Cerebrospinal fluid and urinary biomarkers in multiple sclerosis

Objectives Biomarkers with the potential for longitudinal measurements are needed in multiple sclerosis ( MS ). Urine is easy to collect, and repeated sampling is possible. Methods 39 paired CSF and urine samples were taken. Oligoclonal bands ( OCB s) were measured in CSF . Kappa and lambda free light chain ( FLC ), neopterin and ubiquitin C‐terminal hydrolase‐L1 ( UCHL 1) were measured in CSF and urine. Results 16/39 samples had OCB s unique to the CSF . CSF FLC levels ( P  < 0.0001) were higher in OCB ‐positive subjects, with no difference in urinary FLC . CSF and urinary FLC did not correlate. There were a significant correlation between total CSF FLC and CSF neopterin in MS samples (correlation coefficient = 0.588, P  = 0.016) and a strong correlation between CSF lambda FLC and CSF neopterin in MS samples (correlation coefficient = 0.875, P  < 0.001). There was a strong correlation between urinary neopterin/creatinine levels and urinary total FLC /protein levels (correlation coefficient = 0.452, P  = 0.004). Only three CSF samples (8%) had detectable levels of UCHL 1. 18/38 (48%) (8/15 MS and 10/23 control) urine samples had detectable levels of UCLH 1. Conclusions This study confirms the relationship between CSF OCB s and CSF FLC s, highlighting the importance of intrathecal B‐ and plasma‐cell activation in MS . There is a relationship between CSF FLC and CSF neopterin in MS , highlighting the multifaceted immune activation seen in MS . Correlations in the OCB ‐positive group highlight the multifaceted immune activation seen in MS . Further studies are required to evaluate CSF and urinary biomarkers.