thanks you both!!!
An update to this thread
Serum Neurofilament-Light As Good As CSF for Monitoring Disease Activity in MS
http://journals.lww.com/neurotodayonlin ... PostID=675
Levels of neurofilament-light (NfL) protein in serum and cerebrospinal fluid (CSF) were highly correlated in patients with multiple sclerosis (MS), according to a study published online on October 27 in Neurology.
Previous research has shown that CSF levels of NfL correlate with markers of MS disease activity, such as relapses and contrast-enhancing lesions on magnetic resonance imaging, and decrease with disease-modifying therapies (DMTs). Serum levels of NfL have been shown to be a promising biomarker for conditions including traumatic brain injury and sports-related concussion, but a blood biomarker for central nervous system damage in MS is still lacking.
The findings suggest that "blood sampling can replace CSF taps for this particular marker," the study authors, led by Lenka Novakova, MD, of the University of Gothenburg in Sweden, wrote. "In combination with clinical and MRI monitoring, serum NFL can add valuable new information that will facilitate the monitoring of disease activity and treatment decisions in MS."
For the study, researchers recruited 373 patients from four hospitals in Sweden, including 286 patients with MS, 45 patients with other neurologic disorders or symptoms, and 42 healthy controls. They obtained serum and CSF samples from each; in 138 patients with MS, the samples were collected before and after DMT treatment with a median interval of 12 months. They used the UmanDiagnostics NfL enzyme-linked immunosorbent assay to assess NfL concentration in the CSF, and used an in-house ultrasensitive single-molecule array assay to assess NFL concentration in serum.
They found that among the patients with MS, the correlation between serum and CSF NFL was r=0.62 (p<0.001). Serum concentrations of NfL were significantly higher in patients with relapsing-remitting MS (16.9 ng/L) and in patients with progressive MS (23 ng/L) compared to healthy controls (10.5 ng/L, p<0.001 and p<0.001, respectively).
Furthermore, they found that disease activity and DMTs had similar effects on serum and CSF concentrations of NfL. Treatment with DMTs reduced median serum NFL levels from 18.6 (interquartile range [IQR] 12.6–32.7) ng/L to 15.7 (IQR 9.6–22.7) ng/L (p<0.001). Patients with who had relapses or radiologic activity had significantly higher serum NFL levels compared to patients in remission (p<0.001) or who did not have new lesions on MRI (p<0.001).
Even patients who had no evidence of disease activity had elevated levels of NfL, the study authors noted, which suggests that NfL determinations "add new information that other methods may not be able to reveal… NfL and other body fluid biomarkers as complements to current clinical and MRI measures might improve the assessment of disease activity in MS."