Serum neurofilament light chain predicts disease severity in axonal variants of acute immune neuropathies: A retrospective monocentric cohort study

Abstract

Background and purpose: The purpose was to explore the prognostic utility of neurofilament light chain (NfL) in patients with immune-mediated polyradiculoneuropathies (IMPs).

Methods: This retrospective monocentric study analysed serum and cerebrospinal fluid samples from patients diagnosed with IMP collected prior to treatment initiation. NfL concentrations were correlated with clinical outcomes, including F score and hospitalization duration.

Results: Amongst 115 IMP patients tested, baseline cerebrospinal fluid and serum NfL (sNfL) concentrations were higher in acute inflammatory axonal polyradiculoneuropathy (AIAP) than other IMP variants. In the AIAP cohort, a positive correlation was observed between baseline sNfL concentrations, F score and hospitalization duration. Multivariate linear regression analysis further supported the predictive relationship between elevated baseline sNfL concentrations and clinical outcomes. Using receiver operating characteristic analysis, a cut-off value for sNfL of 351 pg/mL was found to predict an F score >3 in AIAP with a sensitivity of 40% and specificity of 81.8%. AIAP patients with sNfL concentrations above this threshold required longer hospitalization (extended by 15 days).

Discussion: Our findings highlight the potential of baseline sNfL as an effective marker for distinguishing between IMP variants and predicting the prognosis of AIAP. Further validation may facilitate translation of sNfL into clinical practice, potentially identifying high-risk patients for tailored treatment approaches.

Keywords: GBS; NfL; acute axonal immune neuropathy; immune neuropathies.

FIGURE 1

Serum neurofilament light chain (sNfL) concentrations correlate with disease severity in acute inflammatory axonal polyneuropathy (AIAP). (a) Serum and (b) CSF samples from patients with immune‐mediated neuropathies obtained during initial presentation were preserved in our local biobank and tested for neurofilament light chain (NfL) with the Quanterix Simoa kit according to the manufacturer's protocol. Data are shown as box and whisker plots, following the Tukey method tested with the Kruskal–Wallis test and corrected for multiple testing with (a) Dunn's test and (b) the Mann–Whitney U test. *p < 0.05, ****p < 0.0001. sNfL concentration was found to correlate with disease severity (F score) (c) and hospitalization duration (d) in patients with AIAP. The data were computed using the Spearman correlation coefficient. sNfL concentrations were associated with F score and hospitalization duration in a multivariate linear regression model adjusted for age, sex, the duration of symptoms, CSF/serum albumin quotient (Q _Alb), sNfL and plasmapheresis (e). The prognostic value of sNfL for an F score greater than 3 was analysed using a ROC curve to determine cut‐off values and their corresponding sensitivity and specificity (f). sNfL concentrations above 351 pg/mL were associated with longer hospitalization durations, as tested with the Mantel–Cox log‐rank and Gehan–Breslow–Wilcoxon tests (g). AIAP, acute immune‐mediated axonal polyneuropathy; AIDP, acute immune‐mediated demyelinating polyneuropathy; AUC, area under the curve; CIDP, chronic immune‐mediated demyelinating polyneuropathy; MFS, Miller–Fisher syndrome; Q _Alb, albumin quotient CSF and serum; SE, standard error; ROC, receiver operating characteristic.