Automated reticulocyte counting and immature reticulocyte fraction measurement - Comparison of ABX PENTRA 120 Retic, Sysmex R-2000, flow cytometry, and manual counts

We evaluated reticulocyte counting and measurement of immature reticulocyte fraction (IRF) with the ABX PENTRA 120 Retic blood analyzer on 300 blood s amples. Reticulocyte counts were compared with those obtained by visual cou nting of 2,000 RBCs, by the TOA (Kobe, Japan) Sysmex R-2000 and a flow cyto metry method. The parameters analyzed were the percentages of reticulocytes on all analyzers and the IRF with different modalities. The Retic Count ki t (Becton Dickinson, San Jose, CA) was used with the Coulter (Hialech, FL) XL, and a mean channel of fluorescence (MCF) was calculated to fit the reti culocyte maturation. Reticulocyte counting with the ABX (Montpellier, Franc e) PENTRA 120 Retic showed excellent precision and linearity with no signif icant carryover: Reticulocyte counts were stable after blood storage for 72 hours at 4 degrees C but not at room temperature (RT). IRF parameters valu es were stable for only 8 hours at 4degrees C and 6 hours at RI: Comparison s of the methods showed good intraclass correlation for reticulocyte percen tages between ABX PENTRA 120 Retic and Sysmex R-2000, ABX PENTRA 120 Retic and flow cytometry Sysmex R-2000 and flow cytometry, and ABX PENTRA 120 Ret ic and manual counting. IRF values were correlated between fluorescence rat es and RNA content, but in each case low RI valueswere found showing that S ysmex and ABX IRF values were not concordant. Wc obtained a significant cor relation between mean fluorescence index and the MCF measured by flow cytom etry but the 2 methods were not concordant using the RI. The ABX PENTRA 120 Retic is a good instrument for analyzing reticulocyte count and percentage and allows a good analysis of IRF with several modalities.