Cold Apheresis Platelets in PAS

A single hyperconcentrated apheresis platelet unit will be collected from a healthy adult volunteer subject using the Trima Accel® Automated Blood Collection System. Concurrent plasma will be collected. The platelet unit will be stored, not-agitated, for up to 20 days at 4°C in a suspension of 35% plasma and 65% PAS (Platelet Additive Solution). At the end of the storage period, the subject will return to receive an 111Indium Oxine (Indium 111, In-111) radiolabeled aliquot of their 4°C stored platelets. Follow-up samples from the subject will be collected approximately 2 hours post-infusion and on Days 1 (2X), 2 (2X), and 3 to calculate recovery and survival of the subject's 4°C stored platelets. The Day 1 and Day 2 the sample draws will be 2 - 10 hours apart. In addition to radiolabeled platelet recovery and survival measurements, various in vitro assays will be performed on the day of collection at the end of 4°C storage. One week after the infusion of the radiolabeled aliquot, the subject will return to receive a second radiolabeled aliquot of fresh platelets. To facilitate this, on the morning of the second infusion, the subject will return for collection of a 43 mL blood sample. The blood will be processed to obtain a fresh sample of the subject's platelets to serve as a control comparator. The platelets will be radiolabeled with In-111. The subject will return later in the day for infusion of the radiolabeled fresh 'control' comparator aliquot. Follow-up blood samples will be drawn at \~2 hours after the infusion on Day 0 and then on Days 1, 2, 3, 4 or 5, and 6 or 7 day post infusion to calculate recovery and survival of the subject's fresh vs. stored platelets.