Peripheral inflammatory markers relate to central inflammation and survival in syndromes associated with frontotemporal lobar degeneration

Abstract

Neuroinflammation is an important pathogenic mechanism in many neurodegenerative diseases, including those caused by frontotemporal lobar degeneration (FTLD). There is a pressing need for scalable and mechanistically relevant blood markers of inflammation to facilitate drug development and experimental medicine. We assessed inflammatory profiles of serum cytokines from 214 patients with FTLD-associated syndromes (behavioural and language variants of frontotemporal dementia, progressive supranuclear palsy, corticobasal syndrome). We tested the association with brain microglial activation (by positron emission tomography) and survival. A pro-inflammatory profile across the FTLD spectrum (including TNF-α, TNF-R1, M-CSF, IL-17A, IL-12, IP-10 and IL-6) differentiated patients (all syndromes) from controls. A higher pro-inflammatory profile scores was associated with higher microglial activation in frontal and brainstem regions, and with lower survival. Blood-based markers of inflammation could increase the scalability and access to neuroinflammatory assessment of people with dementia, to facilitate clinical trials and experimental medicine studies.