The mechanisms that underlie allergic transfusion reactions (ATRs) are not well characterized, but likely involve recipient, donor, and product factors. To assess product factors associated with ATRs, we investigated candidate mediators in apheresis platelet products associated with ATRs and controls.
STUDY DESIGN AND METHODS
Using bead-based and standard ELISA immunoassays, we tested supernatants from 20 consecutive apheresis platelet transfusions associated with ATRs and 30 control products for concentrations of mediators in 3 categories: acute inflammatory mediators, direct agonists of basophils and mast cells, and growth/priming factors of basophils and mast cells.
Median concentrations of the direct allergic agonists C5a, brain derived neurotrophic factor (BDNF), and CCL5 (RANTES) were 16.6%, 41.8%, and 13.9% higher, respectively, in the supernatant of apheresis platelet products that were most strongly associated with ATRs (P < 0.05 for each mediator). Other direct agonists (MIP-1α, MCP-1, eotaxin-1, IL-8) were similar between groups. Concentrations of acute inflammatory mediators and basophil growth/priming factors were also similar between groups (P > 0.2 for all associations).
The allergic agonists C5a, BDNF, and CCL5 may be mediators of ATRs in apheresis platelet products. Acute inflammatory proteins and basophil/mast cell growth and priming factors do not appear to be associated with apheresis platelet products that cause ATRs.