Neuroinflammation and its relationship to changes in brain volume and white matter lesions in multiple sclerosis

Datta, Gourab, Colasanti, Alessandro, Rabiner, Eugenii A, Gunn, Roger N, Malik, Omar, Ciccarelli, Olga, Nicholas, Richard, Van Vlierberghe, Eline, Van Hecke, Wim, Searle, Graham, Santos-Ribeiro, Andre and Matthews, Paul M (2017) Neuroinflammation and its relationship to changes in brain volume and white matter lesions in multiple sclerosis. Brain, 140 (11). pp. 2927-2938. ISSN 0006-8950

[img] PDF - Published Version
Restricted to SRO admin only

Download (558kB)

Abstract

Brain magnetic resonance imaging is an important tool in the diagnosis and monitoring of multiple sclerosis patients. However, magnetic resonance imaging alone provides limited information for predicting an individual patient’s disability progression. In part, this is because magnetic resonance imaging lacks sensitivity and specificity for detecting chronic diffuse and multi-focal inflammation mediated by activated microglia/macrophages. The aim of this study was to test for an association between 18 kDa translocator protein brain positron emission tomography signal, which arises largely from microglial activation, and measures of subsequent disease progression in multiple sclerosis patients. Twenty-one patients with multiple sclerosis (seven with secondary progressive disease and 14 with a relapsing remitting disease course) underwent T1- and T2-weighted and magnetization transfer magnetic resonance imaging at baseline and after 1 year. Positron emission tomography scanning with the translocator protein radioligand 11C-PBR28 was performed at baseline. Brain tissue and lesion volumes were segmented from the T1- and T2-weighted magnetic resonance imaging and relative 11C-PBR28 uptake in the normal-appearing white matter was estimated as a distribution volume ratio with respect to a caudate pseudo-reference region. Normal-appearing white matter distribution volume ratio at baseline was correlated with enlarging T2-hyperintense lesion volumes over the subsequent year (ρ = 0.59, P = 0.01). A post hoc analysis showed that this association reflected behaviour in the subgroup of relapsing remitting patients (ρ = 0.74, P = 0.008). By contrast, in the subgroup of secondary progressive patients, microglial activation at baseline was correlated with later progression of brain atrophy (ρ = 0.86, P = 0.04). A regression model including the baseline normal-appearing white matter distribution volume ratio, T2 lesion volume and normal-appearing white matter magnetization transfer ratio for all of the patients combined explained over 90% of the variance in enlarging lesion volume over the subsequent 1 year. Glial activation in white matter assessed by translocator protein PET significantly improves predictions of white matter lesion enlargement in relapsing remitting patients and is associated with greater brain atrophy in secondary progressive disease over a period of short term follow-up.

Item Type: Article
Keywords: multiple sclerosis, microglia, atrophy, translocator protein, positron emission tomography
Schools and Departments: Brighton and Sussex Medical School > Neuroscience
Subjects: R Medicine > RC Internal medicine > RC0321 Neurosciences. Biological psychiatry. Neuropsychiatry
Depositing User: Alexei Fisk
Date Deposited: 26 Oct 2017 10:43
Last Modified: 28 Nov 2017 10:06
URI: http://sro.sussex.ac.uk/id/eprint/70675

View download statistics for this item

📧 Request an update