Biologic activity of RANTES in apheresis PLT concentrates and its involvement in nonhemolytic transfusion reactions

BACKGROUND: RANTES, one of the PLT-derived biologic response modifiers, accumulates in PLT concentrates (PCs) during storage and may play a causative role in nonhemolytic transfusion reactions (NHTRs) after PC transfusion. STUDY DESIGN AND METHODS: To investigate the association of RANTES with NHTRs, the biologic activity of RANTES in the supernatant of stored PC at the intravascular concentration expected after PC transfusion was assessed by examining chemotaxis and histamine release in human basophils. In addition, the levels of RANTES in PCs involved in NHTRs were compared with those in PCs causing no transfusion reactions. RESULTS: The supernatant of PC diluted to contain 1 nM RANTES significantly increased the migration of and release of histamine from basophils. Neutralizing antibody to RANTES suppressed the PC-triggered migration, but not histamine release. The levels of RANTES in PCs involved in NHTRs after PC transfusion were comparable to those in PCs that did not cause any transfusion reactions. CONCLUSION: RANTES that accumulated in PCs during storage was biologically active in a basophil chemotaxis assay at the intravascular concentration expected after PC transfusion. However, the NHTRs after PC transfusion were not simply related to the RANTES level in PCs.