Imaging Inflammation in the Huntington Disease Brain

Microglia — the immune cells of the nervous system — are increasingly recognized as important players in neurodegenerative diseases. Numbers of activated microglia are elevated in the brains of people with Huntington disease (HD) (J Neuropathol Exp Neurol 2001; 60:161), and minocycline, which protects against microglia-mediated excitotoxicity, is being evaluated as a potential therapeutic agent for HD. Activated microglia release pro-inflammatory cytokines, such as tumor necrosis factor α and interleukin 1β. They also express peripheral benzodiazepine binding sites, which can be labeled by ¹¹C-(R)-11195, a tracer used in PET. A previous report from this group identified higher binding activity of ¹¹C-(R)-11195 in the brains of symptomatic p…