Evaluation of the white blood cell differential given by the new analyser Coulter STKS in both hematological and non-hematological patient groups.

The White Blood Cell differential given by the new analyser Coulter STKS was studied in a group of hospitalized patients originating from non-hematological departments (group 1; n = 290) and a group of patients suffering from an hematological disease (group 2; n = 106) with blood smear abnormalities. A good relationship between the reference method and the STKS results was shown in 200 patients without hematological abnormalities. Both sensitivity and reliability of alarms were evaluated in both groups. In group 1, we noticed respectively: 208 true negative, 40 true positive, 7 false negative, 35 false positive. Six of the seven false negative results were related to the presence of a slight myelemia without hematological significance, one to the presence of small quantity of circulating blasts with a leuconeutropenia. In group 2, all abnormalities seen on the blood smear were detected by the Coulter STKS either by an alarm message (93 cases) or by an increase of the lymphocyte population (9 cases) in some chronic lymphocyte leukemias, or by an important leuconeutropenia (4 cases) in acute treated leukemias. The results of the White Blood Cell differential performed with the Coulter STKS exhibited a good relationship with the reference method for normal bloods and a good reliability for detection of abnormal cells.