Long-term safety and efficacy of Eculizumab in Aquaporin-4 IgG-positive NMOSD

Objective During PREVENT (NCT01892345), eculizumab significantly reduced relapse risk versus placebo in patients with aquaporin-4 immunoglobulin G-positive neuromyelitis optica spectrum disorder (AQP4-IgG+ NMOSD). We report an interim analysis of PREVENT's ongoing open-label extension (OLE; NCT02003144) evaluating eculizumab's long-term safety and efficacy. Methods Patients who completed PREVENT could enroll in the OLE to receive eculizumab (maintenance dose = 1,200 mg/2 weeks, after a blinded induction phase). Safety and efficacy data from PREVENT and its OLE (interim data cut, July 31, 2019) were combined for this analysis. Results Across PREVENT and the OLE, 137 patients received eculizumab and were monitored for a median (range) of 133.3 weeks (5.1–276.9 weeks), for a combined total of 362.3 patient-years (PY). Treatment-related adverse event (AE) and serious adverse event (SAE) rates were 183.5 in 100 PY and 8.6 in 100 PY, respectively. Serious infection rates were 10.2 in 100 PY in eculizumab-treated patients versus 15.1 in 100 PY in the PREVENT placebo group. No patient developed a meningococcal infection. At 192 weeks (3.7 years), 94.4% (95% confidence interval [CI], 88.6–97.3) of patients remained adjudicated relapse-free. The adjudicated annualized relapse rate was 0.025 (95% CI = 0.013–0.048) in all eculizumab-treated patients versus 0.350 (95% CI = 0.199–0.616) in the PREVENT placebo group. During the OLE, 37% of patients (44 of 119 patients) stopped or decreased background immunosuppressive therapy use. Interpretation This analysis demonstrates that eculizumab's long-term safety profile in NMOSD is consistent with its established profile across other indications. This analysis also demonstrated the sustained ability of long-term eculizumab treatment to reduce relapse risk in patients with AQP4-IgG+ NMOSD. ANN NEUROL 2021;89:1088–109

Case 34-2011: a man with memory loss and partial seizures

Letter to the EditorHeidi N. Beadnall, Michelle Kiley, Timothy J. Kleini

Exosomal microRNA signatures in multiple sclerosis reflect disease status

Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). There is currently no single definitive test for MS. Circulating exosomes represent promising candidate biomarkers for a host of human diseases. Exosomes contain RNA, DNA, and proteins, can cross the blood-brain barrier, and are secreted from almost all cell types including cells of the CNS. We hypothesized that serum exosomal miRNAs could present a useful blood-based assay for MS disease detection and monitoring. Exosome-associated microRNAs in serum samples from MS patients (n = 25) and matched healthy controls (n = 11) were profiled using small RNA next generation sequencing. We identified differentially expressed exosomal miRNAs in both relapsing-remitting MS (RRMS) (miR-15b-5p, miR-451a, miR-30b-5p, miR-342-3p) and progressive MS patient sera (miR-127-3p, miR-370-3p, miR-409-3p, miR-432-5p) in relation to controls. Critically, we identified a group of nine miRNAs (miR-15b-5p, miR-23a-3p, miR-223-3p, miR-374a-5p, miR-30b-5p, miR-433-3p, miR-485-3p, miR-342-3p, miR-432-5p) that distinguished relapsing-remitting from progressive disease. Eight out of nine miRNAs were validated in an independent group (n = 11) of progressive MS cases. This is the first demonstration that microRNAs associated with circulating exosomes are informative biomarkers not only for the diagnosis of MS, but in predicting disease subtype with a high degree of accuracy

The neuro-otology of Susac syndrome

Objective: We characterised the clinical and neuro-otological characteristics of patients with Susac syndrome. Methods: The medical records of 30 patients with Susac syndrome were reviewed for details of their clinical presentation and course, neuro-otological symptoms, investigation results including audiology and vestibular function tests, treatment and outcomes. Results: Our findings demonstrate that 29 of our 30 patients with Susac syndrome developed neuro-otological symptoms such as hearing loss, disequilibrium, tinnitus or vertigo during their disease course. Hearing loss was the most common neuro-otological symptom occurring in 93% of patients. A rising configuration of low-frequency greater than the high-frequency sensorineural hearing loss was the most characteristic finding on audiological testing (37% of reviewed audiograms). Disproportionately poor speech discrimination was identified in 20% of cases, and one case demonstrated a retrocochlear pattern on electrophysiological testing. Four patients required hearing aids and a further two patients required a cochlear implant due to severe hearing loss. Two out of two treated patients had improvements in hearing after the prompt administration of corticosteroids, indicating the potential for recoverable hearing loss if relapses are treated early. Effects on vestibular function were variable in ten patients who were tested, with most showing preservation of function despite significant hearing loss. Conclusions: Neuro-otological symptoms in Susac syndrome are almost universal. In the correct clinical context, a rising configuration of low to high-frequency sensorineural hearing loss should prompt consideration of Susac syndrome. Treatment of inner ear symptoms in Susac syndrome requires further research as early immunotherapy may be beneficial

Characterization of the human myelin oligodendrocyte glycoprotein antibody response in demyelination

Over recent years, human autoantibodies targeting myelin oligodendrocyte glycoprotein (MOG Ab) have been associated with monophasic and relapsing central nervous system demyelination involving the optic nerves, spinal cord, and brain. While the clinical relevance of MOG Ab detection is becoming increasingly clear as therapeutic and prognostic differences from multiple sclerosis are acknowledged, an in-depth characterization of human MOG Ab is required to answer key challenges in patient diagnosis, treatment, and prognosis. Herein, we investigated the epitope, binding sensitivity, and affinity of MOG Ab in a cohort of 139 and 148 MOG antibody-seropositive children and adults (n = 287 patients at baseline, 130 longitudinal samples, and 22 cerebrospinal fluid samples). MOG extracellular domain was also immobilized to determine the affinity of MOG Ab. MOG Ab response was of immunoglobulin G1 isotype, and was of peripheral rather than intrathecal origin. High affinity MOG Ab were detected in 15% paediatric and 18% adult sera. More than 75% of paediatric and adult MOG Ab targeted a dominant extracellular antigenic region around Proline42. MOG Ab titers fluctuated over the progression of disease, but affinity and reactivity to Proline42 remained stable. Adults with a relapsing course intrinsically presented with a reduced immunoreactivity to Proline42 and had a more diverse MOG Ab response, a feature that may be harnessed for predicting relapse. Higher titers of MOG Ab were observed in more severe phenotypes and during active disease, supporting the pathogenic role of MOG Ab. Loss of MOG Ab seropositivity was observed upon conformational changes to MOG, and this greatly impacted the sensitivity of the detection of relapsing disorders, largely considered as more severe. Careful consideration of the binding characteristics of autoantigens should be taken into account when detecting disease-relevant autoantibodies

Neurological immunotherapy in the era of COVID-19 — looking for consensus in the literature

The coronavirus disease 2019 (COVID-19) pandemic is concerning for patients with neuroimmunological diseases who are receiving immunotherapy. Uncertainty remains about whether immunotherapies increase the risk of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or increase the risk of severe disease and death upon infection. National and international societies have developed guidelines and statements, but consensus does not exist in several areas. In this Review, we attempt to clarify where consensus exists and where uncertainty remains to inform management approaches based on the first principles of neuroimmunology. We identified key questions that have been addressed in the literature and collated the recommendations to generate a consensus calculation in a Delphi-like approach to summarize the information. We summarize the international recommendations, discuss them in light of the first available data from patients with COVID-19 receiving immunotherapy and provide an overview of management approaches in the COVID-19 era. We stress the principles of medicine in general and neuroimmunology in particular because, although the risk of viral infection has become more relevant, most of the considerations apply to the general management of neurological immunotherapy. We also give special consideration to immunosuppressive treatment and cell-depleting therapies that might increase susceptibility to SARS-CoV-2 infection but reduce the risk of severe COVID-19