Turku University Central Hospital
Turku PET Centre / Pharmacity

Presenter Of 1 Presentation

Biomarkers and Bioinformatics Poster Presentation

P0093 - Increased serum GFAP associates with microstructural white matter damage in multiple sclerosis (ID 1066)

Speakers
Presentation Number
P0093
Presentation Topic
Biomarkers and Bioinformatics

Abstract

Background

Astrocytes and microglial cells are now recognized as active players in contributing to the diffuse neuroaxonal damage associated with disease progression of multiple sclerosis (MS). The serum level of glial fibrillary acidic protein (GFAP), a biomarker for astrocytic activation, is increased in MS and associated with the disease progression and disability. Similarly, diffusion tensor imaging (DTI) parameters for microstructural changes in brain, including demyelination and axonal loss, associate with disability. The association between brain DTI parameters and serum GFAP has not been previously explored in MS.

Objectives

To get insights into DTI-measurable pathological correlates of elevated serum GFAP in the normal appearing white matter (NAWM) of MS.

Methods

A total of 62 MS patients with mean age of 49.4 years were included in the study. Study patients underwent DTI-MRI and blood sampling for GFAP determination by single molecule array (Simoa). MS patients were subdivided to GFAP(high) and GFAP(low) groups based on the median value of GFAP (97.7 pg/ml). Mean fractional anisotropy (FA) and mean (MD), axial (AD) and radial (RD) diffusivities were calculated within the NAWM and six segmented NAWM regions. The associations between the DTI parameters and GFAP levels were analyzed within the GFAP(high) and GFAP(low) subgroups using Spearman correlation analysis and multiple regression model with sex and disease modifying treatment (no, 1st line or 2nd line) as adjustments performed with the R statistical software (version 4.0.0).

Results

Elevated serum GFAP levels correlated significantly with decreased FA values within the entire, frontal, temporal and cingulate NAWM (R=-0.39, p=0.03; R=-0.42, p=0.02; R=-0.37; p=0.04 and R=-0.38, p=0.03) and increased MD and RD within the frontal NAWM (R=0.36, p=0.046 for both) in the GFAP(high) subgroup. Associations between higher GFAP and lower FA in frontal and cingulate NAWM were sustained in the multiple regression model corrected for confounding variables (standardized regression coefficient r = -0.29, p = 0.045 and r = -0.33, p = 0.025).

Conclusions

Our results give evidence that increased serum GFAP levels are associated with DTI-measurable micro-damage in the NAWM in MS. Our work supports the use of serum GFAP as a biomarker for MS pathology-related astrocytopathy and related diffuse white matter damage.

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