Tiruneh Adane, Fikir Asrie, Zegeye Getaneh
Automated flow cytometric analysis has led to a significant advance in reticulocyte counting, providing the immature reticulocyte fraction (IRF). IRF is one of the newer parameters of automated hematology analyzers and is a sensitive measure of erythropoiesis. The manual reticulocyte counts enumerate all RNA stained cells and simply puts together immature and mature reticulocytes. It is also laborious and time-consuming. Flow cytometric reticulocyte analysis is more precise and sensitive than the manual count. Besides, the measured fluorescence intensity allows quantification of reticulocyte maturity. IRF gives a basic idea about the marrow erythropoietic activity and its response to drugs and therapy. Moreover, it is simple, quick, cost- effective, reproducible and reliable tool on the automated hematology analyzer. It is also important for the evaluation of aplastic anemia in cases of pancytopenia, as an indicator of postchemotherapy bone marrow recovery in acute leukemia patients, and in guiding stem cell harvest in autologous peripheral blood stem cell transplant. IRF, in combination with the reticulocyte count, might be useful in improving the classification of anemia, monitoring bone marrow recovery, and monitoring anemia therapies. It is necessary to establish an international consensus about the definition and reference range of IRF, to compare results obtained from different hematology analyzers.