Autologous transfusion recovery of WBC-reduced high-concentration platelet concentrates

BACKGROUND: This study evaluates the recovery and survival of high-concentration platelets (HCPs) compared to standard apheresis platelets (APCs) in a double-label autologous human system. METHODS: Nine HCP units paired with APC units were stored, labeled with either Cr-51 and In-111, and returned, and recovery and survival were determined. Standard in vitro platelet biochemical and functional parameters were monitored over the storage period and evaluated in a secondary analysis. RESULTS: Three each HCP units containing more than 2.2 x 10(11), 1.5 x 10(11) to 2.1 x 10(11), and 0.8 x 10(11) to 1.1 x 10(11) platelets in 59.4 +/- 2.5 mL were stored for 1, 2, or 5 days, respectively, and simultaneously with matched APC units (3.8 x 10(11) platelets, 282 mL). Recoveries were 72.3 +/- 8.6, 60.8 +/- 14.6, and 52.5 +/- 6.7 percent for HCPs, respectively; and 59.4 +/- 6.4 percent for APCs (p = 0.37). HCP survivals were 202.0 +/- 14.9, 204.9 +/- 10.2, and 162.6 +/- 17.0 hours; APC survivals were 155.4 +/- 20.3 hours (p = 0.001). Secondary analysis with P-selectin added as a predictor in the model resulted in significant difference in recoveries for Day 1 HCPs versus Day 5 APCs (p = 0.024) with no difference shown for HCPs on Days 2 or 5 versus APCs. No significant difference was found in survival (p = 0.16). CONCLUSION: HCPs may be stored 24 hours for high yield, 48 hours for intermediate yield, and up to 5 days for yields less than 1.6 x 10(11) platelets per bag with equivalent to superior recovery and survival of platelets in the autologous transfusion model compared to APCs.