Immune senescence: effect of age, sex and health on human blood mononuclear subpopulations.

The respective influence of age, sex and health states on peripheral blood mononuclear subpopulations has been investigated in 194 institutionalized subjects. The "ill group' includes patients with various diseases and the "reference group' was referred to admission criteria for immuno-gerontological disease. A decline of total mature T-cell (OKT3) and helper T-cell (OKT4) proportions with ageing has been found only in the ill group and remains stable in the reference group. This age-dependent decline should represent either a susceptibility for illness or a consequence of higher incidence of illness with ageing. Suppressor-cytotoxic (OKT8), B- and T-activated (OKIa1), null (OKM1), and early E-rosette forming cells do not vary with ageing in both groups. It has been established previously that women have higher values of the percentages of early E-rosette forming cells.