Clinical and Interpretive

A reticulocyte count is useful for assessing erythropoietic bone marrow activity in anemia and other hematologic conditions. Reticulocytes are immature erythrocytes (RBC) that have been released into the peripheral blood from the bone marrow after extrusion of their nucleus. The reticulocyte contains residual polyribosomes used in the formation of hemoglobin in the developing erythrocyte. The reticulocyte count is a measure of the number of RBCs delivered by the bone marrow. It is elevated with active erythropoiesis such as regeneration, and is decreased in hypoplastic or deficiency conditions such as vitamin B12 deficiency.

Reticulocyte counts must be carefully correlated with other clinical and laboratory findings. Clotted specimens yield unreliable results and are unacceptable for analysis.