[Difference in measurements of erythrocyte sedimentation rate obtained using two devices of the same model in a patient with marked leukocytosis].

The erythrocyte sedimentation rate (ESR) has been used as an index for inflammatory conditions, such as infectious diseases, autoimmune diseases, and malignancies. The ESR values of a 37-year-old male with marked leukocytosis due to chronic myeloid leukemia showed remarkable differences between two devices of the same model (Ves-Matic 30, DIESSE Diagnostica Senese). From the appearance of the tested tube after the ESR measurement, the values obtained using one device might have been falsely low, whereas the values obtained using the other device were likely to have been accurate. The difference of the ESR values between the two devices might have occurred by the false detection of transmitted light during the transition from the erythrocyte layer to the leukocyte layer. These findings suggest that in cases with marked leukocytosis the accuracy of ESR should be confirmed with the appearance of the test tube.