Clinical utility of reticulocyte parameters.

The reticulocyte count reflects the erythropoietic activity of bone marrow and is thus useful in both diagnosing anemias and monitoring bone marrow response to therapy. Automated flow-cytometric analysis has led to a significant advance in reticulocyte counting, by simultaneously providing additional parameters and indices such as the reticulocyte immature reticulocyte fraction (IRF), the reticulocyte volume, and the hemoglobin content and concentration. IRF has been proposed as an early marker of engraftment. Reticulocyte hemoglobin content is useful in assessing the functional iron available for erythropoiesis, and reticulocyte volume is a useful indicator when monitoring the therapeutic response of anemias.