Cerebrospinal Fluid and Serum Neuron-Specific Enolase in Niemann-Pick Disease Type C1.

Niemann-Pick disease, type C1 (NPC1) is an ultra rare, autosomal recessive disorder characterized by impaired intracellular cholesterol trafficking. This study assessed neuron-specific enolase (NSE) as a biomarker for disease status and treatment response in individuals with NPC1. We also evaluated the concordance between serum and cerebrospinal fluid (CSF) NSE measurements. A total of 34 individuals with NPC1 were included in this analysis. Overall, 10 participants were used to compare concurrent samples of CSF and serum NSE. NSE levels were correlated with indexes of disease severity (Annual Severity Increment Score [ASIS] and age of neurological onset) and disease burden (NPC Neurological Severity Score [NSS]). NSE was elevated in CSF, but paired CSF/serum samples were not correlated (r  = -0.16, p = 0.64). Additionally, no significant correlations were observed between serum NSE levels and clinical measures of either disease burden or severity. CSF NSE values showed a significant positive association with the ASIS (r  = 0.37, p = 0.0291) but no association with age of neurological onset or NPC NSSs. Longitudinal analysis of nine participants showed a significant (p = 0.0317) decrease in CSF NSE levels after initiation of intrathecal 2-hydroxypropyl-β-cyclodextrin (IT HPβCD) therapy. This study suggests that CSF NSE may have some utility as a biomarker in NPC1 therapeutic trials.