Treatment Of Neuromyelitis Optica Spectrum Disorder Research Articles

Angiotensin AT2 receptor–induced interleukin-10 attenuates neuromyelitis optica spectrum disorder–like pathology

Background: Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing inflammatory central nervous system (CNS) disease for which there is no cure. Immunoglobulin G autoantibodies specific for the water channel aquaporin-4 are a serum biomarker, believed to induce complement-dependent astrocyte damage with secondary demyelination. Objective: To investigate the effect of angiotensin AT2 receptor (AT2R) stimulation on NMOSD-like pathology and its underlying mechanism. Methods: NMOSD-like pathology was induced in mice by intracerebral injection of immunoglobulin-G isolated from NMOSD patient serum, with complement. This mouse model produces the characteristic histological features of NMOSD. A specific AT2R agonist, Compound 21 (C21), was given intracerebrally at day 0 and by intrathecal injection at day 2. Results: Loss of aquaporin-4 and glial fibrillary acidic protein was attenuated by treatment with C21. Administration of C21 induced mRNA for interleukin-10 in the brain. NMOSD-like pathology was exacerbated in interleukin-10-deficient mice, suggesting a protective role. C21 treatment did not attenuate NMOSD-like pathology in interleukin-10-deficient mice, indicating that the protective effect of AT2R stimulation was dependent on interleukin-10. Conclusion: Our findings identify AT2R as a novel potential therapeutic target for the treatment of NMOSD. Interleukin-10 signaling is an essential part of the protective mechanism counteracting NMOSD pathology.

Neuromyelitis optica spectrum disorders: Emerging therapies

AbstractNeuromyelitis optica or neuromyelitis optica spectrum disorders (NMOSD) are autoimmune diseases associated with a disease‐specific autoantibody directed against the water channel protein aquaporin‐4. While almost all patients with NMOSD show a relapsing‐remitting course, just 2% of patients present with a progressive course, suggesting that preventing acute attacks can lead to stable remission and avoid progression of the condition. Standard immunotherapy, immunosuppressive agents, and corticosteroids can prevent acute attacks and maintain remission in the majority of patients with NMOSD. However, there is a strong need for alternative options for patients who are refractory to standard treatments. Emerging therapies targeting specific molecules related to the pathogenicity of NMOSD are currently being developed. In addition to standard intravenous high‐dose corticosteroid and plasma exchange/plasmapheresis, therapies targeted at inhibiting granulocytes, complement, and vascular endothelial growth factor are anticipated for acute attacks. With regard to preventive treatment of NMOSD, randomized clinical trials using monoclonal immunoglobulin G antibody targeting CD19 and CD20 on B cells, interleukin‐6, and complement protein C5 are underway. There are many preclinical therapeutic agents that target aquaporin‐4 and the pathogenic anti‐aquaporin‐4 antibody itself: complement inhibitor and T helper 17 cells based on the specific NMOSD pathology. The future goal of immunotherapies for NMOSD would be to select suitable therapies for the patient's pathological condition among off‐target and molecular‐target agents.

Rituximab in Neuromyelitis Optica Spectrum Disorders: Our Experience.

Background:Neuromyelitis optica (NMO) is an inflammatory demyelinating central nervous system disease, with recurrent attacks of severe bilateral optic neuritis and longitudinally extensive transverse myelitis. Aggressive immunosuppression is essential to prevent clinical relapses and permanent disability. Rituximab, a monoclonal antibody to CD20, has been found effective in several reports and small uncontrolled studies. There is a paucity of data regarding its use in Indian patients.Objectives:The aim of this study was to report the results of rituximab treatment in NMO spectrum disorders (NMOSDs) in the Indian scenario.Methods:This study is a retrospective, observational study including 13 NMOSD patients treated with rituximab. After initial therapy in the acute episode with IV methylprednisolone and if needed plasma exchange, therapy was initiated as a cycle of intravenous rituximab, two doses 2 weeks apart of 1 g each. Subsequent cycles were advised at intervals of every 6 months. The primary outcome measure was annualized relapse rate (ARR), defined as a number of clinical attacks per year. Clinical adverse events were recorded throughout the study.Results:In the study, mean ARR reduced from 2.61 to 0.09 after therapy (P = 0.000685). Of 13 patients, 8 (61.54%) were completely relapse free after starting treatment with rituximab. Treatment was well tolerated and no serious adverse events were noted.Conclusions:The treatment of NMOSDs with rituximab in Indian patients reduces the frequency of relapses and is well tolerated.