Abstract
One hour after blood collection, the platelet concentrate was frozen with the same volume of a 10% glycerol solution (10% glycerol, 1% mannitol, 1% glucose and 0.6% NaCl) or a 10% Me2SO in plasma. The cooling rate was controlled at a speed of 1-5°C per min until -65°C and then immersed into liquid nitrogen. Thawed glycerolized or Me2SO added platelet concentrates were infused intravenously after one wash with 100 ml of 0.9% saline solution. To evaluate the effect of thawed deglycerolized or Me2SO platelets, the improve-ment of bleeding tendency by aspirin was observed by the autologous transfusion of pro-cessed platelets into the original donors. Every platelets frozen in a 5% glycerol or a 5% Me2SO improved the bleeding tendency by aspirin. A 5% Me2SO showed stronger cryo-protection for platelets than that of glycerol. The in vivo life spans (T 1/2) and the in vivo recovery rates were better in platelets frozen in 5% Me2SO than in those in 5% glycerol. Electronmicrogram and ADP aggregability of frozen-thawed platelets in a 5% Me2SO in plasma showed better results. No side effects were seen. A total of 598 units of thawed platelets were infused into 61 patients complaining of thrombocytopenia and bleeding (or oozing): 20 with idiopathic thrombocytopenic purpura, 13 with acute myeloid leukemia and others, of whom the platelet counts increased in 47 patients (77.0%) and the bleeding time (oozing) was improved in 39 patients (64%).
