PT - JOURNAL ARTICLE AU - Carolina Rosadas AU - Henrik Zetterberg AU - Amanda Heslegrave AU - Jana Haddow AU - Mina Borisova AU - Graham P. Taylor TI - Neurofilament Light in CSF and Plasma Is a Marker of Neuronal Damage in HTLV-1–Associated Myelopathy and Correlates With Neuroinflammation AID - 10.1212/NXI.0000000000001090 DP - 2021 Nov 01 TA - Neurology - Neuroimmunology Neuroinflammation PG - e1090 VI - 8 IP - 6 4099 - http://nn.neurology.org/content/8/6/e1090.short 4100 - http://nn.neurology.org/content/8/6/e1090.full SO - Neurol Neuroimmunol Neuroinflamm2021 Nov 01; 8 AB - Background and Objectives To evaluate the usefulness of CSF and plasma neurofilament light (Nf-L) as a biomarker for human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy (HAM).Methods Nf-L, CXCL10, and neopterin were measured by ELISA in 83 CSF samples obtained from 49 individuals living with HTLV-1/2. Plasma Nf-L was also measured by single molecule array. Results were correlated with duration of disease, age, mobility, CSF cell counts, CSF protein, and HTLV-1 proviral load.Results Nf-L was detected in all CSF samples (median [range] = 575 [791.8–2,349] pg/mL) and positively correlated with markers of inflammation (CXCL10 (r = 0.733), neopterin (r = 0.499), cell count (r = 0.403), and protein levels (r = 0.693) in CSF; p < 0.0015). There was an inverse correlation between Nf-L and duration of disease (r = −0.584, p < 0.0001). Wheelchair-dependent patients had high concentrations of markers of inflammation and neuronal damage. Concentrations of CXCL10, neopterin, and Nf-L remained elevated in follow-up samples (mean follow-up 5.2 years). Nf-L in plasma correlated with concentration of Nf-L, neopterin, CXCL10, and protein in CSF.Conclusions Nf-L in plasma and CSF has potential to be used as a biomarker of disease activity in HAM. Neuronal damage seems to be more intense early in disease but persists long term. Wheelchair-dependent patients have ongoing neuroinflammation.HAM=HTLV-1–associated myelopathy; HTLV-1=human T-cell lymphotropic virus type 1; Nf-L=neurofilament light; SIMOA=single molecule array