Optimal protocol for preparation of leukocyte-poor red cells with a blood cell processor

The optimal red cell override (RCO) protocol for preparation of leukocyte-poor red cells (LPRCs) with a blood cell processor (IBM 2991) was studied. By a four-step process, including determining leukocyte (WBC) and red cell (RBC) distributions in the processing bag after centrifugation, the optimal RCO sequence was determined. The "effectiveness index" of WBC removal also was used for comparison of the efficiencies of various RCO protocols. In this way, a four-cycle RCO sequence of 1.5/1.5/1.5/1.5 was found to be optimal for washing 130-ml units of concentrated red cells (CRCs). This protocol yielded LPRCs with means of 5.4 percent of WBCs remaining and an 84.2 percent recovery of RBCs. The optimal RCO sequence of 2.0/2.0/2.0/2.0 for washing 260-ml units of CRC gave LPRCs with means of 6.2 percent of WBCs remaining and an 87.8 percent recovery of RBCs.