Do the reticulocyte maturation fractions and bone marrow reticulocyte count further help the classification of anemias?

Background: Reticulocyte count plays a major role in anemic evaluation. The conventional method done by the manual supravital staining cannot subclassify the group of less than 2% of corrected reticulocyte count. The newly-developed flow cytometer provides different maturation fractions by measuring its fluorescent intensity. The reticulocytes are believed to shift to the circulation from the bone marrow earlier in more severe anemia. Therefore, the purpose of this study is to evaluate the role of reticulocyte maturation fractions and bone marrow reticulocyte in anemia classification.

Methods: By using a fully automated counter, the roles of the reticulocyte with maturation and their shifting from bone marrow were evaluated in anemias. Different groups of subjects (243 in total) including aplastic, nutritional, and infiltrative anemias and anemia due to excess destruction and blood loss were studied. Each subject had bone marrow examination for morphologic diagnosis and reticulocyte evaluation.

Results: Both the absolute count and the maturation fractions of reticulocytes showed significant difference among marrow infiltration, aplastic anemia, and hemolytic anemia. Both the absolute reticulocyte count and less mature fractions were lowest in aplastic group. The marrow reticulocyte counts and shift ratio to circulating blood added little benefit in the classification of anemias.

Conclusions: The automated reticulocyte count with maturation fractions helps classify anemias, particularly for those with low reticulocyte count by the manual method.