Detection and classification of acute leukemia by the Coulter STKS hematology analyzer

This study evaluated the ability of the Coulter STKS Hematology Analyzer (Coulter, Hialeah, FL) to detect and classify acute leukemias involving the peripheral blood. One hundred ten acute leukemias cases with circulating blasts were studied: 72 acute myeloid leukemias (AML) and 38 acute lymphoblastic leukemias (ALL). The leukemias were divided into 'high WBC count (>11.0 x 10⁹/L)' (28 AML, 22 ALL) and 'normal/low WBC count (≤11.0 x 10⁹/L)' (44 AML, 16 ALL) categories. Most cases in the high WBC count group elicited the blast suspect flag. The remaining cases of AML and ALL in both the high WBC and normal/low WBC count group were detected by the blast flag, other suspect flags, and/or definitive flags. Only one case of AML-M6 was initially missed using these flag combinations; a subsequent analysis elicited the blast flag. The blast populations in the high WBC count group were localized into characteristic myeloblast or lymphoblast regions of the scatterplot in 82.1% of AML, and 63.6% of ALL cases, respectively. However, the remaining cases had indeterminate or aberrant scatterplot patterns, such that an accurate leukemia classification was not possible. The scatterplot pattern also was not helpful in differentiating AML FAB subclasses. The authors conclude that using a combination of appropriate suspect and definitive flags to trigger checking criteria and microscopic review, the Coulter STKS Hematology Analyzer will be successful in detecting virtually all cases of acute leukemia involving the peripheral blood. Although the scatterplots may give useful information, the patterns obtained are not sufficiently distinctive to aid in classifying acute leukemias.