Serum neurofilament light chain predicts long-term prognosis in Guillain-Barré syndrome patients

ObjectiveTo study baseline serum neurofilament light chain (sNfL) levels as a prognostic biomarker in Guillain-Barre syndrome (GBS). MethodsWe measured NfL using SiMoA in serum (98 samples) and CSF (24 samples) of GBS patients prospectively included in the International GBS Outcome Study (IGOS) in Spain and compared them with controls (HC). We performed multivariable regression to analyze the association between sNfL levels and functional outcome at one year. ResultsGBS patients had higher NfL levels than HC in serum (55.49pg/mL vs 9.13pg/mL, p<0,0001) and CSF (1308.5pg/mL vs 440.24pg/mL, p=0.034). Patients with preceding diarrhea had higher sNfL than patients with respiratory symptoms or no preceding infection (134.90pg/mL vs 47.86pg/mL vs 38.02pg/mL, p=0.016). sNfL levels correlated with GDS and R-ODS scales. Patients with pure motor variant and Miller- Fisher syndrome showed higher sNfL levels than patients with sensory-motor GBS (162.18pg/mL vs 95.50pg/mL vs 38.02pg/mL; p=0.025). AMAN patients had higher sNfL levels than other variants (190.55pg/mL vs 46.79pg/mL, p=0.013). sNfL returned to normal levels at one year. High baseline sNfL levels were associated with inability to run (OR=1.65, 95% CI 1.14-2.40, p=0.009) and lower R-ODS ({beta} -2.60, 95% {beta} -4.66-(-0.54), p=0.014) at one year. Cut-off points predicting clinically relevant outcomes at one year with high specificity were calculated: inability to walk independently (>319pg/mL), inability to run (>248pg/mL) and ability to run (<34pg/mL). ConclusionBaseline sNfL levels are increased in patients with GBS, they are associated with disease severity and axonal variants and they have an independent prognostic value in GBS patients.