taken together, the results suggest that PMP is in volved in the generation of transfusion reactions, and indicate that both platelets and PMP displaying P-selectin bind to P- selectin glycoprotein ligand-1 of leukocytes retained by the leukocyte filter.