Effects of storage time prolongation on in vivo and in vitro characteristics of 4°C-stored platelets.

Background: Cold (4°C)-stored platelets are currently under investigation for transfusion in bleeding patients. It is currently unknown how long cold-stored platelets can be stored for clinical applications.

Study Design And Methods: Twenty three subjects were recruited.

Pathogen reduction with amotosalen/UVA reduces platelet refractoriness in a dog platelet transfusion model.

Background And Objectives: Pathogen reduction of donor platelets with amotosalen/UVA has been shown to effectively inactivate pathogens and also contaminating white blood cells (WBCs). We wanted to determine whether WBC inactivation could also decrease alloimmune refractoriness to donor platelets.

Materials And Methods: Platelets were prepared from a donor dog's whole blood, and the platelets were either transfused without modification [standard (STD) platelets] or treated with amotosalen/UVA under conditions modelling the amotosalen/UVA Blood System for human platelets (APR) using either 4 or 3 J/cm of UVA exposure.

Platelets stored in whole blood at 4°C: in vivo posttransfusion platelet recoveries and survivals and in vitro hemostatic function.

Background: Ordinarily, whole blood (WB) is separated into components before storage. We assessed the posttransfusion viability and function of platelets (PLTs) if they were stored within WB at 4°C.

Study Design And Methods: Whole blood was obtained from 30 normal subjects and stored at 4°C without agitation for 12 days and for 10, 15, or 22 days with agitation.

In vivo viability of extended 4°C-stored autologous apheresis platelets.

Background: The current 5-day storage time of room temperature (22°C)-stored platelets (RSPs) severely limits platelet (PLT) availability. Extended cold (4°C)-stored PLTs (CSPs) are currently being investigated for actively bleeding patients. However, we currently do not know how to best store PLTs in the cold for extended periods of time.

Leukofiltration plus pathogen reduction prevents alloimmune platelet refractoriness in a dog transfusion model.

Human lymphocyte antigen alloimmunization to filter leukoreduced (F-LR) platelets occurs in about 18% of immunosuppressed thrombocytopenic hematology/oncology patients and represents a significant challenge for effective chemotherapy. In a dog platelet transfusion model, we have evaluated other methods of preventing alloimmune platelet refractoriness and demonstrated that successful methods in our dog model are transferable to man. In the present study, donor/recipient pairs were dog lymphocyte antigen DR-B incompatible (88% of the pairs), and recipient dogs received up to 8 weekly treated transfusions from a single donor (a highly immunogenic stimulus), or until platelet refractoriness.

Ultraviolet B irradiation in the prevention of alloimmunization in a dog platelet transfusion model.

Background: Alloimmune platelet (PLT) refractoriness remains a significant problem for chronically transfused patients with thrombocytopenia.

Study Design And Methods: In a dog PLT transfusion model, we evaluated ultraviolet B irradiation (UV-B) of donor PLTs-either alone or in combination with centrifuge leukoreduction (C-LR) or filtration leukoreduction (F-LR)-to prevent refractoriness to donor PLTs and to induce tolerance to standard (STD) PLTs from the same donor or to tertiary donors.

Results: Recipient acceptance rates for C-LR donor PLT transfusions were 14%, F-LR were 33%, and UV-B irradiated were 45% with no significant differences among the treatments given to the donor's PLTs.

Further studies to evaluate methods of leucoreduction to prevent alloimmune platelet refractoriness and induce tolerance in a dog platelet transfusion model.

Objectives: Three leucoreduction filters were evaluated - when used alone or combined with centrifuge leucoreduction (C-LR) - to prevent alloimmune platelet refractoriness in a dog platelet transfusion model.

Materials And Methods: Donor platelet-rich plasma (PRP) or buffy coat (BC) platelets were either filter leucoreduced (F-LR) or F-LR/C-LR, (51) Cr radiolabelled and transfused. Weekly transfusions were given for up to 8 weeks or until platelet refractoriness.

Review of in vivo studies of dimethyl sulfoxide cryopreserved platelets.

A literature review was conducted to assess the efficacy and safety of dimethyl sulfoxide (DMSO) cryopreserved platelets for potential military use. In vivo DMSO cryopreserved platelet studies published between 1972 and June of 2013 were reviewed. Assessed were the methods of cryopreservation, posttransfusion platelet responses, prevention or control of bleeding, and adverse events.