Changes in hematologic parameters induced by thermal treatment of human blood

Abstract. To investigate the effects of high temperature on hematologic parameters of human blood, we assessed complete blood cell counts, red cell indices, and platelet aggregability in 72 adult blood samples after exposure to varying degrees of temperature. There were no significant differences in erythrocyte counts, hemoglobin concentration, or mean corpuscular hemoglobin (MCH) between pre- and post-treated groups when blood samples were treated at 50 degrees C for 5 min. Under the same conditions, however, mean corpuscular volume (MCV) and hematocrit became significantly higher in the post-treated group (p <0.01). A dramatic increase was observed in the numbers of platelets and eosinophils measured by electronic counter: the mean numbers of platelets and eosinophils in the post-treated group (2,978.2 x 109/L and 5.58 x 10(9)/L) were significantly higher than those for the pre-treated group (246.6 x 10(9)/L and 0.15 x 10(9)/L, p < 0.01). Platelet clumps of varying size were seen in EDTA-anticoagulated blood after exposure to 46 degrees C for 90 sec; however, these clumps were not detected in citrate-, heparinized-, or washed EDTA-anticoagulated blood. Platelet aggregability to various agonists was profoundly decreased after treating the blood at 43 degrees C for 5 min. In summary, this study shows that critical changes of hematologic parameters occur when blood is exposed to 50 degrees C, and that the anticoagulating property of EDTA is altered upon exposure to high temperature.