Secreted aminoacyl-tRNA synthetase-interacting multifunctional protein-1 (AIMP1) is a promising predictor for the severity of acute AQP4-IgG positive neuromyelitis optica spectrum disorder

•The study demonstrated that plasma AIMP1 levels were dramatically elevated in patients with acute AQP4-IgG+ NMOSD than in HCs.•High-dose intravenous methylprednisolone therapy significantly reduced the levels of AIMP1 in patients with acute AQP4-IgG+ NMOSD.•Plasma AIMP1 levels in clinically remission NMOSD patients decreased but were still higher than in HCs.•The plasma AIMP1 levels positively correlated with EDSS scores and negatively correlated with serum C3 concentrations in patients with acute AQP4-IgG+ NMOSD. Aminoacyl-tRNA synthetase complex interacting with multifunctional protein-1 (AIMP1) has been reported to carry pro-inflammatory properties and anti-angiogenesis effects. However, the exact role of AIMP1 in patients with NMOSD is not yet clear. Our objective was to investigate the relationship between plasma AIMP1 levels and disease severity in patients with AQP4-IgG+ NMOSD from North China based on the Expanded Disability Status Scale (EDSS) score. Plasma AIMP1 levels were measured using ELISA kits in 94 patients with AQP4-IgG+NMOSD (48 in the acute phase before high-dose intravenous methylprednisolone (IVMP) therapy, 21 in the acute phase after IVMP therapy, 25 in the clinical remission-phase)as well as 33 healthy controls (HCs). The disability function of NMOSD patients was evaluated using the EDSS score. Furthermore, the clinical characteristics of the patients were also evaluated, and laboratory tests were performed on blood samples. The plasma AIMP1 levels in AQP4-IgG+NMOSD patients with acute phase before IVMP therapy were significantly higher as compared to those in patients after the IVMP therapy (p