[Evaluation of reticulocyte count on Cell-Dyn 3500 automate: comparison with a flow cytometry technique]

Cell-Dyn 3500 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, and to compare them with the routine laboratory technique by flow cytometry (FacScan, Becton-Dickinson). Cell-Dyn 3500 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, between 119.3 and 130.2 G/l with FacScan. Both techniques were compared in 87 patients with various anemias: Cell-Dyn 3500 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 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 cannot be used during the analysis.