Evaluating the feasibility of a remote sampling method for neurofilament light chain measurements in Multiple Sclerosis

Abstract

BACKGROUND/OBJECTIVES: Neurofilament light (NfL) is a biomarker of axonal damage, typically measured in CSF or venous blood. There is growing interest in the utility of remote sampling methods however limited studies of feasibility exist. METHODS: 45 people with MS undergoing lumbar puncture were recruited and had at least one sample included. NfL levels from different biofluids and sampling methods were examined at baseline: CSF (n = 43), venous plasma (n = 29) and finger-prick dried plasma spots (fDPS, n = 39). Participants were then asked to self-collect fDPS at two, four and six months after enrolment. RESULTS: Levels of NfL were highest in CSF with a geometric mean of 449.78 pg/ml (95% CI 334.25-605.26) compared to plasma, 71.48 pg/ml (95% CI 57.04-89.57) or fDPS 4.02pg/ml (95% CI 3.03-5.36). There was a strong correlation between CSF and venous plasma NfL, (r = 0.78, r(2)=0.61, p < 0.001); and venous plasma and fDPS NfL, (r = 0.71, r(2)=0.50, p < 0.005); and a moderate correlation between CSF and fDPS, (r = 0.44, r(2)=0.20, p < 0.05). CONCLUSION: Remote self-collection of fDPS was feasible in our study with NfL levels strongly correlating with plasma while capturing CSF trends. Additionally, NfL remained stable over six months in a clinically stable population, supporting the reliability of the assay.