Neuromyelitis Optica Spectrum Disorder (NMOSD) is a rare autoimmune disease characterized by demyelination and axonal injury of the central nervous system. Serologic classification for aquaporin-4 immunoglobulin G (AQP4-IgG) and myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG) can be useful and have been associated with diverse outcomes.
To characterize NMOSD stratified by antibody serostatus (AQP4-IgG antibody positive, MOG-IgG antibody negative, and APQ4-IgG/MOG-IgG double negative) and evaluate predictors of disability outcomes.
This was a retrospective, single center study of 75 patients meeting NMOSD 2015 criteria who are seen and followed at a single center. AQP4-IgG and MOG-IgG antibodies were tested. The relationship between antibody status (AQP4-IgG+, MOG-IgG+) and double seronegative (DNeg) and DMT failure and Expanded Disability Status Scale (EDSS) was tested using multivariate linear regression (adjusted for age of onset, sex, race/ethnicity). DMT failure was defined as having to switch due to breakthrough disease on current DMT.
Most were female (76.7%), Hispanic (62.7%), with a median age of onset of 39.0 (SD±13.9) and disease duration of 8.0 (SD±7.5). More than 2/3 (69%) were on rituximab. Presentation with optic neuritis or myelitis varied by seropositive types (P-value<0.05). APQ4-IgG+ presented more likely with optic neuritis (44.5%) while DNeg were more likely to present with myelitis (87%). Disability also differed significantly between the groups (p-value<0.05). About 40% of AQP4IgG+ and DNeg patients had EDSS>=4 while all MOG-IgG patients had EDSS<4. Greater odds of DMT failure was observed with being MOG-IgG+ (OR 2.9 95% CI 0.86-10.22) compared to AQP4-IgG+. After controlling for age, sex, age at onset and DMT failure, MOG-IgG+ patients had lower disability (mean EDSS:1.6, p-value<0.01) compared to AQP4-IgG+ and DNeg patients (mean EDSS:3.6).
In this predominant Hispanic sample of NMOSD, we confirm that MOG-IgG+ serostatus is an important biomarker of treatment failure. Treatment approaches specific to NMOSD MOG-IgG+ are warranted.