HUMAN RETICULOCYTE MATURATION AND ITS RELEVANCE TO ERYTHROPOIETIC STRESS

Abstract

A comparative study of circulating human reticulocytes by phase-contrast microscopic observation and NMB [new methylene blue] staining revealed 2 different reticulocyte forms which could be clearly distinguished by their distinctive morphologic appearance. These were a multilobular motile form and a cup-shaped nonmotile form. Sequential studies of different populations in circulation of newborns showed that the multilobular form was the youngest and the cup-shaped form the more mature reticulocyte. The multilobular form was found in circulation only under conditions of erythropoietic stress and could not be detected in circulation of hematologically normal individuals. Presence of these characteristic forms in peripheral blood can be used as a reliable indicator of transient or persistent erythropoietic stress.