Longitudinal treatment responsiveness on plasma neurofilament light chain and glial fibrillary acidic protein levels in neuromyelitis optica spectrum disorder

Tian-Xiang Zhang; Jing-Shan Chen; Chen Du; Pei Zeng; Huiming Zhang; Xuejiao Wang; Ye Liu; Zhenning Huang; Meng Yuan; Yu-Lin Li; Dongmei Jia; Fu-Dong Shi; Chao Zhang

doi:10.1177/17562864211054952

Longitudinal treatment responsiveness on plasma neurofilament light chain and glial fibrillary acidic protein levels in neuromyelitis optica spectrum disorder

Ther Adv Neurol Disord. 2021 Nov 3:14:17562864211054952. doi: 10.1177/17562864211054952. eCollection 2021.

Authors

Affiliations

¹ Department of Neurology, Tianjin Medical University General Hospital, Tianjin Neurological Institute, Tianjin, P.R. China.
² Department of Neurology, The Third People's Hospital of Datong, Datong, China.
³ Department of Neurology, Tianjin Medical University General Hospital, Tianjin Neurological Institute, Tianjin 300052, P.R. China.

Abstract

Background: Neurofilament light chain (NfL) and glial fibrilliary acidic protein (GFAP) have been suggested to be biomarkers of the pathophysiological process of neuromyelitis optica spectrum disorders (NMOSD), but the relationship between the plasma levels of these molecules with disease activity and treatment is incompletely understood.

Objective: To investigate the treatment effects of disease-modifying drugs on plasma neurofilament light chain (pNfL) and plasma glial fibrillary acidic protein (pGFAP) and explore the predictive value of pNfL and pGFAP in the activity of NMOSD.

Methods: pNfL and pGFAP levels were measured using single-molecule arrays in 72 patients with NMOSD and 38 healthy controls (HCs). Patients with NMOSD received tocilizumab (n = 29), rituximab (n = 23), oral prednisone (n = 16), and oral azathioprine or mycophenolate mofetil (n = 4).

Results: NMOSD patients had significantly higher pNfL and pGFAP levels than HCs (pNfL, 18.3 (11.2-39.3) versus 11.5 (7.0-23.3) pg/mL; p = 0.001; pGFAP, 149.7 (88.6-406.5) versus 68.7 (59.4-80.8) pg/mL; p < 0.001). Multivariable regression analyses indicated that baseline pNfL concentration was associated with age (p = 0.017), Expanded Disability Status Scale (EDSS) score (p = 0.002), and recent relapses (p < 0.001). Baseline pGFAP concentration was also associated with EDSS (p < 0.001) and recent relapses (p < 0.001). Compared with prednisone, tocilizumab and rituximab significantly reduced pNfL [tocilizumab, exp(β), 0.65; 95% confidence interval (CI), 0.56-0.75; p < 0.001; rituximab, exp(β), 0.79; 95% CI = 0.68-0.93; p = 0.005] and pGFAP levels [tocilizumab, exp(β), 0.64; 95% CI, 0.51-0.80; p < 0.001; rituximab, exp(β), 0.77; 95% CI, 0.61-0.98; p = 0.041] at the end of the study. The pNfL levels in the tocilizumab and rituximab groups were reduced to those of HCs [tocilizumab, 8.5 (7.06-17.90) pg/mL; p = 0.426; rituximab, 14.0 (9.94-21.80) pg/mL; p = 0.216]. However, the pGFAP levels did not decrease to those of HCs in NMOSD patients at the end of study [tocilizumab, 88.9 (63.4-131.8) pg/mL; p = 0.012; rituximab, 141.7 (90.8-192.7) pg/mL; p < 0.001].

Conclusion: pNfL and pGFAP may serve as biomarkers for NMOSD disease activity and treatment effects.

Keywords: NMOSD; glial fibrillary acidic protein; neurofilament light chain; treatment response.