Liang J, Liu J, Fan R, et al. - By analyzing case data obtained from 97 acute-phase neuromyelitis optica spectrum disorder (NMOSD) patients and 39 stable-phase NMOSD patients, researchers analyzed alterations in plasma homocysteine (Hcy) levels and examined the link between Hcy levels and inflammatory/immune/cerebrospinal fluid parameters in patients with NMOSD. They categorized the patients in the acute phase into 2 groups depending on the EDSS score with cutoff equal to 4. They found that acute-phase and stable-phase NMOSD patients did not significantly differ in terms of Hcy levels. Acute-phase NMOSD patients with EDSS score ≥ 4 exhibited significantly higher Hcy and erythrocyte sedimentation rate (ESR) levels. Besides, a positive correlation of EDSS with Hcy level, ESR, 1/aquaporin-4 titer, as well as a negative correlation of Hcy level with IgM was observed in acute-phase NMOSD patients. The potential of elevated plasma Hcy to influence the pathogenesis or progression of NMOSD was suggested based on these findings.