Automated Nucleated Red Blood Cell Counting in the Perinatal Period


Laboratory Hematology 8:179-188
© 2002 Carden Jennings Publishing Co., Ltd.


We investigated the performance of automated nucleated red blood cell (NRBC) identification and enumeration in perinatal and cord blood specimens by Sysmex XE-2100 analyzers, a new generation of cell analyzers that use laserbased optical and fluorescence detection systems. For cord blood specimens the Sysmex XE-2100 automated NRBC count correlated well with both the traditional manual count (R2 = 0.99 for both percentage and absolute counts) and a flow-cytometry-based reference NRBC count (R2 = 0.99 for both percentage and absolute counts). The automated NRBC count was linear over a wide range of counts and showed good reproducibility. In addition, counting was accurate and stable for specimens up to 2 days old stored either at room temperature or under refrigeration. In perinatal specimens, the XE-2100 showed good correlation with the manual count for percentage NRBC counts (R2 = 0.93) and acceptable correlation for absolute NRBC counts (R2 = 0.77). There was good correlation between the XE- 2100 and the reference flow cytometry method for both percentage (R2 = 0.94) and absolute (R2 = 0.86) NRBC counts. The results of our investigation of NRBC counts in normal and abnormal neonatal specimens demonstrate that for evaluating NRBC counts and determining reference ranges for NRBCs in the perinatal period, the postnatal age is a more advantageous parameter than the postconception age (gestational age plus postnatal age). For NRBC counts in the perinatal period, the automated NRBC count should replace the traditional manual NRBC count because the automated count has higher precision and is less timeconsuming and labor-intensive.

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