[18F]PBR111 and Microglial Activation in Multiple Sclerosis

Multiple Sclerosis is characterized by brain areas of focal neuroinflammation. Imaging of microglia activation in multiple sclerosis could represent a useful marker of neuroinflammation. A novel PET tracer with high affinity to TSPO, \[18F\]PBR111, is a promising tool for PET imaging of activated microglia. This is a study aimed to characterize \[18F\]PBR111 as an in vivo marker of microglial activation in Multiple Sclerosis. Regional binding of \[18F\]PBR111 will be quantified with PET in the brain of up to 24 patients with multiple sclerosis and up to 24 age- and gender- matched healthy volunteers. A subgroup of patients and healthy volunteers will be scanned twice in consecutive days, to test the reproducibility of the measure. Another subgroup of patients will be re-scanned with \[18F\]PBR111 after 4-6 months. MRI-based measures will be acquired at baseline and, in those patients with later repeat PET scans, also after 4-6 months. Data from this study will inform about the possible implementation of the \[18F\]PBR111 ligand to monitor the neuroinflammatory process, disease progression, and response to treatment in MS patients.