Sysmex SE-000: Evaluation on the Morphologic Flags and Determination of the Review Criteria

Chae, Seok Lae; Park, Jang Soon; Kim, Dae Chul; Kim, Sung Won; Cha, Young Joo

Abstract

BACKGROUND: We evaluated the performance of leukocyte differential counting and clinical usefulness of the morphologic flags of the SE-000, and set optimal criteria for selecting and reviewing the specimens with increased abnormal cells.
METHODS
From the results of SE-000 and manual leukocyte differential counting in 100 healthy control and 520 patient specimens we evaluated the correlations on the leukocyte fractions as well as the frequency, sensitivity and false positivity of the flags. After determination of the review criteria we calculated total review rate from the 3,403 consecutive CBC specimens.
RESULTS
In both control and patient groups the correlation between two methods was high with the exception of monocytes and basophils. Regarding the morphologic flags, Blast was sensitive (86.9%) however could not detect mature looking lymphoblasts. Immature granulocyte showed high sensitivity (93.7%). Left shift showed the highest frequency (34.6%) and false positive rate (82.8%). Atypical lymphocytes and NRBC showed relatively low sensitivity (63.6%, and 50.5%, respectively). We determined to review the slide when 1) All morphologic flags except Left shift are marked, 2) WBC <3,000/microliter or >20,000/microliter, Hb <8.0 g/dL or 18.0 g/dL, Platelet <100,000/microliter or >600,000/microliter, 3) Severe deviation of leukocyte fractions or 4) Specially requested by physician. As a result, total review rate was 25.0% while 14 abnormal cases with no flags could be additionally detected.
CONCLUSIONS
A new review criteria determined from the results of CBC and leukocyte differential together with morphologic flags could reduce the review rate without skipping the abnormal cases.