Twenty-hour donor platelet recoveries for platelets prepared from MPR WB. (A) MPR WB followed by PL1-B F-LR of PRP. Two of 5 recipients accepted treated transfusions. There were no differences between means of pretreatment (53% ± 9%) and posttreatment (55% ± 8%) autologous platelet recoveries (P = .83), but there was a significant difference in means of pretreated and treated (27% ± 13%) autologous platelet recoveries (P = .002). (B) F-LR of WB followed by MPR of WB. All 10 recipients accepted treated donor platelets. There were no differences between means of prestudy (54% ± 5%) and poststudy (56% ± 8%) autologous platelet recoveries (P = .78), but there was a significant difference between pretreated and treated (46% ± 7%) autologous platelet recoveries (P = .03).