Evaluation of two-dimensional cytometric lamellar body counts on the ADVIA® 120 hematology system for estimation of fetal lung maturation

Background: We sought to determine if the ADVIA® 120 hematology system (Bayer HealthCare LLC, Diagnostics Division, Tarrytown, NY), which employs a unique two-dimensional cytometric analysis approach for platelet (PLT) counting, might also be useful for estimation of LB lamellar body counts in amniotic fluid. Methods: ADVIA® 120 LB counts were performed on 217 amniotic fluid specimens, 88 of which were obtained within 72 h of infant delivery. The ADVIA® 120 LB count (ADVIA LB count) results were compared with results from other FLM tests, including the TDx-FLM II (FLM II) test (Abbott Diagnostics, Abbott Park, IL) and the A 650 estimate of lamellar body density using the refractive-index-matched anomalous diffraction (RIMAD) technique. Results: Use of an ADVIA LB count referent value of ≥35,400/μl to indicate maturity, yielded sensitivity, specificity, PV RDS and PV maturity of 100%, 67.6%, 36.8% and 100%, respectively, in our study population (prevalence of RDS=15.9%). The clinical performance of the ADVIA LB count assay was compared to that of the FLM II and RIMAD assays by predictive value and receiver operating characteristic (ROC) curve analysis. Conclusions: These data suggest that the ADVIA® 120-derived LB counts on amniotic fluid can be useful in predicting fetal lung maturity.