Optical versus impedance lamellar body counts on the Sysmex XT‐2000 automated hematology analyzer (834.13)

Abstract

Introduction: Respiratory distress syndrome, the ninth leading cause of newborn mortality in the US, is caused by fetal lung immaturity due to pulmonary surfactant deficiency. Lamellar body counts (LBC) are often employed for fetal lung maturity assessment. The Sysmex XT‐2000 hematology analyzer measures LBC in amniotic fluid using either impedance or optical platelet counts. The objective of this study was to compare impedance versus optical LBCs.Methods: LBC tests were performed on 18 residual frozen amniotic fluid specimens on a Sysmex XT‐2000 analyzer in an Intermountain Healthcare laboratory, following manufacturer’s instructions for impedance and optical platelet counts.Results: Results were highly correlated (r2=0.99). Mean impedance and optical LBC values were 60.6 and 62.1 x103/uL, respectively (p=0.0079). The mean difference between paired values was ‐2.7% (range ‐7.8% to +3.1%).Conclusions: Impedance and optical LBCs are highly comparable using the Sysmex XT‐2000 analyzer.