The Profile of CD71+ Erythroid Cells in Korean Children: A Pilot Study

<b><i>Background:</i></b> CD71+ erythroid cells (CECs) play a complex immunoregulatory role. <b><i>Methods:</i></b> Flow cytometry was used to assess CECs in 84 individuals, from preterm infants to adults, divided into 5 age groups, 12 from infants under 6 months, 16 from young children (6 months-5 years), 24 from children (6-10 years), 22 from adolescents (11-19 years), and 10 from adults (≥20 years). <b><i>Results:</i></b> CECs are universally present at very low frequencies, except in individuals younger than 6 months (<i>P</i> < 0.001). Although preterm infants tended to have a higher median CECs than full-term infants, this difference was not statistically significant. Among individuals over 6 months, CECs showed significant negative correlations with hemoglobin (r = -0.448, <i>P</i> < 0.001) and hematocrit (r = -0.416, <i>P</i> < 0.001), but no such correlations were found in younger infants. <b><i>Conclusions:</i></b> CECs are present across all age groups, with higher levels in early infancy.