Influence of ACD and CPD Anticoagulants on White Cell Aggregation

Red blood cells separated from plasma by centrifugation showed consistently greater white blood cell clumping where CPD was the anticoagulant, as compared to ACD. This resulted in an apparently low count of leukocytes in the packed red blood cells. Such was true whether samples were observed at 26 C (room temperature) or at 37 C. With both anticoagulants, aggregation could be significantly reduced by acidification of the plasma to below pH 7.0; while above this pH, clumps remained intact. However, at any pH, clumping was less in ACD.