Persistent nucleated red blood cells in peripheral blood is a poor prognostic factor in patients undergoing stem cell transplantation.

We compared detection rates and counts of nucleated red blood cell (NRBC) in the peripheral blood of survivors and nonsurvivors (total 44 patients) of stem cell transplantation. The rate of NRBC detection increased to 79.5% after transplantation. After engraftment, the detection rate of NRBC decreased to 17.0% in survivors, but increased to 100% in nonsurvivors. The NRBC count increased after transplantation in both groups. This increase was transient in survivors, but increased after engraftment in nonsurvivors. The mean NRBC count after engraftment was 872 vs. 40.3 for nonsurvivors vs. survivors, respectively. At postengraftment, all patients who were negative for NRBC survived, but 10 of the 15 patients who were positive for NRBC died (66.7%). The survival rates of patients with a NRBC count > 200 x 10(6)/l were significantly lower than those of patients whose counts were < 100 x 10(6)/l. These data indicated that persistent NRBC in peripheral blood is a poor prognostic factor, and suggested that monitoring NRBC after SCT might provide useful clinical information.