Elevated interleukin-6 secretion levels by mononuclear cells of Alzheimer's patients.

It has been suggested in recent research that interleukin-1 (IL-1) and interleukin-6 (IL-6) play a role in the pathogenesis of Alzheimer's disease (AD). Production of IL-1, by lipopolysaccharide (LPS)-stimulated monocytes, and IL-6, by phytohaemagglutinin (PHA)-stimulated mononuclear cells, was assessed in patients with AD divided into two groups--mild and moderately severe--according to severity of disease, and elderly controls. No differences in IL-1 production were found among AD patients and controls. However, significant elevation in IL-6 secretion levels was observed in both the mild and moderately severe AD patients. Our results suggest that peripheral IL-6 secretion levels may be responsible for acute-phase proteins observed in the serum of AD patients.