Which clinical significance has automatic detection of very low levels of nucleated red blood cells in the peripheral blood?

The direct evaluation through light microscopy (LM) of May-Grünwald-Giemsa (MGG) stained blood smears is still considered the “gold standard” for laboratory identification and count of nucleated red blood cells (NRBC) in peripheral blood (PB). However, the LM procedure is affected with high imprecision and low sensitivity (1). The Sysmex XN-9000 (Sysmex Co., Kobe, Japan) automated hematological analyzer is a modern system able to carry out NRBC count with excellent performance in PB samples, even at very low concentrations (NRBC <2%) (2)