Enumeration of nucleated red blood cells with the ADVIA 2120 Hematology System: an International Multicenter Clinical Trial.

The accurate, reproducible, and timely reporting of nucleated red blood cells (NRBC) is an important function of the clinical hematology laboratory. We used 960 samples from 5 worldwide sites to evaluate a new NRBC enumeration method for the ADVIA 2120 Hematology System. The method showed excellent correlation with microscopy (r = 0.93). Sensitivity and specificity for the presence of NRBC for all samples analyzed was 77.3% and 74.6%, respectively. Almost all false negative samples were at NRBC counts <or=10/100 white blood cells (WBC). All false negative samples and the vast majority of the false positive specimens would be identified in clinical practice by routine slide review of flagged results, using existing review criteria. The coefficient of variation of the method was <10% for NRBC counts >10/100 WBC. The NRBC method automatically corrects WBC counts and differential results for the presence of NRBC; the uncorrected counts are available to the user on the run screen. This method allows the enumeration of NRBC with the ADVIA 2120 Hematology System in CBC/DIFF sample mode without need for additional hardware, sample preparation, or reagents.