Safety and efficacy of cryopreserved platelets in bleeding patients with thrombocytopenia.

BACKGROUND: The short dating period of room temperature-stored platelets (PLTs; 5-7 days) limits their availability at far-forward combat facilities and at remote civilian sites in the United States. PLT cryopreservation in 6% DMSO and storage for up to 2 years may improve timely availability for bleeding patients. STUDY DESIGN AND METHODS: A dose escalation trial of DMSO-cryopreserved PLTs (CPPs) compared to standard liquid-stored PLTs (LSPs) was performed in bleeding patients with thrombocytopenia. Within each of four cohorts, six patients received escalating doses of CPP (0.5 unit, 1 unit, and sequential transfusions of 2 and 3 units) and one received a LSP transfusion. Patients were monitored for adverse events (AEs), coagulation markers, PLT responses, and hemostatic efficacy. RESULTS: Patients with a World Health Organization bleeding score of 2 or more received from 0.5 to 3 units of CPP (n = 24) or 1 unit of LSP (n = 4). There were no related thrombotic or other serious AEs experienced. Mild transfusion-related AEs of chills and fever (n = 1), transient increased respiratory rate (n = 1), DMSO-related skin odor (n = 2), and headache (n = 1) were observed after CPP transfusion. Among CPP recipients 14 of 24 (58%) had improved bleeding scores, including three of seven (43%) patients who had intracerebral bleeding. CPP posttransfusion PLT increments were significantly less than those of LSPs; however, days to next transfusion were the same. After transfusion, the CPP recipients had improvements in some variables of thrombin generation tests and thromboelastography. CONCLUSION: Cryopreserved PLT transfusions appear to be safe and effective when given to bleeding patients with thrombocytopenia.

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. Using the Department of Defense's preferred 6% DMSO cryopreservation method with centrifugation to remove the DMSO plasma before freezing at -65°C and no postthaw wash, mean radiolabeled platelet recoveries in 32 normal subjects were 33% ± 10% (52% ± 12% of the same subject's fresh platelet recoveries), and survivals were 7.5 ± 1.2 days (89% ± 15% of fresh platelet survivals). Using a variety of methods to freeze autologous platelets from 178 normal subjects, mean radiolabeled platelet recoveries were consistently 39% ± 9%, and survivals, 7.4 ± 1.4 days. More than 3000 cryopreserved platelet transfusions were given to 1334 patients. There were 19 hematology/oncology patient studies, and, in 9, mean 1-hour corrected count increments were 11 100 ± 3600 (range, 5700-15 800) after cryopreserved autologous platelet transfusions. In 5 studies, bleeding times improved after transfusion; in 3, there was either no improvement or a variable response. In 4 studies, there was immediate cessation of bleeding after transfusion; in 3 studies, patients being supported only with cryopreserved platelets had no bleeding. In 1 cardiopulmonary bypass study, cryopreserved platelets resulted in significantly less bleeding vs standard platelets. In 3 trauma studies, cryopreserved platelets were hemostatically effective. No significant adverse events were reported in any study. In summary, cryopreserved platelets have platelet recoveries that are about half of fresh platelets, but survivals are only minimally reduced. The platelets appear hemostatically effective and have no significant adverse events.