European Journal of Neurology | January 24, 2023

Mens, H., Fjordside, L., Gynthersen, R., Ørbæk, M., Andersen, Å.B., Andreasson, U., Blennow, K., Sellebjerg, F., Zetterberg, H. and Lebech, A.-M.

Eur J Neurol. Accepted Author Manuscript.

https://doi.org/10.1111/ene.15707

Abstract

Background

Currently there is an unmet need for a highly standardized blood biomarker test to monitor treatment response in Lyme neuroborreliosis (LNB). Differentiating between active or past infection is challenged by the relatively high frequency of persistent symptoms after the end of antibiotic treatment (estimated 15-20%), variable clinical course and the long-lasting B. burgdorferi antibodies. We therefore wanted to evaluate plasma NfL as a marker for disease activity in LNB.

Methods

Prospective included cohort of definite LNB (N=36) with blood samples and clinical evaluation including Glasgow Outcome Score (GOS) at treatment initiation, 3- and 6-months follow-up. Consecutive plasma was retrospectively analyzed for the content of NfL by Quanterix® kits (Simoa® NF-light Kit).

Results

pNfL significantly decreased between treatment initiation and 3-months follow-up (median 83 pg/ml vs median 14 pg/ml (25 pairs), p<0.0001). No significant change was observed between 3- and 6-months follow-up (median 14 pg/ml vs median 12 pg/ml (21 pairs), p=0.33). At treatment initiation 90% had pNfL above the age defined reference compared to only 23% and 7% respectively at 3- and 6-months follow-up. Decreases in pNfL were mirrored by increasing GOS. Reporting persistent symptoms at the 6 months follow-up was not associated with plasma NfL (relative change from reference or actual values) at baseline or at 6 months follow-up

Conclusion

pNfL decreases following antibiotic treatment in LNB and is not associated with reporting persistent symptoms. We therefore speculate that it may prove useful as a treatment response biomarker in LNB.