[The effect of blood platelet freezing on their antigen activity]

The authors investigated the effect of freezing of platelets after addition of various cryoprotective substances (glycerol, dimethyl sulphoxide and hydroxyethyl starch) on the preservation of some antigenic properties of these blood cells. It was revealed that during freezing of platelets in 5% glycerol and 4% hydroxyethyl starch no change of the specific antigen Kob and of HLA antigens occurred. Freezing in dimethylsulphoxide, however, weakened the activity of some antigens; usually this applied to antigen Kob, in HLA antigens it was rather an exception. From the results ensues, however, that in the transfusion practice it is important to foresee even in transfusions of cryopreserved platelets possible alloimmunization.