Evaluation of CD3+CD56+ NKT and CD19+ B Cells in Assessing the Relapse of Neuromyelitis Optica Spectrum Disorder Patients Treated With Rituximab

ABSTRACT Aim The purpose of this study was to explore the value of pre‐treatment levels of CD3+CD56+ NKT cells and CD19+ B cells in evaluating the relapse of patients with neuromyelitis optica spectrum disorders (NMOSD) treated with rituximab. Methods A total of 166 NMOSD patients admitted to our hospital from January 2021 to August 2022 were included in this study. All patients received rituximab and were followed up for 1 year. Based on their relapse status, patients were categorized into a relapse group ( n = 10) and a non‐relapse group ( n = 156). Peripheral venous blood samples were collected, and the pre‐treatment levels of CD3+CD56+ NKT and CD19+ B cells were measured using flow cytometry. Logistic regression analysis was used to identify factors influencing relapse, and receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive value of these cells for relapse. Results The relapse group had significantly lower levels of CD3+CD56+ NKT cells and higher levels of CD19+ B cells compared to the non‐relapse group ( p < 0.05). Multivariate analysis confirmed that lower pre‐treatment CD3+CD56+ NKT cell levels (OR = 1.549, 95% CI: 1.068–2.199; p = 0.001) and higher CD19+ B cell levels (OR = 1.272, 95% CI: 1.039–1.758; p = 0.002) were potential independent predictors of relapse. ROC curve analysis showed that the combined model yielded a modest predictive value (AUC = 0.652, p < 0.05), which was statistically superior to that of either biomarker alone. During follow‐up, rituximab was generally well‐tolerated, with infusion‐related reactions (18.1%) and infections (11.4%) being the most common adverse events. Conclusion Pre‐treatment levels of CD3+CD56+ NKT cells and CD19+ B cells are potential markers for evaluating the risk of relapse in NMOSD patients treated with rituximab, although their predictive accuracy is modest.