SERUM TRANSFERRIN AND FERRITIN IN PUBERTAL BOYS - RELATIONS TO BODY GROWTH, PUBERTAL STAGE, ERYTHROPOIESIS, AND IRON-DEFICIENCY

We studied serum transferrin and ferritin concentrations in relation t o individual body growth, stage of puberty, blood hemoglobin, and red blood cell iron (RBCI) in 60 prepubertal or early pubertal boys at 3-m o intervals for 18 mo. One-third of the boys had increased serum trans ferrin concentrations and almost all had decreased ferritin concentrat ions during the followup. No change in mean transferrin was observed b ut the individual 18-mo increments in transferrin correlated positivel y with the increments in hemoglobin (r = 0.55, P < 0.001) and in estim ated RBCI (r = 0.31, P = 0.02). Serum transferrin remained stable at d ifferent genital stages, but ferritin was lower in the pubertal than i n the prepubertal boys. Transferrin concentrations at 18 mo correlated positively with the preceding weight velocities. The rise in transfer rin did not lead to an increase in iron-deficiency anemia. In contrast , transferrin rose in boys whose hemoglobin increased. In pubertal boy s with relatively ample iron status, serum transferrin may be an indic ator of increased availability of iron for erythropoiesis. The declini ng ferritin concentration indicates that part of the extra iron is mob ilized through redistribution from stores to red blood cell mass and i s generally associated with greatly increasing absorption. Thus, the p ubertal changes in transferrin and ferritin are not necessarily indica tions of iron deficiency.