Background. Flow cytometric analysis of major lymphocyte populations and their subsets reveals age related changes in the human cellular immune system. Subjects and methods. Immunophenotypic markers were evaluated in 136 healthy pediatric subjects divided into groups of newborn infants (cord blood), children aged 1 to 2 years, 2 to 5 years, and 6 to 15 years. Results. The percentage of T cells increased gradually with age and the evolution of the percentage of B and NK cells was found to be variable. The percentage of CD4+ cells remains relatively unchanged from infancy to adolescence, but the percentage of CD8+ T cells was lowest at birth and reached maximal levels in the one to two year-old period. The percentage of naive T cells declined with time, but the percentage of memory T cells increased with age. Similar trends were seen in T-cell receptor αβ- and γδ-bearing T cells. The percentage of CD11b+CD8+ T cells increased gradually from birth and reached maximal levels from 6 to 15 years old. The expression of the activation markers CD25 and HLA-DR on CD4+ T cells increased with age. The percentage of CD16+CD56- NK cells declined with age, but the evolution of the percentage of CD16-CD56+ NK cells was variable. The fraction of B cells that expressed CD5 was high at birth (72.9%) and was highest in one to two year olds (73.1%), then declined steadily over time. The CD23 antigen was expressed on 41.9% of B cells at birth and 68.6% during the first to second year, then declined steadily with age. Conclusion. These data may serve as a reference range for studies of Chinese pediatric subjects.
|頁（從 - 到）||215-220|
|期刊||Pediatric Allergy and Immunology|
|出版狀態||已發佈 - 十一月 1998|
ASJC Scopus subject areas
- Immunology and Allergy
- Pediatrics, Perinatology, and Child Health