Assessment of neuronal and glial serum biomarkers in myelin oligodendrocyte glycoprotein antibody-associated disease: the MULTIMOGAD study.

Background: Serum neurofilament light chain (sNfL) and serum glial fibrillary acidic protein (sGFAP) have emerged as important biomarkers in multiple sclerosis (MS) and aquaporin-4 seropositive neuromyelitis optica spectrum disorder (AQP4-NMOSD). However, their interest in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) remains unclear. Our aim was to characterise sNfL and sGFAP profile and analyse their usefulness in predicting relapses and disability in MOGAD.

Methods: Retrospective study of adult MOGAD patients with serum samples collected at baseline (≤3 months from disease onset) and follow-up (>6 months from baseline sample). sNfL and sGFAP were analysed using Simoa HD-1, and values were compared across time-points. The association between biomarkers and clinical variables and their predictive value for disability and relapses were analysed.

Results: Eighty-nine MOGAD patients were included. Baseline sNfL and sGFAP values were high at baseline and decreased over time (p<0.001, p=0.027, respectively). sNfL and sGFAP values were associated with Expanded Disability Status Scale (EDSS) at attacks (β 0.15 (0.06; 0.25), p=0.002; β 0.14 (0.07; 0.21), p<0.001, respectively) and were lower in optic neuritis presentations (β -0.69 (-1.18; -0.19), p=0.007; β -0.42 (-0.76; -0.08), p=0.016). Biomarker deltas[Δ] (baseline values - second samples values) were associated with ΔEDSS (initial EDSS - final EDSS) (ΔsNfL β 0.52 (0.01; 1.04), p=0.046; ΔsGFAP β 1.07 (0.38; 1.75), p=0.003). Finally, sNfL values independently predicted the risk of relapses (HR 2.06 (1.41; 3.01), p<0.001).

Conclusions: Our results on sNfL and sGFAP suggest initial neuro-axonal and astrocytic damage in MOGAD and the utility of these biomarkers at onset and follow-up in predicting clinical recovery and relapses.