F cells in the adult: normal values and levels in individuals with hereditary and acquired elevations of Hb F

Abstract

Specific antibodies to human fetal hemoglobin were prepared and, after conjugation with a fluorescent dye, were used to determine the distribution of Hb F containing cells in blood smears from normal adults and individuals with hereditary and acquired conditions associated with abnormal levels of Hb F. The mean proportion of F cells in normal persons was 2.7%±1.4%, with a range of 0.5%-7.0%. Proportions of F cells were increased in persons with several acquired and inherited disorders that are associated with an increased percentage of Hb F in hemolysates. A strong linear correlation between the amount of Hb F and proportion of F cells was observed. This technique may prove useful in studies of a variety of disorders associated with Hb F elevations and also in investigations of the mechanisms controlling the transition from fetal to adult hemoglobin during the course of human development.