AGE-RELATED-CHANGES IN SURFACE-ANTIGENS ON PERIPHERAL LYMPHOCYTES OF HEALTHY-CHILDREN

The age-related changes in proportion of various subsets within lympho cytes were investigated in cord blood and peripheral blood from health y children and adults. The percentages of T and B cells did not show a ge-related changes, whereas natural killer (NK) cells increased signif icantly with age. Within lymphocytes or the CD3(+) T cell population t he proportion of CD45RA(bright+) lymphocytes decreased and that of CD4 5RO(+) 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(+) cel ls. 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 inc reases in these subsets. The CD45RA(dim+) CD4(+) and CD45RA(dim+) CD8( +) cells co-expressing CD45RO at a low level nevertheless showed no ag e-related changes. In gamma delta T cells, both delta TCS1(+) and delt a TCS1(-) T cells increased with age, but the delta TCS1(-) gamma delt a T cells increased more than the delta TCS1(+) subset. Among lymphocy tes, the percentages of CD20(+), CD21(+) and CD22(+) cells remained si milar, with no age-related changes, but the proportion of CD5(+) cells within lymphocytes or B cells decreased. The proportions of CD16(+) N K cells among lymphocytes increased with age, and this change was attr ibutable to the increase of CD56(+) cells.