Bioplex analysis of plasma cytokines in Alzheimer's disease and mild cognitive impairment

Inflammatory mechanisms within the central nervous system contribute to cognitive impairment via cytokine-mediated interactions between neurons and glial cells. Sixty-nine subjects were consecutively recruited from October 2005 to February 2007. Fifteen individuals were excluded from the study and we ultimately enrolled 19 not cognitively impaired subjects, 25 mild cognitive impairment patients, and 10 Alzheimer's disease patients. To examine the inflammatory markers of mild cognitive impairment and Alzheimer's disease, we measured the plasma concentrations of 23 cytokines using a bioplex assay. The results showed that monokine induced by γ interferon was higher in mild cognitive impairment and in Alzheimer's disease patients compared with the not cognitively impaired group; the results also showed that the macrophage migration inhibitory factor was higher in Alzheimer's disease patients than in not cognitively impaired subjects, as well as those of the mild cognitive impairment group.