Soluble interleukin-2 receptors and autoantibodies in the serum of healthy elderly individuals.

Recently, we reported an increased incidence of various autoantibodies in a healthy elderly population (Group A, 64 subjects). Presently we examined whether there is variability in the expression of the age-associated immunological aberrations between different geriatric populations by extending our observations in another healthy elderly population (Group B, 119 subjects). We also determined the serum levels of soluble IL-2 receptors (sIL-2R) attempting to define the activation status of the immune system during senescence. Compared to non-elderly controls, healthy elderly individuals exhibited a significantly higher incidence of autoantibodies as well as significantly higher levels of sIL-2R in serum (p less than 0.001), the latter possibly suggesting the occurrence of lymphocytic activation during the ageing process. The overall prevalence of autoantibodies was statistically associated with the presence of raised sIL-2R levels in serum (p less than 0.005). These aberrant immunological phenomena were more frequent among the elderly of group A, compared to group B (p less than 0.005). In contrast to the uniform expression of various autoantibodies previously observed in group A, the autoantibody profile of group B consisted mainly of rheumatoid factor and antibodies to single-stranded DNA. Finally, no association could be demonstrated between the presence of autoantibodies and HLA antigens in 42 elderly studied.