Alterations of two parameters of cellular immunity in the aged men.

There were two parameters of cellular immunity in 46 old and 34 adult (control) individuals investigated. These reactions were delayed type hypersensitivity of the skin and the in vitro leukocyte migration inhibition test. PPD was used as antigen for both reactions. According to our investigations there was no correlation between them neither in the aged nor in the control group. But the statistical analysis of data revealed a significant difference between skin responses of aged and control groups. In spite of this we consider cellular immunity unaltered in old men, because there was no difference in migration inhibition between aged and adult men and according to our earlier experiments in guinea pigs this test is much more reliable than skin response.