Elevated serum interleukin-39 levels in patients with neuromyelitis optica spectrum disorders correlated with disease severity

Aims: Neuromyelitis optica spectrum disorders (NMOSD) is an inflammatory demyelinating autoimmune disorder in the central nervous system (CNS), which is mainly mediated by aquaporin 4 antibodies (AQP4-Ab). Interleukin (IL)-39 is a new pro-inflammatory cytokine which belongs to the IL-12 cytokine family. However, the role of IL-39 in patients with NMOSD is not completely understood. Therefore, the aim of this study is to explore the possible implication of IL-39 in the pathogenesis of NMOSD. Methods: In this study, 50 patients with NMOSD, 20 patients with relapsing-remitting multiple sclerosis (RRMS), 30 patients with non-inflammatory neurological disorders (NND) and 78 healthy controls (HCs) were recruited. The levels of serum IL-39 were measured using the enzyme-linked immunosorbent assay (ELISA). Results: Our study showed serum IL-39 levels in patients with NMOSD were significantly higher than that in RRMS patients, NND patients and HCs, and positively correlated with Expanded Disability Status Scale (EDSS) score. Conclusion: These findings suggested that IL-39 may play a pro-inflammatory role in the pathogenesis of NMOSD and correlate with disease severity.