IL-15 is elevated in serum and cerebrospinal fluid of patients with multiple sclerosis

J Neurol Sci. 2006 Feb 15;241(1-2):25-9. doi: 10.1016/j.jns.2005.10.003. Epub 2005 Nov 28.


Interleukin-15 (IL-15) is a novel proinflammatory cytokine having similar biological activities to IL-2 which is implicated in the pathogenesis of multiple sclerosis. It is produced by activated blood monocytes, macrophages and glial cells. There is little information about the involvement of IL-15 in the development of multiple sclerosis (MS). The objective of our study was to measure IL-15 serum and cerebrospinal fluid (CSF) levels in MS patients and to correlate serum and CSF IL-15 concentrations with clinical parameters of the disease. CSF IL-15/Serum IL-15 ratio (c/s IL-15 ratio) was introduced to assess the origin of elevated IL-15 levels.

Materials and methods: We measured serum and CSF IL-15 levels in 52 patients with MS and 36 age and gender matched patients with inflammatory (IND) and non-inflammatory neurological diseases (NIND) studied as control groups. IL-15 levels were correlated with clinical parameters as duration, disability, MRI activity and clinical subtypes of the disease.

Results: MS patients were found to have significantly higher serum IL-15 levels compared with IND (p=0.00016) and NIND patients (p=0.00045). Elevated levels of IL-15 were also found in CSF samples from MS patients compared with patients with IND (p=0.00034) and NIND (p=0.0003). Among MS subgroups there were no statistically different IL-15 serum and CSF concentrations. No significant correlation of serum and CSF IL-15 concentrations with MRI activity, disability assessed by EDSS score and duration of the disease were also found. C/S IL-15 ratio was found lower in MS patients compared with IND (p=0.01) and not significantly different compared with NIND patients (p=0.14) suggesting that systemic activation might be the source of high CSF IL-15 levels in MS patients.

Conclusions: Our findings suggest a possible role of IL-15 in the immunopathogenetic mechanisms of MS.

Publication types

  • Comparative Study

MeSH terms

  • Adolescent
  • Adult
  • Case-Control Studies
  • Enzyme-Linked Immunosorbent Assay / methods
  • Female
  • Humans
  • Interleukin-5 / blood*
  • Interleukin-5 / cerebrospinal fluid*
  • Male
  • Middle Aged
  • Multiple Sclerosis / blood*
  • Multiple Sclerosis / cerebrospinal fluid*
  • Nervous System Diseases / blood
  • Nervous System Diseases / cerebrospinal fluid
  • Statistics, Nonparametric


  • Interleukin-5