Reduction in adverse reactions to platelets by the removal of plasma supernatant and resuspension in a new additive solution (M-sol)

Leukodepletion reduces but does not eliminate adverse reactions to platelet concentrate (PC). As an alternative strategy, plasma reduction or washing of platelets should be considered. However, the efficacy of this strategy is still unclear. A total of 12 patients who experienced adverse reactions at a 29 to 100 percent reaction rate for plasma-PC were enrolled. The reactions were allergic reactions and nonhemolytic transfusion reactions, such as chills. Plasma-removed PC (W/R-PC), which was suspended in a recently developed additive solution (M-sol) containing less than 20 mL plasma, was prepared. W/R-PCs in M-sol were then transfused into patients after an overnight storage period; the occurrence of adverse reactions was monitored and 1- and 24-hour corrected count increment (CCI) values were evaluated. Although plasma-PC caused reaction in 12 patients, W/R-PC prevented reactions in 11 of 12 patients, with 1 patient having one minor allergic reaction of 15 transfusions. There was a significant difference in the incidence of reaction (p < 0.0001, Fisher's exact test). On a per-transfusion basis, the reaction rate for W/R-PC (1/156, 0.64%; 95% confidence interval [CI], 0.02%-3.5%) was reduced significantly compared to that for plasma-PC (117/276, 42%; 95% CI, 36%-48%; p < 0.0001). W/R-PC gave findings of satisfactory CCI at 1 hour (22,400 +/- 8,000/mu L) and 24 hours (15,400 +/- 8,000/mu L). No clinically evident bleeding episodes were recorded. W/R-PC suspended in M-sol in the presence of less than 20 mL plasma can be transfused safely and eliminate a wide range of adverse reactions to plasma-PC.