Evaluation of reticulocyte count with Cell-Dyn 3500(R): Comparison with a flow cytometry technique

Cell-Dyn 3500(R) automate (Abbott) provides reticulocyte count using a recent software, after ribosomal RNA colouring with methylene blue reagent. The aim of this study was to evaluate results from Cell-Dyn 3500(R), and to compare them with the routine laboratory technique by flow cytometry (FacScan(R), Becton-Dickinson). Cell-Dyn 3500(R) analytical parameters (inter- and intra assay precision, sample-to-sample contamination) were good and in accord to manufacturer's specifications. Reticulocyte values from blood samples kept at 4 degrees C during 3 days were unchanged. Usual values in 145 normal patients were found between 71,3 and 78,3 G/l with Cell-Dyn 3500(R), between 119,3 and 130,2 G/l with FacScan(R). Both techniques were compared in 87 patients with various anemias: Cell-Dyn 3500(R) showed more frequently high reticulocyte values in regenerative anemias (hemorrhagic), but was less performant for classification of aregenerative anemias. Reticulocyte count with Cell-Dyn 3500(R) is a semi automatic, easy to perform and swift technique, using no toxic reagent but unitary test tubes kept at room temperature. The test cost is however high, and Cell-Dyn 3500(R) cannot be used during the analysis.