Microglial/macrophage activation in the cerebrospinal fluid of neuromyelitis optica spectrum disorders

The aims of this pilot study were to investigate the levels of biomarkers of microglial/macrophage activation-YKL-40, sCD163, and sCD14-in patients with neuromyelitis optica spectrum disorder (NMOSD) and determine the possible associations between these biomarkers and Expanded Disability Status Scale (EDSS) scores.We measured the levels of three microglia-/macrophage-related proteins (YKL-40, soluble CD163, and soluble CD14) in cerebrospinal fluid (CSF) using enzyme-linked immunosorbent assays. In addition, patients' neurological disability levels were assessed using EDSS scores.NMOSD patients had significantly higher CSF levels of YKL-40(210.52 ± 161.62 for NMOSD and 63.18 ± 9.22 for control), sCD163 (87.23 ± 56.85 for NMOSD and 58.14 ± 7.66 for control), and sCD14 (68.22 ± 24.11 for NMOSD and 55.75 ± 9.48 for control) compared with controls. Furthermore, these biomarker levels were positively correlated with EDSS scores in patients with NMOSD (r = 0.303, p = .002 for YKL-40; r = 0310, p = .001 for sCD14; r = 0.250, p = .011 for sCD163), but not in patients with multiple sclerosis or glial fibrillary acidic protein astrocytopathy.Our findings suggest that microglial/macrophage activation may be implicated in the pathogenesis of NMOSD.