Nucleated red blood cells and soluble transferrin receptor in thalassemia syndromes: relationship with global and ineffective erythropoiesis.

BACKGROUND: The technology to recognize nucleated red blood cells (NRBC) automatically has only recently been developed. Modern hematology analyzers allow for rapid and accurate NRBC counts. The goal of our study was to evaluate NRBC counts and the concentrations of serum transferrin receptor (sTfR) in patients affected by different thalassemia syndromes and hereditary spherocytosis. We wished to gain a better understanding of the meaning of the presence of NRBC in peripheral blood and the relationship of the two parameters with effective and ineffective erythropoiesis in the different thalassemia syndromes.
METHODS: NRBC counts in peripheral blood were evaluated in a large group of patients with thalassemia (36 thalassemia major, 55 thalassemia intermedia and 61 Sbeta-thalassemia patients) and compared with data from 29 patients with hereditary spherocytosis; in all the patients the concentration of sTfR was evaluated as an index of global erythropoiesis.
RESULTS: The NRBC count showed a good relationship with ineffective erythropoiesis: highest counts were observed in the thalassemia syndromes characterized by almost completely ineffective erythropoiesis. NRBCs were absent in patients affected by hereditary spherocitosis, a disease characterized by effective erythropoiesis.
CONCLUSIONS: The NRBC count can be useful for better defining ineffective erythropoiesis in patients with thalassemia, and can help optimize transfusion therapy in severe thalassemia syndromes.