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Induction of Paralysis and Visual System Injury in Mice by T Cells Specific for Neuromyelitis Optica Autoantigen Aquaporin-4
Published on: August 21, 2017
Double-Negative Neuromyelitis Optica Spectrum Disorder: A Systematic Review and Meta-Analysis
Antonio Malvaso1,2, Francesca Bovis3, Giacomo Greco1,4
1Department of Brain and Behavioral Sciences, University of Pavia, Italy.
Background And Objectives:
Neuromyelitis optica spectrum disorder (NMOSD) is a severe condition usually associated with aquaporin-4 (AQP4) antibodies. A clinical presentation suggestive of NMOSD can also be associated with myelin oligodendrocyte glycoprotein (MOG) antibodies (MOGAD). NMOSD can be diagnosed in the absence of autoantibodies (double-negative NMOSD [DN-NMOSD]), but this subgroup has been poorly investigated. We conducted a systematic review and meta-analysis to define the clinical spectrum, prognosis, and treatment response in DN-NMOSD vs AQP4-NMOSD/MOGAD.
Methods:
We searched on PubMed, Scopus, Embase, Google Scholar, Cochrane Library, and ClinicalTrials.gov databases of studies on patients fulfilling inclusion criteria. Patient characteristics, outcome measures, and treatment regimens were extracted.
Results:
We included 41 of 1,027 articles screened and analyzed 671 patients with DN-NMOSD (median age 38.6 years [range IQR: 32.5-42.85]; female-to-male ratio 1.5:1; median follow-up 44.4 months [range 1-600]), 73.6% of which relapsed. In the meta-analysis, mean annualized relapse rate (ARR) was higher, albeit not significantly, in DN-NMOSD (1.08; 95% CI 0.73-1.43) vs AQP4-NMOSD (0.84; 95% CI 0.45-1.23) and MOGAD (0.61; 95% CI 0.39-0.83, p = 0.08). Administration of maintenance immunosuppression in DN-NMOSD led to a significant ARR reduction (pooled rate ratio 0.19, 95% CI 0.07-0.49; p = 0.001), with high heterogeneity (I2 = 90%, p < 0.0001). In meta-regression, no covariates were associated with ARR reduction, including the administration of specific drugs (rituximab, p = 0.288; azathioprine, p = 0.291; mycophenolate, p = 0.918). The pooled mean difference in pre‑ and post‑maintenance treatment Expanded Disability Status Scale values indicated a significant change in disability in MOGAD (-0.93, 95% CI -1.67 to -0.19, p = 0.02) but not in AQP4-NMOSD (-0.62, 95% CI -1.85 to 0.61, p = 0.27) or DN-NMOSD (-0.52 (95% CI -1.30 to 0.25, p = 0.16).
Discussion:
DN-NMOSD is a heterogenous, severe and highly relapsing disease, where attacks lead to irreversible dysfunction. The administration of maintenance immunotherapy reduces the relapse risk and should be considered early to prevent further disability.
