Data from: Association of serum neurofilament light (sNfL) and disease severity in patients with spinocerebellar ataxia type 3

<p><a name="_Hlk22462511"><b>Objective:</b></a> To investigate serum neurofilament light protein (sNfL) levels in patients with spinocerebellar ataxia type 3 (SCA3) and to determine whether they are associated with disease severity.</p> <p><b>Methods: </b>This cross-sectional study enrolled 185 healthy controls and 235 <i>ATXN3</i> mutation carriers (17 asymptomatic stage, 20 preclinical stage, and 198 ataxic stage)<span class="fontstyle01"><span>. We measured </span></span>sNfL levels with the single molecule array (Simoa) platform. Clinical disease severity was assessed using the scale of assessment and rating of ataxia (SARA) and the inventory of non-ataxia signs (INAS). In a subgroup of 50 ataxic stage patients, we further evaluated the gray matter volume and the integrity of white matter fibers by magnetic resonance imaging (MRI).</p> <p><b>Results:</b> sNfL concentrations were elevated in asymptomatic, preclinical,<i> </i>and<i> </i>ataxic<i> ATXN3</i> mutation carriers compared to controls (12.18 [10.20-13.92], 21.84 [18.37-23.45], 36.06 [30.04-45.90] and 8.24 [5.92-10.84] pg/mL, median [interquartile range], respectively, <i>P </i>&lt; 0·001). sNfL correlated with SARA (r=0.406, 95% confidence interval 0.284-0.515, <span class="fontstyle01"><span><i>P </i></span></span><span class="fontstyle01"><span>&lt; 0.0001</span></span>) and INAS (r=0.375, 95% confidence interval 0.250-0.487, <span class="fontstyle01"><span><i>P </i></span></span><span class="fontstyle01"><span>&lt; 0.0001</span></span>), and remained significant after adjustment for age and CAG repeats. In addition, we observed negative correlations of the sNfL with gray matter volume in the left precentral gyrus and the left paracentral lobule as well as with the mean diffusivity in widespread white matter tracts.</p> <p><b>Conclusion: </b>Our results demonstrate that sNfL levels are increased in <span class="fontstyle01"><span>SCA3</span></span> and are associated with clinical disease severity, which supports sNfL as a biomarker for disease severity in SCA3.</p>