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 (slL-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<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<0.005). These aberrant immunological phenomena were more frequent among the elderly of group A, compared to group B (p<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.