Proinflammatory cytokines in sera of elderly patients with dementia: levels in vascular injury are higher than those of mild-moderate Alzheimer's disease patients.

Cognitive functions display a progressive impairment with ageing, and this is thought to be due to the accumulation of neuronal loss or acute and/or repeated microvascular accidents. Chronic damage to the brain cortex lead to decreasing ability of elderly subjects to cope with daily events and ultimately result in loss of self-sufficiency. Since proinflammatory cytokines have been implicated both in cerebrovascular injury due to atherosclerosis and in Alzheimer's disease (AD), we investigated 70 elderly subjects with neurocognitive and functional impairment. Diagnosis was established in 54, the others were included in the "mixed" group. Sera were collected and stored at -70 degrees C until measurement of IL-1beta and TNF-alpha, performed by commercial ELISA kits. Data obtained were analysed with respect to other socio-demographic, psychoneurological and clinical variables. The results show that serum TNF-alpha was lower in mild-moderate AD compared to severe AD and dementias due to vascular disease, as well as the TNF-alpha/IL-1beta ratio. Both cytokines showed a significant relationship with age. Our study suggests that proinflammatory cytokines serum profiles seem to discriminate between mild-moderate AD and vascular or mixed forms of dementia. Furthermore, it offers new evidence of a strong implication of inflammatory mechanisms in atherosclerosis, more than in less severe AD.