B cell depleting therapy for multiple sclerosis overlapping with neuromyelitis optica spectrum disorder

B Cells in Neuroinflammation: New Perspectives and Mechanistic Insights

In recent years, the role of B cells in neurological disorders has substantially expanded our perspectives on mechanisms of neuroinflammation. The success of B cell-depleting therapies in patients with CNS diseases such as neuromyelitis optica and multiple sclerosis has highlighted the importance of neuroimmune crosstalk in inflammatory processes. While B cells are essential for the adaptive immune system and antibody production, they are also major contributors of pro- and anti-inflammatory cytokine responses in a number of inflammatory diseases. B cells can contribute to neurological diseases through peripheral immune mechanisms, including production of cytokines and antibodies, or through CNS mechanisms following compartmentalization. Emerging evidence suggests that aberrant pro- or anti-inflammatory B cell populations contribute to neurological processes, including glial activation, which has been implicated in the pathogenesis of several neurodegenerative diseases. In this review, we summarize recent findings on B cell involvement in neuroinflammatory diseases and discuss evidence to support pathogenic immunomodulatory functions of B cells in neurological disorders, highlighting the importance of B cell-directed therapies.

Low-Dose Mycophenolate Mofetil for Treatment of Neuromyelitis Optica Spectrum Disorders: A Prospective Multicenter Study in South China

Objective: To evaluate the efficacy and safety of low-dose mycophenolate mofetil (MMF, 1,000 mg/day) treatment of neuromyelitis optica spectrum disorders (NMOSDs).

Methods: This study was a multicenter, open, prospective, follow-up clinical trial. The data include retrospective clinical data from the pretreatment phase and prospective data from the post-treatment phase. From September 2014 to February 2017, NMOSD patients seropositive for aquaporin 4-IgG (AQP4-IgG) were treated with low-dose MMF.

Results: Ninety NMOSD patients were treated with MMF for a median duration of 18 months (range 6–40 months). The median annual recurrence rate (ARR) decreased from 1.02 before treatment to 0 (P < 0.0001) after treatment, and the Expanded Disability Status Scale (EDSS) score decreased from 4 to 3 (P < 0.0001). The EDSS score was significantly lower (P = 0.038) after the first 90 days of treatment. The serum AQP4-IgG titer decreased in 50 cases (63%). The median Simple McGill pain score (SF-MPQ) was reduced in 65 patients (88%) with myelitis from 17 (range 0–35) to 11 (range 0–34) after treatment (P < 0.0001). The median Hauser walking index (Hauser Walk Rating Scale) was reduced from 2 (range 1–9) before treatment to 1 (range 0–7) after treatment (P < 0.0001). Adverse events were documented in 43% of the patients, and eight patients discontinued MMF due to intolerable adverse events. Fourteen (16%) of the total patients discontinued MMF after our last follow-up for various reasons and switched to azathioprine or rituximab.

Conclusion: Low-dose MMF reduced clinical relapse and disability in NMOSD patients in South China. However, some patients still suffered from adverse events at this dosage.

Clinical Trial Registration: www.ClinicalTrials.gov, identifier : NCT02809079.