Preparation, Freezing, Transportation, Thawing and Quality Control of Human Platelets Isolated by Mechanical Cell Separating Systems and Frozen with Dimethylsulfoxide in a 300 Milliliter Polyvinylchloride Plastic Bag with Removal of the Supernatant Dmso Prior to Freezing

platelet studies were done in healthy male voluntecrs and in thrombocytopcnic patients. Some of the platelets used in the study were isolated by mcclanical apheresis using .itn"t the Haemonetics blood processor 30, the IBM btood prooGsor 2997 or the Fenwal C$3000 blood prooessor before freezing" Other platelets wene isolatod from individud units of whole blood-and pooted before freezing. The platelets werc froicn with a 696 cryoprotec tant (Dlv{SO) in a polyvinytchloride (PVC) plastic bag or a potyolefin plastic bag at -80'C in a mechanical freezer and stored for as long as 3 years. Some of the frozen platelets were transported in dry ie in polystyr€ne foam containers to determine'whether they would be adversely afecteO by such treatment. Platelet recovery after freezing; thawing and washing was about lilqf'.In the healthy male volunteers, in vivo recovery of autologous platelets l-zh after transfirsion was about 33%, and the life span was about 8 days. In the thrombocytopenic patients, in vivo recovery values were 50% of those from fresh platelets. The transfusion of previously frozen washed platelets reduced clinical bleeding in the thrombocytopenic patients with bleeding. There was no evidence of quality deterioration in platelets after storage at -80'C for at least 2 years, as determined from in vitro recovery and in vivo survival values, norwas there any adverse effect as a result of shipment of the frozen platelets in dry ice in polystyrene foam containers from one facility to another. I This work was supported by the US Narry under Offrce of Naval Research Contract N00014-79-C-0168 with funds provided by the Navat Medical Research and Development Command. The opinions or assertions contained herein are those of the authors and are not to be construed as offrcial or reflecting the views of the Nalry Department or Naval Sewicc at large-