Therapeutic Advances in Neurological Disorders (May 2021)

Serum neurofilament levels reflect outer retinal layer changes in multiple sclerosis

  • Caspar B. Seitz,
  • Falk Steffen,
  • Muthuraman Muthuraman,
  • Timo Uphaus,
  • Julia Krämer,
  • Sven G. Meuth,
  • Philipp Albrecht,
  • Sergiu Groppa,
  • Frauke Zipp,
  • Stefan Bittner,
  • Vinzenz Fleischer

DOI
https://doi.org/10.1177/17562864211003478
Journal volume & issue
Vol. 14

Abstract

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Background: Serum neurofilament light chain (sNfL) and distinct intra-retinal layers are both promising biomarkers of neuro-axonal injury in multiple sclerosis (MS). We aimed to unravel the association of both markers in early MS, having identified that neurofilament has a distinct immunohistochemical expression pattern among intra-retinal layers. Methods: Three-dimensional (3D) spectral domain macular optical coherence tomography scans and sNfL levels were investigated in 156 early MS patients (female/male: 109/47, mean age: 33.3 ± 9.5 years, mean disease duration: 2.0 ± 3.3 years). Out of the whole cohort, 110 patients had no history of optic neuritis (NHON) and 46 patients had a previous history of optic neuritis (HON). In addition, a subgroup of patients ( n = 38) was studied longitudinally over 2 years. Support vector machine analysis was applied to test a regression model for significant changes. Results: In our cohort, HON patients had a thinner outer plexiform layer (OPL) volume compared to NHON patients ( B = −0.016, SE = 0.006, p = 0.013). Higher sNfL levels were significantly associated with thinner OPL volumes in HON patients ( B = −6.734, SE = 2.514, p = 0.011). This finding was corroborated in the longitudinal subanalysis by the association of higher sNfL levels with OPL atrophy ( B = 5.974, SE = 2.420, p = 0.019). sNfL levels were 75.7% accurate at predicting OPL volume in the supervised machine learning. Conclusions: In summary, sNfL levels were a good predictor of future outer retinal thinning in MS. Changes within the neurofilament-rich OPL could be considered as an additional retinal marker linked to MS neurodegeneration.