RESUMO
BACKGROUND: Serum neurofilament light chain (sNfL) and glial fibrillary acidic protein (sGFAP) are promising biomarkers that might be associated with clinical and radiological markers of multiple sclerosis (MS) severity. However, it is not known whether they can accurately identify patients at risk of disability progression in the medium and long term. OBJECTIVES: We wanted to determine the association between sNfL and sGFAP, Expanded Disability Status Scale score changes, and conversion to secondary progressive MS (SPMS) in a cohort of 133 patients with relapsing remitting MS. METHODS: Blood samples were collected at inclusion to measure SNfL and sGFAP by single molecule array and their prognostic value was assessed using a linear mixed model. RESULTS: In this cohort, 37 patients (27.8 % of 133) experienced disability progression and 12 patients (9.0 %) converted to SPMS during the follow-up (mean follow-up duration: 6.4 years). Only sNfL (p = 0.03) was associated with conversion to SPMS, and neither SNfL nor sGFAP was associated with disability progression. CONCLUSION: Serum NfL and GFAP do not seem to accurately predict MS outcome in the long term. More studies are needed to determine how serum biomarkers, associated with other clinical and MRI biomarkers, might be used to improve MS prognostication.