Background: The objective of this study
was to assess neurofilament light chain as a Parkinson’s
disease biomarker.
Methods: We quantified neurofilament light chain in
2 independent cohorts: (1) longitudinal cerebrospinal fluid
samples from the longitudinal de novo Parkinson’s disease cohort and (2) a large longitudinal cohort with serum
samples from Parkinson’s disease, other cognate/neurodegenerative disorders, healthy controls, prodromal conditions, and mutation carriers.
Results: In the Parkinson’s Progression Marker Initiative
cohort, mean baseline serum neurofilament light chain
was higher in Parkinson’s disease patients (13 � 7.2
pg/mL) than in controls (12 � 6.7 pg/mL), P = 0.0336.
Serum neurofilament light chain increased longitudinally in
Parkinson’s disease patients versus controls (P < 0.01).
Motor scores were positively associated with neurofilament light chain, whereas some cognitive scores
showed a negative association.
Conclusions: Neurofilament light chain in serum samples is increased in Parkinson’s disease patients versus healthy controls, increases over time and with age,
and correlates with clinical measures of Parkinson’s
disease severity. Although the specificity of neurofilament light chain for Parkinson’s disease is low, it
is the first blood-based biomarker candidate that could
support disease stratification of Parkinson’s disease
versus other cognate/neurodegenerative disorders,
track clinical progression, and possibly assess responsiveness to neuroprotective treatments. However, use of
neurofilament light chain as a biomarker of response
to neuroprotective interventions remains to be assessed