The Primary Purpose of This Study is to Determine if Biotin, Vitamin B7 is an Effective Way to Label Platelets in Survival and Recovery Studies.

Overview

This is a platelet transfusion study. The primary purpose of this study is to determine if Biotin, vitamin B7 is an effective way to label platelets in survival and recovery studies. This study involves using a radioactive material as well as Biotin added to platelets to track platelets in the blood. The platelets will be collected using an apheresis procedure, labeled with biotin, and stored for 3 days. After the storage period, a radioactive material will be added to a small amount of the stored biotin-treated platelets. The radiolabeled platelets will be given back to donor and follow-up blood draws will be done to see how many of the platelets are circulating.

To evaluate the hypothesis that biotinylation of platelets stored at room temperature for 3 days is equivalent for the assessment of in vivo recovery and survival to radiolabeled platelets. The post-transfusion recovery and survival of autologous biotinylated 3-day platelets will be measured in comparison with those of autologous radiolabeled 3-day platelets from the same source. In the same fashion, "fresh" autologous biotinylated platelets, will be compared to "fresh" radiolabeled platelets according to Food and Drug Administration, FDA guidance for platelet testing. Healthy volunteers will be asked to donate a platelet unit, which will be stored for 3 days. On the day of radiolabeling, the investigators will collect samples for metabolomics and functional assessment. The volunteers will return on day 3 and receive a radiolabeled and biotinylated aliquot of the stored unit, as well as a fresh radiolabeled platelet aliquot. The investigators will collect blood samples over the following 12 days to determine recovery, survival, function, metabolomic changes, and antibody coating of the stored platelets. During a 6-month follow-up period, the investigators will collect samples for platelet count, biotin, and platelet antibody detection, and biotin levels if antibodies are present at 1, 3, and 6 months to exclude harmful effects of the biotin-labeled platelets on healthy individuals.