Survival of baboon biotin-X-N-hydroxysuccinimide and 111In-oxine-labelled autologous fresh and lyophilized reconstituted platelets

Background and Objectives  In accordance with Food and Drug Administration (FDA) regulations, platelets can be stored in the liquid state at 22 °C for only 5 days. Platelets frozen with 6% dimethylsulphoxide (DMSO) can be stored at −80 °C for 2 years, and platelets frozen with 5% DMSO can be stored at −150 °C for 3 years. Studies are being conducted to determine the effects of lyophilization of platelets. In the present study, we assessed the survival of autologous lyophilized-reconstituted platelets in the baboon. Materials and Methods  We studied fresh baboon platelets and baboon platelets that had been treated with paraformaldehyde, frozen, lyophilized, thawed and reconstituted. Aliquots of these platelets were labelled with 111In-oxine or biotin-X-N-hydroxysuccinimide (biotin-X-NHS) before autotransfusion, and measurements were made of the in vivo recovery and lifespan. We also evaluated the response of fresh and lyophilized platelets to in vitro agonists by measuring the level of platelet surface markers and heterotypic aggregates in the peripheral blood following the autotransfusions. Results  The 111In-oxine- or biotin-X-NHS-labelled lyophilized, reconstituted platelets exhibited survival times of less than 15 min. These platelets did not respond to stimulation with agonists to decrease platelet GPIb and increase platelet P-selectin and platelet GPIIb-IIIa levels 1 min post-transfusion and they accumulated more procoagulant factor V than did the fresh platelets. Conclusions  Lyophilized reconstituted baboon platelets labelled with 111In-oxine or biotin-X-NHS before autotransfusion exhibited an in vivo circulation time of less than 15 min. Further study of the lyophilized, reconstituted platelets is required to evaluate their haemostatic function.