title: Therapeutic effectiveness of frozen platelet concentrates for transfusion.
abstract: Six patients received platelet concentrate transfusions from their HLA-identical siblings. Platelet concentrates were administered either fresh, or after being frozen in 10% dimethylsulfoxide, at a slow controlled rate (1 degree C/min) or rapidly (approximately 8 degrees C/min) in the vapor-phase of a liquid nitrogen refrigerator. The median freeze-thaw loss was 13.5%. The mean 1-hr and 20-hr corrected increments in platelet count were calculated for fresh platelet concentrates transfused before and after transfusion with controlled-rate frozen and vapor-phase frozen platelet concentrates. There was no significant difference among the first and second transfusion of fresh platelet concentrates, nor was the difference observed between fresh and controlled-rate frozen platelet concentrates significant. The difference between fresh and vapor-phase frozen platelet concentrates, and between controlled-rate frozen and vapor-phase frozen platelet concentrates were highly significant (p < 0.01). In vitro tests of aggregation using ristocetin and platelet ultrastructural studies paralleled the transfusion experience. Our results indicate that HLA-identical platelet concentrates can be successfully frozen and thawed for transfusion if a slow, controlled rate of freezing is employed. The use of HLA-identical frozen platelet concentrates may be important in emergency situations for the refractory patient and potentially for the establishment of a platelet concentrate bank.
mesh_terms: D000741:Anemia, Aplastic / Q000628:therapy; D001792:Blood Platelets / Q000276:immunology / Q000502:physiology; D001803:Blood Transfusion; D005615:Freezing; D006650:Histocompatibility Testing; D006801:Humans; D007945:Leukemia, Lymphoid / Q000628:therapy; D009101:Multiple Myeloma / Q000628:therapy; D017713:Platelet Transfusion; D013048:Specimen Handling; D013997:Time Factors