Association of neutrophil-to-lymphocyte ratio (NLR) with the prognosis of first attack neuromyelitis optica spectrum disorder (NMOSD): a retrospective cohort study

Background To investigate the relationship between the neutrophil-to-lymphocyte ratio (NLR) and prognosis after the first attack of optic neuromyelitis optica spectrum disorder (NMOSD). Methods In this retrospective study, we included the medical records of 324 patients with first episode NMOSD and collected data on clinical parameters. Follow-up extended disability status scale (EDSS) score and relapse rate were analyzed using logistic regression models to determine the independent effect of NLR on outcomes; receiver operating characteristic (ROC) curves were applied to analyze the predictive value of NLR for the prognosis of NMOSD. Interaction and stratification analyses were used to explore the association between NLR and prognosis of patients with NMOSD, and Kaplan-Meier analysis was used to investigate the relationship between NLR and outcome. The association between NLR level with relapse rate and poor recovery was assessed by a Cox regression analysis. Results Patients in the high-NLR group had significantly higher EDSS scores and relapse rates at follow-up (both, P < 0.001) than did those in the low-NLR group. Univariate analysis showed revealed that NLR was significantly associated with relapse (odds ratio [OR] = 1.28, 95% confidence interval [CI]: 1.16-1.41, P < 0.001) and poor recovery (OR = 1.32, 95% CI: 1.20-1.46, P < 0.001), and these associations remained significant, even after multifactorial analysis (OR = 1.33, 95% CI: 1.11-1.59, P = 0.002; OR = 1.23, 95% CI: 1.06-1.43, P = 0.007, respectively). Stratified analysis showed that sex, platelet-to-lymphocyte ratio (PLR) level, and lymphocyte-to-monocyte technical ratio (LMR) level were strongly associated with relapse owing to elevated NLR; Kaplan-Meier survival curve analysis showed that the median time to relapse was significantly lower in the high-NLR group than in the low-NLR group (P < 0.001). A multivariate analysis showed a significant relationship between NLR level with relapse (HR = 1.07, 95%CI: 1.03-1.10, P = 0.001) and poor recovery (HR = 1.08, 95%CI: 1.04-1.11, P = 0.001). Conclusions NLR may be used as a prognostic indicator for first onset NMOSD, and a high NLR may be significantly associated with high relapse rates and poor recovery.