Age dependence of subpopulations and functions of human peripheral lymphocytes.

The eventual dependency of a series of immune parameters on age has been studied in a material of 288 normal persons, divided into 2 sexes and with 16 persons in each 5-year age interval between 5 and 95 years, using a cryobiological freezing and storage system for lymphocytes with subsequent testing in large series. Lymphocyte transformation responses were studied after stimulation with a series of mitogens and specific antigens (PHA, PWM, PPD, Con A, SA, EC, CA and SK/SD), as well as with allogene cells in mixed lymphocyte culture. Values were found to decrease with increasing age. No age-dependency could be demonstrated for T and B lymphocytes using rosette formation tests. There was no difference between the two sexes. Thus, increasing age does not change the distribution between T and B lymphocytes, but does lead to a decrease in the function of the cell-mediated response.