Scoring System for Detecting Spurious Hemolysis in Anticoagulated Blood Specimens

Abstract

Background: The identification of in vitro hemolysis (IVH) using a hematology analyzer is challenging because centrifugation of the specimens cannot be performed for cell counts. In the present study, we aimed to develop a scoring system to help identify the presence of hemolysis in anticoagulated blood specimens. Methods: Thirty-seven potassium EDTA anticoagulated blood specimens were obtained, and each specimen was divided into 3 aliquots (A, B, and C). Aliquots B and C were mechanically hemolyzed by aspirating 2 and 5 times, respectively, using a 27-gauge needle and then tested; aliquot A was analyzed immediately without any hemolysis. After the cells were counted, aliquots B and C were centrifuged and the supernatants were tested for the hemolytic index and lactate dehydrogenase levels. Results: The 4 hematologic parameters were selected and scored from 0 to 3 as follows:<34.0, 34.0-36.2, 36.3-38.4, and ≥38.5 for mean cell hemoglobin concentration (MCHC, g/dL); <0.02, 0.02, 0.03, and ≥0.04 for red blood cell ghosts (1012/L); <0.13, 0.13-0.38, 0.39-1.30, and ≥1.31 for difference value (g/dL) of measured hemoglobin and calculated hemoglobin; and <0.26, 0.26-0.95, 0.96-3.34, and ≥3.35 for difference value (g/dL) of MCHC and cell hemoglobin concentration mean. The hemolysis score was calculated by adding all the scores from the 4 parameters. At the cutoff hemolysis score of 3, the IVH of aliquots B and C were detected as 64.9% and 91.9%, respectively. Conclusions: The scoring system might provide effective screening for detecting spurious IVH.