Age-related changes in surface antigens on peripheral lymphocytes of healthy children

The age-related changes in proportion of various subsets within lymphocytes were investigated in cord blood and peripheral blood from healthy children and adults. The percentages of T and B cells did not show age-related changes, whereas natural killer (NK) cells increased significantly with age. Within lymphocytes or the CD3⁺ T cell population the proportion of CD45RA(bright+) lymphocytes decreased and that of CD45RO⁺ cells increased, while that of CD45RA(dim+) cells showed no age-related change. Within lymphocytes, the percentage of CD45RA(bright+) CD4⁺ cells decreased, together with a decline of that of CD4⁺ cells. The proportions of CD45RA(bright+) CD8⁺ cells and S6F1(bright+) CD8⁺ cells increased with age, and the age-dependent increase of the proportion of CD8⁺ cells seems to be mainly attributable to the increases in these subsets. The CD45RA(dim+) CD4⁺ and CD45RA(dim+) CD8⁺ cells co-expressing CD45RO at a low level nevertheless showed no age-related changes. In γδ T cells, both δTCS1⁺ and δCS1^- T cells increased with age, but the δTCS1^- γδ T cells increased more than the δTCS1⁺ subset. Among lymphocytes, the percentages of CD20⁺, CD21⁺ and CD22⁺ cells remained similar, with no age-related changes, but the proportion of CD5⁺ cells within lymphocytes or B cells decreased. The proportions of CD16⁺ NK cells among lymphocytes increased with age, and this change was attributable to the increase of CD56⁺ cells.