Neuromyelitis optica spectrum disorders with and without associated autoimmune diseases.

OBJECTIVES: We aimed to determinate the frequency of this association and compare the features of neuromyelitis optica spectrum disorder (NMOSD) with and without associated autoimmune diseases (AD) in a Latin American (LATAM) population in clinical practice. METHODS: We retrospectively reviewed the medical records of patients with NMOSD according to the 2015 diagnostic criteria. Patients from Argentina (n=77), Brazil (n=46), and Venezuela (n=17) were enrolled and classified into two groups as follows: with AD or without AD. Clinical, paraclinical (including aquaporin-4 antibodies (AQP4-ab) status), magnetic resonance imaging (MRI), and prognosis data were analyzed and compared. Kaplan-Meier (KM) and the Nelson-Aalen estimator analyses were performed to estimate both time and the cumulative hazard risk of disability reaching an EDSS≥4; and time for the first recurrence. RESULTS: Out of 140 patients, 33 (23.5%) patients had associated an AD at presentation. The most frequent associated AD was Hashimoto disease (n=10) followed by lupus (n=7) and Sjogren's syndrome (n=6). However, rituximab use (42.4% vs. 21.5%, p=0.02), female gender (82.2% vs. 100%, p=0.006), corticospinal lesions on MRI (0% vs. 12.5%, p=0.01) at onset, and positivity for antinuclear antibodies (21.2% vs. 48.4%, p=0.03) were significantly associated with NMOSD patients with AD in comparison to NMOSD patients without AD. No differences were found in other clinical and paraclinical aspects between groups. KM and Nelson-Aalen estimator analyses did not show differences between groups. CONCLUSION: NMOSD patients associated with AD were observed in 23.5%. In addition, NMOSD patients with and without associated AD were similar in most evaluated features.

Brain magnetic resonance imaging features in multiple sclerosis and neuromyelitis optica spectrum disorders patients with or without aquaporin-4 antibody in a Latin American population.

INTRODUCTION: There is scarce evidence comparing the behavior in magnetic resonance (MRI) between positive and negative aquaporin-4 antibody neuromyelitis optica spectrum disorders (P-NMOSD and NNMOSD, respectively). The aim of this study was to describe and compare MRI features through a quantitative and qualitative analysis between P-NMOSD and NNMOSD patients in a cohort from Latin American (LATAM) patients. METHODS: We retrospectively reviewed the MRI and medical records of NMOSD patients as defined by the 2015 validated diagnostic criteria, and with at least 3 years of follow-up from disease onset (first symptom). We included patients from Argentina, Brazil and Venezuela. To be included, NMOSD patients must have had AQP4-ab status measured by a cell-based assay. Brain MRIs were obtained for each participant at disease onset and every 12 months for 3 years. Demographics, clinical and MRI variables (T2 lesion volume [T2LV], lesion distribution, cortical thickness [CT] and percentage of brain volume loss [PBVL]) were analyzed and compared between groups (P-NMOSD; NNMOSD) at disease onset and follow-up. A multiple sclerosis (MS) control group of patients was also included. RESULTS: We included 24 P-NMOSD, 15 NNMOSD and 35 MS patients. No differences in age, gender and follow-up time were observed between groups. Nor were differences found in lesion distribution at disease onset or in brain volumes during follow-up between P-NMOSD and NNMOSD patients (T2LV = 0.43, CT = 0.12, PBVL p = 0.45). Significant differences were observed in lesion distribution at disease onset, as well as in brain volumes during follow-up between NMOSD and MS (T2LV = p<0.001, CT = p<0.001, PBVL p = 0.01). CONCLUSION: Different MRI features were observed between MS and NMOSD. However, no quantitative nor qualitative differences were observed between P-NMOSD and NNMOSD, not allowing us to differentiate NMOSD conditions by MRI.

Central Nervous System Idiopathic Inflammatory Demyelinating Disorders in South Americans: A Descriptive, Multicenter, Cross-Sectional Study.

The idiopathic inflammatory demyelinating disease (IIDD) spectrum has been investigated among different populations, and the results have indicated a low relative frequency of neuromyelitis optica (NMO) among multiple sclerosis (MS) cases in whites (1.2%-1.5%), increasing in Mestizos (8%) and Africans (15.4%-27.5%) living in areas of low MS prevalence. South America (SA) was colonized by Europeans from the Iberian Peninsula, and their miscegenation with natives and Africans slaves resulted in significant racial mixing. The current study analyzed the IIDD spectrum in SA after accounting for the ethnic heterogeneity of its population. A cross-sectional multicenter study was performed. Only individuals followed in 2011 with a confirmed diagnosis of IIDD using new diagnostic criteria were considered eligible. Patients' demographic, clinical and laboratory data were collected. In all, 1,917 individuals from 22 MS centers were included (73.7% female, 63.0% white, 28.0% African, 7.0% Mestizo, and 0.2% Asian). The main disease categories and their associated frequencies were MS (76.9%), NMO (11.8%), other NMO syndromes (6.5%), CIS (3.5%), ADEM (1.0%), and acute encephalopathy (0.4%). Females predominated in all main categories. The white ethnicity also predominated, except in NMO. Except in ADEM, the disease onset occurred between 20 and 39 years old, early onset in 8.2% of all cases, and late onset occurred in 8.9%. The long-term morbidity after a mean disease time of 9.28±7.7 years was characterized by mild disability in all categories except in NMO, which was scored as moderate. Disease time among those with MS was positively correlated with the expanded disability status scale (EDSS) score (r=0.374; p=<0.001). This correlation was not observed in people with NMO or those with other NMO spectrum disorders (NMOSDs). Among patients with NMO, 83.2% showed a relapsing-remitting course, and 16.8% showed a monophasic course. The NMO-IgG antibody tested using indirect immunofluorescence (IIF) with a composite substrate of mouse tissues in 200 NMOSD cases was positive in people with NMO (95/162; 58.6%), longitudinally extensive transverse myelitis (10/30; 33.3%) and bilateral or recurrent optic neuritis (8/8; 100%). No association of NMO-IgG antibody positivity was found with gender, age at onset, ethnicity, early or late onset forms, disease course, or long-term severe disability. The relative frequency of NMO among relapsing-remitting MS (RRMS) + NMO cases in SA was 14.0%. Despite the high degree of miscegenation found in SA, MS affects three quarters of all patients with IIDD, mainly white young women who share similar clinical characteristics to those in Western populations in the northern hemisphere, with the exception of ethnicity; approximately one-third of all cases occur among non-white individuals. At the last assessment, the majority of RRMS patients showed mild disability, and the risk for secondary progression was significantly superior among those of African ethnicity. NMO comprises 11.8% of all IIDD cases in SA, affecting mostly young African-Brazilian women, evolving with a recurrent course and causing moderate or severe disability in both ethnic groups. The South-North gradient with increasing NMO and non-white individuals from Argentina, Paraguay, Brazil and Venezuela confirmed previous studies showing a higher frequency of NMO among non-white populations.