Chronic activation of peripheral blood macrophages in Alzheimer's disease

Alzheimer's disease (AD) is thought to involve the activation of brain-resi dent macrophages. In order to assess possible changes in peripheral macroph ages of AD patients, we examined peripheral blood for both macrophage activ ation in vitro and accelerated apoptosis. In the majority of cases clinical ly diagnosed for probable AD, both accelerated apoptosis and correlated mac rophage activation were found depending on clinical severity. Additionally, short-term cultures of unstimulated peripheral blood mononuclear cells wer e used to eliminate the accumulation of apoptotic cells by either depletion of activated T-cells or stimulation of macrophages. We conclude that these peripheral phenomena parallell inflammatory-like processes in the brains o f patients with AD and could perhaps be useful in monitoring anti-inflammat ory therapy currently being tested in Alzheimer's dementia.