Cytokine and chemokine profiles in neuromyelitis optica: significance of interleukin-6.

BACKGROUND

Neuromyelitis optica (NMO) is assumed to be immunologically distinct from multiple sclerosis (MS). Adequate studies about cytokines and chemokines in NMO have been lacking.

OBJECTIVE

To investigate the contribution of cytokines/chemokines in the pathogenesis of NMO.

METHODS

We measured 27 cytokines/chemokines and Th17 cell-associated cytokines in the cerebrospinal fluid (CSF) of 31 NMO, 29 MS and 18 other non-inflammatory neurological disorders patients. The serum levels of some cytokines/ chemokines were also measured. The correlations between clinical characteristics/laboratory findings and levels of cytokines/chemokines in NMO were examined.

RESULTS

The CSF levels of interleukin (IL)-1 receptor antagonist, IL-6, IL-8, IL-13 and granulocyte colony-stimulating factor were significantly increased in NMO, while IL-9, fibroblast growth factor-basic, granulocyte macrophage colony-stimulating factor, macrophage inflammatory protein-1-beta and tumor necrosis factor-alpha were increased in MS. IL-10 and interferon-gamma-inducible protein-10 were elevated in NMO and MS. In serum analyses, only the IL-6 level showed significant elevation in NMO. The CSF IL-6 level had a significant correlation with the CSF glial fibrillary acidic protein level and CSF cells, and a weak correlation with anti-aquaporin-4 antibody titers.

CONCLUSIONS

Different immunological status and pathophysiologies exist between NMO and MS, and IL-6 may play important roles in the pathogenesis of NMO.