IL-6 as a Biomarker in MS

Wullschleger A, Kapina V, Molnarfi N, Courvoisier DS, Seebach JD, Santiago-Raber ML, Hochstrasser DF, Lalive PH.Cerebrospinal fluid interleukin-6 in central nervous system inflammatory diseases.PLoS One. 2013 Aug; 8(8):e72399. doi: 10.1371/journal.pone.0072399.

BACKGROUND: Interleukin (IL)-6 is recognised as an important cytokine involved in inflammatory diseases of the central nervous system (CNS).
OBJECTIVE: To perform a large retrospective study designed to test cerebrospinal fluid (CSF) IL-6 levels in the context of neurological diseases, and evaluate its usefulness as a biomarker to help discriminate multiple sclerosis (MS) from other inflammatory neurological diseases (OIND).
PATIENTS AND METHODS: 
We analyzed 374 CSF samples for IL-6 using a quantitative enzyme-linked immunosorbent assay. Groups tested were composed of demyelinating diseases of the CNS (DD, n = 117), including relapsing-remitting MS (RRMS, n = 65), primary progressive MS (PPMS, n = 11), clinically isolated syndrome (CIS, n = 11), optic neuritis (ON, n = 30); idiopathic transverse myelitis (ITM, n = 10); other inflammatory neurological diseases (OIND, n = 35); and non-inflammatory neurological diseases (NIND, n = 212). 
RESULTS: CSF IL-6 levels exceeded the positivity cut-off of 10 pg/ml in 18 (51.4%) of the 35 OIND samples, but in only three (3.9%) of the 76 MS samples collected. CSF IL-6 was negative for all NIND samples tested (0/212). IL-6 cut-off of 10 pg/ml offers 96% sensitivity to exclude MS.
CONCLUSION: CSF IL-6 may help to differentiate MS from its major differential diagnosis group, OIND.
Interleukin 6 (IL-6) acts as both a pro-inflammatory and an anti-inflammatory cytokine. It can cause fever and is a T cell (Th17) and B cell growth and differentiation factor. Lack of the presence of a cytokine does not necessarily mean it is not there as it may have been mopped up by the target receptor. 

Labels: