Serum interleukin-2 levels in patients with dementia of the Alzheimer type.

We examined serum interleukin 2 (IL-2) levels in 127 normal subjects and 22 patients with dementia of the Alzheimer type (DAT) using the enzyme-linked immunosorbent assay technique. There was no significant correlation between serum IL-2 levels and age. However, serum IL-2 levels in elderly normal subjects (older than 70 years of age) were significantly lower than in the younger normal subjects (younger than 30 years of age) (p less than 0.05). There were no significant differences in serum IL-2 levels between the patients with DAT and the age-matched normal controls. These results suggest that the changes of serum IL-2 levels in patients with DAT may be natural in the normal aging process.