Neurofilament light chain improves clinical prognostic models for Guillain-Barré syndrome

Background: Several prognostic models predict clinical outcomes in Guillain-Barré syndrome (GBS). Recently, neurofilament light chain (NfL) has emerged as a prognostic biomarker. We investigated the added prognostic value of NfL in serum (sNfL) and cerebrospinal fluid (cNfL) to models based on clinical factors predicting respiratory failure and inability to walk in GBS. Methods: We included patients from a randomised placebo-controlled trial (second intravenous immunoglobulin dose in GBS). Serum was acquired at entry and week 1, 2, 4 and 12 and cerebrospinal fluid at entry. NfL levels were determined on a single molecule array. The additional prognostic value of NfL to the (modified) Erasmus GBS Outcome Score ((m)EGOS) and (modified) Erasmus GBS Respiratory Insufficiency Score was evaluated using logistic regression analyses. Results: In total, 293 patients were included (74 (25%) mechanically ventilated, 38/275 (13%) unable to walk at 26 weeks). Higher sNfL at entry, week 1 and week 2 and cNfL at entry were associated with inability to walk at 4 and 26 weeks. Neither sNfL nor cNfL levels at entry were associated with respiratory failure. The EGOS and mEGOS improved after adding NfL (C-statistic range: 0.01-0.11), especially the models predicting outcome at 26 weeks. A new model predicting inability to walk at 26 weeks consisting of sNfL at entry, GBS disability score at entry and Medical Research Council sum score at week 2 performed best (C-statistic: 0.88 (95% CI 0.83 to 0.94)). Conclusions: Addition of NfL may improve clinical prognostic models for the prediction of inability to walk, but not of respiratory failure.