Neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein-antibody-associated disease have distinct progressions of disability, with the latter being associated with a less severe clinical course of the disease, according to the results of a combined retrospective and prospective study.
Neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are autoimmune conditions that predominantly affect the spinal cord and optic nerve. NMOSD is characterized by the presence of aquaporin-4 immunoglobulin G (AQP4-IgG) in up to 80% of patients, and myelin oligodendrocyte glycoprotein (MOG) autoantibodies in a subgroup of seronegative patients.
This study assessed the time to disability milestones and relapse rates in patients with NMOSD, AQP4-IgG+ NMOSD, and seronegative NMOSD in the German neuromyelitis optica study group (NEMOS). The study findings are published in the journal Annals of Neurology.
Baseline Characteristics
The study included a total of 483 participants, with 298 AQP4-IgG+ NMOSD patients, 52 seronegative NMOSD patients, and 133 MOGAD patients. The mean follow-up time was 10 ± 8.9 years for AQP4-IgG+ NMOSD patients, 9.1 ± 5.9 years for seronegative NMOSD patients, and 7.4 ± 8.6 years for MOGAD patients. The female population was estimated to be 90.6% in the AQP4-IgG+ NMOSD group, 42.3% in the seronegative NMOSD group, and 57.1% in the MOGAD group. The mean age of AQP4-IgG+ NMOSD, seronegative NMOSD, and MOGAD patients was 43.1 ± 16.3 years, 35.7 ± 12.4 years, and 33.6 ± 13.6 years, respectively.
Disability Milestones in NMOSD and MOGAD
Compared to MOGAD patients, seropositive and seronegative NMOSD patients demonstrated a shorter median time to attain disability milestones. Compared to seronegative NMOSD, AQP4-IgG+ NMOSD required a greater number of attacks for the accumulation of disability, indicated by the Expanded Disability Scale Score (EDSS) score of 3. A median of eight attacks was observed in the MOGAD group before attaining the same EDSS score. The risk factors for disability progression included myelitis as the first manifestation and first attack at the age of greater than 50 years.
Mortality in Neuromyelitis Optica Spectrum Disorder
Of the total, 18 patients in the study cohort died after a mean disease duration of 9 years. Except for three patients, the patients who died were older than 40 years of age at the time of NMOSD diagnosis. The median age of these individuals was 51.5 (6–76) years, and they had a history of a minimum of one immunosuppressive medication during the disease course. The deaths were likely to be associated with complications resulting from immunosuppressive treatment and neurological disability.
Source:
Duchow, A., Bellmann‐Strobl, J., Friede, T., Aktaş, O., Angstwurm, K., Ayzenberg, I., Berthele, A., Dawin, E., Engels, D., Fischer, K., Flaskamp, M., Giglhuber, K., Grothe, M., Havla, J., Hümmert, M. W., Jarius, S., Kaste, M., Kern, P., Kleiter, I., . . . Häußler, V. (2023). Time to disability milestones and annualized relapse rates in NMOSD and MOGAD. Annals of Neurology. https://doi.org/10.1002/ana.26858
