Effects of CPT anticoagulant on properties of hyperchromic erythrocytes detected by the H*3-Bayer hematologic analyzer

The authors compare the anticoagulant mixture CPT (citrate, pyridoal phosphate and Tris) with the anticoagulant K ³-EDTA in routine automated hematology, measuring the chromatic and volume changes in erythrocytes at 1, 2 and 24 hours after collection. Twenty samples from healthy volunteers were analyzed with the Coulter Counter JT2 and with the H*3 Bayer. There were no statistically significant differences in hemoglobin, in leucocyte and platelet values at 1, 2 and 24 hours after collection, between the two instruments and the two anticoagulants. There were significant differences in mean corpuscular hemoglobin, in mean platelet volume, in anisocytosis index, in platelet crit and in the number of hyperchromic erythrocytes and macrocytes when CPT was used with H*3 Bayer at 1 and 2 hours after collection. At 24 hours hemochromocytometric examination showed that mean corpuscular hemoglobin concentration values stabilized, as did the cytogram regarding hyperchromic erythrocytes. These preliminary results suggest that the pyridoxal phosphate in the CPT not only preserves and stabilizes platelet membrane, but that of erythrocytes too. This stabilization of the erythrocyte membrane makes it possible to use the cytogram to detect spherocytosis by examining it 24 hours after collection.