Brain inflammation in Alzheimer disease and the therapeutic implications

Immunohistochemical studies suggested the existence of a chronic inflammato ry condition in affected regions of the brain in Alzheimer disease (AD). Si nce inflammation can be damaging to host tissue, it was hypothesized that a ntiinflammatory drugs might inhibit both the onset and the progression of A D. This hypothesis is supported by a number of epidemiological studies sugg esting that the prevalence of AD in persons is reduced by 40 - 50% in perso ns using antiinflammatory drugs. In one small pilot trial in early AD, the nonsteroidal antiinflammatory drug indomethacin appeared to halt the progre ssive memory loss. Immunohistochemical and molecular biological studies on immune system components in AD brain are revealing the complexities of the innate immune reaction. This very complexity may offer points of therapeuti c intervention for new types of antiinflammatory agents. The complement sys tem, microglia and cytokines are key components. This review summarizes the present state of knowledge on the immune system elements found in AD brain .