Inflammatory markers in Alzheimer's disease and multi-infarct dementia

Inflammation has been involved in the pathogenesis of dementia. The study e valuates the presence and the source of pro- and anti-inflammatory cytokine s in the blood of patients with Alzheimer's disease (AD), multi-infarct dem entia (MID) or in non-demented elderly people (controls). Tumor necrosis fa ctor (TNF)-alpha interleukin (IL)-l beta, IL-6, IL-10, IL-1 receptor antago nist (IL-1Ra) and soluble TNF receptor I (sTNF-RI) plasma concentrations an d release from blood cells stimulated with lipopolysaccharide (LPS, 1 mug/m l) were determined. The results show that TNF-alpha released from blood cel ls is significantly decreased (27%) in all demented patients compared to co ntrols. Circulating TNF-alpha is increased (400%) only in MID patients. In these patients plasma levels of sTNF-RI are increased (53%) and IL-10 from stimulated blood cells decreased (47%) compared to non-demented subjects. T he results show that: (1) peripheral production of TNF-alpha is blunted in demented (both AD and MID) patients compared to non-demented age-matched su bjects; (2) AD patients have a selective disregulation of the peripheral TN F-alpha system; (3) different cytokines are up- or down- regulated in MID p atients showing that in this condition the pro- and anti-inflammatory perip heral cytokine system is more widely affected. (C) 2001 Elsevier Science Ir eland Ltd. All rights reserved.