Clinical utility of the new Beckman-Coulter parameter red blood cell size factor in the study of erithropoiesis.

CHr has been used as a diagnostic tool, together with biochemical markers, to distinguish IDA from ACD, and is incorporated to NKF-K/DOQI guidelines for the monitoring of rHuEPO therapy. The measurement of CHr has been restricted to the analysers of a single manufacturer, Siemens. Red blood cell size factor (RSf) is a new parameter provided by Beckman-Coulter which joins together the volume of erythrocytes and the volume of reticulocytes Rsf = square root (MCV x MRV). The aims of the study were to establish the values of RSf in normal population and in different types of anemia to investigate its clinical usefulness in the study of erythropoiesis and its correlation with CHr. Samples from 449 patients (learning group) were run sequentially on both LH 750 (Beckman-Coulter) and Advia 2120 (Siemens) analysers. Good correlation between CHr and RSf was observed, r(2) = 0.85. Receiver operating characteristic curve analysis for RSf and the diagnosis of restricted erythropoiesis. [table: see text] The diagnostic usefulness of RSf was evaluated on a validation group which included 220 consecutive patients with anemia. This study shows a very good level of agreement between RSf and CHr. Both are suitable parameters for the study of erythropoiesis.