Pediatric Multiple Sclerosis in Rio de Janeiro: Secondary Progression and Disability.

BACKGROUND: The onset of multiple sclerosis (MS) in 2% to 10% of cases occurs prior to 18 years of age. Early age onset appears to affect some aspects of multiple sclerosis. The objective of our study was to evaluate the prevalence, the clinical and demographic characteristics, and the disease progression in a sample of pediatric multiple sclerosis patients from a mixed population. METHODS: In a cross-sectional design, the prevalence, demographic characteristics, and initial clinical forms were compared between 75 cases of pediatric multiple sclerosis (PMS) and 689 adults with MS. Sixty-five PMS patients with complete data and 260 randomly selected adults with relapsing-remitting multiple sclerosis were compared. A Kaplan-Meier analysis was conducted to compare the age at and time to Expanded Disability Status Scale (EDSS) 3, EDSS 6, and secondary progressive multiple sclerosis (SPMS). RESULTS: A total of 9.8% of all MS cases with available data were PMS. All cases of PMS consisted of relapsing-remitting multiple sclerosis. Brazilians of African descent comprised 34.6% of the sample, and the female-to-male ratio was 2.4:1. At the first attack, motor alterations were more common. Benign forms were more common in PMS (84.6% versus 62.2%). Fewer PMS patients reached EDSS 6 (11.6% versus 25.4%) (P = 0.0017) and SPMS (11.1% versus 28.1%) (P = 0.005). PMS patients took longer to reach EDSS 3 (P = 0.017), EDSS 6 (P = 0.001), and SPMS (P < 0.001); however, they reached EDSS 3 earlier (P < 0.001). CONCLUSIONS: In this mixed cohort, the prevalence of PMS was similar to that reported in other studies, and the pediatric patients had a more benign course than adults with MS.

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.

African ancestry is a predictor factor to secondary progression in clinical course of multiple sclerosis.

Background. Studies on the clinical course of multiple sclerosis have indicated that certain initial clinical factors are predictive of disease progression. Regions with a low prevalence for disease, which have environmental and genetic factors that differ from areas of high prevalence, lack studies on the progressive course and disabling characteristics of the disease. Objective. To analyse the long-term evolution to the progressive phase of the relapsing-remitting multiple sclerosis and its prognosis factors in mixed population. Methods. We performed a survival study and logistic regression to examine the influence of demographic and initial clinical factors on disease progression. Among 553 relapsing-remitting patients assisted at a Brazilian reference centre for multiple sclerosis, we reviewed the medical records of 150 patients who had a disease for ten or more years. Results. African ancestry was a factor that conferred more risk for secondary progression followed by age at the onset of the disease and the number of relapses in the year after diagnosis. A greater understanding of the influence of ancestry on prognosis serves to stimulate genetics and pharmacogenomics research and may clarify the poorly understood neurodegenerative progression of MS.

Differences in the progression of primary progressive multiple sclerosis in Brazilians of African descent versus white Brazilian patients.

Recent studies have suggested faster clinical progression and greater disability in multiple sclerosis patients of African descent. This study analysed the effect of ethnicity on progression and disability. Sixty-five patients with primary progressive multiple sclerosis were selected and classified as being of African descent or white. Time from onset of the disease until reaching Expanded Disability Status Scale grades 3, 6, and 8 was assessed, as well as irreversible disability (Expanded Disability Status Scale grade maintained for >or=6 months). In the African descent group, the median time to reach Expanded Disability Status Scale 3 was 1 year shorter (1 year vs 2 years, p= 0.02), and to reach Expanded Disability Status Scale 6 was 2 years shorter (3 years vs 5 years, p= 0.01) than in the group of white patients. According to the Kaplan-Meier survival curves, patients of African descent reached every disability stage faster than white patients (p= 0.03, p = 0.04, and p = 0.03, respectively, for Expanded Disability Status Scale grades 3, 6, and 8). As in United States and European patients of African descent, the more severe and faster progression of multiple sclerosis seen in Brazilian primary progressive multiple sclerosis patients of African descent suggests a possibly greater effect of ethnicity rather than environment on the progression of multiple sclerosis.