Effect of anticoagulant and ABO incompatibility on recovery of transfused human platelets.

By RICHARD H. ASTER P LATELET-RICH PLASMA and platelet concentrates are frequently effective in the treatment of hemorrhage secondary to thrombocytopenia.16 The recovery of transfused platelets in the recipients is often low, however, the average ranging from 20-33 per cent in several series.3’5”1 Previous work in this laboratory has shown that a citrate anticoagulant which buffers platelet-rich plasma ( PRP) at pH 6.5 improves the viability of concentrated platelets by facilitating their resuspension without clumping.7 The same study suggested that EDTA, a substance commonly used for platelet transfusions, was toxic for these cells. This work implied that acid citrate was a superior anticoagulant for platelet transfusion therapy, but special manipulations were required to label the platelets with Cr51. In the present study, the effects of different anticoagulant solutions on platelet viability were investigated, utilizing technics comparable to those employed under clinical conditions. Although A and B blood group antigens have been shown to exist on the platelet membrane,84#{176} their importance for platelet transfusion therapy has not been clarified. It has been suggested that the recovery of group A or B platelets transfused to group 0 recipients is equal to that of group 0 donors.#{176} Other workers found a “slight, but consistently lower” recovery of “incompatible” platelets.11 In part, difficulty in assessing the role of ABO antigens in platelet transfusions may have arisen from the relatively low maximum platelet recovery achieved in most studies. The availability of a Cr51-labeling technic that gives a high recovery of platelets7 permits differences in the recovery of incompatible platelets to be more readily apparent. The use of normal subjects as platelet recipients eliminated variables such as hemorrhage and isoimmunization which might obscure the effect of ABO incompatibilty in ill, thrombocytopenic subjects.