Review: systemic inflammation and Alzheimer's disease.

There is a great deal of evidence suggesting an important role for systemic inflammation in the pathogenesis of Alzheimer's disease. The role of systemic inflammation, and indeed inflammation in general, is still largely considered to be as a contributor to the disease process rather than of aetiological importance although there is emerging evidence to suggest that its role may predate the deposition of amyloid. Therapies aimed at reducing inflammation in individuals with mild cognitive impairment and Alzheimer's disease have been disappointing and have largely focused on the need to ameliorate central inflammation with little attention to the importance of dampening down systemic inflammation. Novel approaches in this area require a greater understanding of the effects of systemic inflammation on the development and progression of Alzheimer's disease and of the communicating pathways between the systemic and central innate immune systems.