Studying serum neurofilamen light chain levels as a potential new biomarker for small fiber neuropathy

Background and purposeDiagnosing small fiber neuropathies can be challenging. To address this issue, whether serum neurofilament light chain (sNfL) could serve as a potential biomarker of damage to epidermal A delta- and C-fibers was tested.MethodsSerum NfL levels were assessed in 30 patients diagnosed with small fiber neuropathy and were compared to a control group of 19 healthy individuals. Electrophysiological studies, quantitative sensory testing and quantification of intraepidermal nerve fiber density after skin biopsy were performed in both the proximal and distal leg.ResultsSerum NfL levels were not increased in patients with small fiber neuropathy compared to healthy controls (9.1 +/- 3.9 and 9.4 +/- 3.8, p = 0.83) and did not correlate with intraepidermal nerve fiber density at the lateral calf or lateral thigh or with other parameters of small fiber impairment.ConclusionSerum NfL levels cannot serve as a biomarker for small fiber damage.