Nucleated Red Blood Cells Percent Unit Converter

Nucleated red blood cells (NRBCs) are immature red blood cells that still contain a nucleus. NRBC% measures the percentage of these cells relative to white blood cells in your blood.

During normal red blood cell development in the bone marrow, cells expel their nucleus before being released into the bloodstream. In healthy adults and older children, NRBCs should not be present in circulating blood.

The presence of NRBCs in adult blood indicates that the bone marrow is under significant stress or that there is disruption to normal blood cell production. Newborns normally have some circulating NRBCs, which disappear within the first few weeks of life.

NRBCs originate in the bone marrow as normal precursors during red blood cell production (erythropoiesis). They are normally retained in the marrow until they mature and lose their nucleus before entering the bloodstream.