目的：探讨小剂量利妥昔单抗(rituximab, RTX)预防视神经脊髓炎谱系疾病(neuromyelitis optica spectrum disorder, NMOSD)复发的有效性和安全性。方法：采用前瞻性自身对照试验，选取2020年7月至2021年4月临床确诊为NMOSD的38例患者进行研究，给予小剂量RTX治疗。所有患者均进行病史采集、眼科检查和血清学指标检测，记录NMOSD年复发率(ARR)、最佳矫正视力(BCVA)、合并自身抗体情况和追加治疗的情况。视力检查采用Snellen视力表进行，并将结果转换为最小分辨角对数(logMAR)视力记录。随访至少12个月（17.29±2.2）个月，以末次随访为疗效判定时间点，比较治疗前后ARR、BCVA；分析复发与发病年龄、是否合并自身免疫抗体阳性和患自身免疫性疾病的关系。记录不良反应的发生率和追加治疗的时间。结果：共38例患者61眼纳入研究。其中男性4例，女性34例。发病年龄12~60岁，中位发病年龄23 (18~29.3)岁。病程10.0~265个月，中位病程65 (48.3~101.0)个月。治疗前logMAR矫正视力(1.15±0.13)，治疗后logMAR矫正视力(1.54±0.39)，比较差异无统计学意义(t=1.120，P=0.267)。治疗前ARR(1.50±0.86)次/年，治疗后ARR降低为(0.12±0.07)次/年，比较差异有统计学意义(t=8.304，P<0.001)。追加治疗时间为(6.4±2.3)月。随访期间3例患者复发，复发次数为 5次。 复发者与未复发者的发病年龄、合并免疫抗体阳性比例、合并自身免疫性疾病比例比较，差异均无统计学意义(均P>0.05)。38例患者中，出现输注不良反应7例，给予减慢RTX滴速及加用地塞米松5 mg治疗后均缓解，随访期间未见其他明显不良反应。结论：小剂量RTX可以有效清除B淋巴细胞，预防NMOSD复发，且安全性较好。

Objective: To evaluate the efficacy and safety of long-term treatment with low-dose rituximab for neuromyelitis optica spectrum disorders (NMOSD). Methods: A prospective self-control study. A total of 38 patients who were diagnosed with NMOSD from July 2020 to April 2021 were recruited for rituximab treatment. All patients collected medical history, ophthalmic examination and serological test. Recorded the annual recurrence rate (ARR), best corrected visual acuity (BCVA), combined autoantibodies and therapy times after the first treatment. The BCVA was examined using Snellen chart, and converted to logMAR. The patients were followed up at least 12(17.29±2.2) months, and the last follow-up was taken as the time point of efficacy evaluation. ARR and BCVA before and after treatment were compared. To analyze the relationship between relapse and age of onset, combination of autoimmune antibodies and autoimmune diseases. The incidence of side effects and duration of additional therapy were recorded. Results: A total of 38 NMOSD patients (4 male/34 female, 61 involved eyes) were included in this study. The ages of onset age were 12-60 years, the median onset age was 23 (18~29.3) years. Duration of disease was 10.0~265 months, the median duration was 65 (48.3~101.0) months. Before treatment, the mean BCVA was 1.15 ± 0.13 , the mean BCVA at last follow-up was 1.54 ± 0.39, which was no significant difference (t=1.120, P=0.267). The mean ARR before and after treatment were 1.50±0.86 and 0.12 ± 0.07, respectively, with significant difference (t=8.304, P<0.001). The mean reinfusion period was 6. 4±2.3 months. Five relapses in 3 patients were observed. There were no significant difference between relapsed patients and non-relapsed patients on onset age, with/without auto-immune antibody ratio, with/without auto-immune diseases ratio (all P>0.05). Of 38 patients, 7 patients had side effects, all patients who had side effects, slowing down the infusion speed of RTX or infusing 5 mg of dexamethasone could relieve the discomfort. Conclusions: Low-dose RTX can effectively clear B lymphocytes, prevent NMOSD recurrence and with good safety.