Evaluating the Correlation Between Spinal Fluid and Blood Levels of Neurofilament Light, GFAP, Tau, and UCHL1: Do We Need a Correction Factor in Evaluating Blood Levels? (4912)

Objective: To evaluate factors contributing to blood and cerebrospinal fluid(CSF) discordance and determine if a correction of blood levels can better estimate what is happening in the CSF compartment. Background: Plasma neurofilament light(pNFL) levels account for 30–60% of the variance in CSF neurofilament light(cNFL) levels depending on the study. Age, disability, relapses, and the presence of contrast enhancing MRI lesions can increase both pNFL and cNFL. Additional nervous system biomarkers can now be studied in plasma. Understanding the factors that increase their variability in blood may be helpful in normalizing levels to better understand what levels are concerning for ongoing disease activity. Design/Methods: Matched plasma and CSF samples were identified in the Rocky Mountain Multiple Sclerosis Center Biorepository at the University of Colorado. Neurofilament Light(NFL), Glial Fibrillary Acidic Protein(GFAP), tau, and Ubiquitin carboxy-terminal hydrolase L1(UCHL1) levels were assessed using Single Molecule Array(SIMOA) in a Quanterix SR-X machine. Analyses were done on log transformed NFL concentrations. Results: Fifty-seven patients had matched plasma and cerebrospinal fluid samples evaluated for neurofilament light which included 24 patients with multiple sclerosis(MS), 7 with neuromyelitis optica spectrum disorder(NMOSD), and 18 patients with headache whose opening pressures were Conclusions: Blood and CSF levels of NFL, GFAP, tau, and UCHL1 correlated well. Models will be created that explore the relationship between Blood and CSF levels of these biomarkers. Disclosure: Dr. Alvarez has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with consulting fees from Actelion, Bayer, Biogen, Celgene, EMD Serono, Genentech, Genzyme, Novartis, and TG Therapeutics. Dr. Alvarez has received research support from Biogen, Genentech, Novartis, TG Therapeutics, and Rocky Mountain MS Center.Dr. Ritchie has nothing to disclose. Dr. Nair has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Celgene, Genentech, Novartis, Gilead. Dr. Nair has received research support from Genentech, Biogen.Dr. Gross has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with AP Expert Group.Dr. Piquet has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Sanofi Genzyme and honorarium from MedLink. Dr. Piquet has received research support from Drake Family through the Children’s Hospital Colorado Foundation and research funding from the Rocky Mountain MS Center.. Dr. Knapp has nothing to disclose. Dr. Selva has nothing to disclose. Dr. Sillau has nothing to disclose. Dr. Bennett has received personal compensation from Alexion, Chugai, Clene Nanomedicine, Equillium, Frequency Therapeutics, Genentech, Roche, MedImmune/Viela Bio, Novartis. Dr. Bennett has received royalty, license fees, or contractual rights payments from Aquaporumab. Dr. Bennett has received research support from EMD Serono, Novartis.Dr. Owens has received research support from EMD Serono.Dr. Vollmer has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Biogen Idec, Genentech-Roche, Siranax, Celgene, EMD Serono, Novartis. Dr. Vollmer has received research support from Rocky Mountain MS Center, Biogen, Actelion, F. Hoffman -La Roche, TG Therapeutics.