An evaluation of the Technicon H-1 automated hematology analyzer in detecting peripheral blood changes in acute inflammation.

The Technicon H-1 (H-1) is an automated hematology analyzer that provides a complete blood cell count, a six-part differential with absolute counts, and morphologic values with a left-shift flag (LS). To determine the sensitivity of the H-1 in detecting peripheral blood changes in acute inflammation, we first correlated the H-1 LS with band counts on the Hematrak 590 (H590), an automated digital image processor differential system. The H-1 sensitivity to H590 band counts above 11% was 76%, specificity was 82%, and efficiency was 80%. Each semiquantitative LS (1+, 2+, 3+), as well as a new factor, lobularity index, was correlated with the actual H590 band count. There was a definite direct proportional relationship between each semiquantitative LS and the mean band count. However, the wide overlaps of band count ranges corresponding to each semiquantitative flag rendered semiquantitation of limited value. Forty cases with the clinical diagnosis of acute appendicitis were similarly studied preoperatively. Thirty-three cases histologically showed acute inflammation. On the H-1, 79% (sensitivity) had LS flags, 88% had absolute neutrophilia (greater than 8 x 10(9)/L), 82% had relative neutrophilia (greater than 75%), and 91% had leukocytosis (greater than 10.5 x 10(9)/L). In comparison, sensitivities on the H590 were 70% for band counts above 11%, 82% for relative neutrophilia, and 85% for absolute neutrophilia. This study shows that the H-1 is at least as sensitive as the H590 to peripheral blood changes that indicate acute inflammation.