Clinical characteristics of 153 Brazilian patients with neuromyelitis optica spectrum disorder (NMOSD)

Background: The 2015 criteria for diagnosing neuromyelitis optica spectrum disorder (NMOSD) have encouraged several groups across the world to report on their patients using these criteria. The disease typically manifests with severe relapses of optic neuritis, longitudinally extensive myelitis and/or brainstem syndromes, often leading to severe disability. Some patients are seropositive for antibodies against aquaporin-4 (AQP4), others are positive for anti-myelin oligodendrocyte glycoprotein (MOG), while a few are negative for both biomarkers. The disease is complex, and only now are specific therapeutic clinical trials being carried out The present study adds to the literature through detailed clinical data from 153 medical records of Brazilian patients. Methods: Retrospective assessment of medical records from nine specialized units in Brazil. Results: NMOSD was more prevalent in females (4.1:1), who had significantly fewer relapses than males (p = 0.007) but presented similar levels of disability over time. African ancestry was associated with higher levels of disability throughout the disease course (p < 0.001), although the number of relapses was similar to that observed in white patients. Concomitant autoimmune diseases were relatively rare in this population (6.5%). Positivity for anti-AQP4 antibodies was identified in 62% of the patients tested, while 3% presented anti-MOG antibodies. Anti-AQP4 antibodies were not associated to worse disease course. The last medical record showed that six patients had died and 13 were wheelchair-bound. Seventy percent of the patients did not respond to first-line therapy (azathioprine and/or corticosteroids), and five patients continued to relapse even after four different courses of treatment. Conclusion: The present study adds to the reports from other countries presenting original data on Brazilian patients diagnosed with NMOSD according to the 2015 criteria.