Treatment with hydroxychloroquine for 6 months attenuates elevations in neurofilament light chain and glial fibrillary acidic protein levels for up to 18 months in patients with primary progressive multiple sclerosis (MS), a new study published in the European Journal of Neurology found. This finding suggests that hydroxychloroquine has an effect on these biomarkers.

The authors of the study also reported that the thickness of the retinal nerve fiber layer, a marker of neuroaxonal atrophy, was associated with the worsening of disability and “should be explored further as a prognostic marker.”

The effect of hydroxychloroquine in reducing the worsening of disability in primary progressive MS was shown in a recent clinical trial.


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In the present study, a team of researchers led by Marcus Koch, MD, PhD, from the Department of Clinical Neurosciences at the University of Calgary in Canada explored the roles of neurofilament light chain and glial fibrillary acidic protein as potential biomarkers in MS.

The researchers measured the levels of these 2 proteins at different time points over 18 months in the serum of 39 patients with inactive primary progressive MS who were treated with hydroxychloroquine as part of a phase 2 clinical trial. They then explored the link between these levels and the degree of disability. They also measured and analyzed the thickness of the retinal nerve fiber layer at 12 months. 

The results showed that the levels of neurofilament light chain and glial fibrillary acidic protein increased with time. However, this was only significant from screening to month 6, not from month 6 to month 18. 

The levels of these 2 proteins did not correlate with the degree of disability as measured by the Expanded Disability Status Scale (EDSS) at screening. Levels of glial fibrillary acidic protein did moderately correlate with the timed 25-foot walk but not those of neurofilament light chain.

While screening levels of neurofilament light chain and glial fibrillary acidic protein could not predict the worsening of disability at month 18, the thickness of the retinal nerve fiber layer could.

The authors concluded that their results suggest that “additional studies are needed to explain disparities between these biomarkers and clinical measures of disability and progression” and that the thickness of the retinal nerve fiber layer “warrants further exploration as a predictive biomarker.”

Reference

Camara-Lemarroy C, Silva C, Gohill J, Yong VW, Koch M. Serum neurofilament-light and glial fibrillary acidic protein levels in hydroxychloroquine treated primary progressive multiple sclerosis. Eur J Neurol. Published online October 10, 2022. doi:10.1111/ene.15588