Epidemiology of neuromyelitis optica in Latin America

Abstract

A major development over the past two decades was the recognition of recurrent neuromyelitis optica (NMO) as a particular central nervous system disorder different from multiple sclerosis (MS). Here we reviewed the epidemiology of NMO in Latin America (LATAM). A predominance of a mixed population is found in this region. Recurrent NMO in black women was described in the Caribbean Islands and in Rio de Janeiro. The prevalence of NMO in LATAM varied from 0.37/100,000 (Volta Redonda city) to 4.2/100,000 inhabitants (Caribbean Islands). NMO differs significantly from MS with respect to gender, ethnicity, morbidity and genetic susceptibility. An association of the HLA DRB1*03 alleles with NMO was described in the French Antilles, Ribeirão Preto, Rio de Janeiro and Mexico. It is not common to find familial forms of NMO. NMO represents 11.8% of all inflammatory idiopathic diseases in South America (SA). In SA, the highest frequency of NMO occurs in African Brazilian young women. The overall relative frequency of NMO among MS cases in this region was 14%, decreasing following a north-south gradient, which parallels the percentage of nonwhite people.

Native American ancestry significantly contributes to neuromyelitis optica susceptibility in the admixed Mexican population

“…Notably, local ancestry analyses revealed that all HLA alleles most associated with NMO risk and protection in the present study were predominantly inferred as of Native American ancestry. This is consistent with our finding of a higher proportion of NAT ancestry in NMO cases as compared to controls, and with epidemiological data suggesting that NMO is more prevalent in non-European populations [9][10][11] . To our knowledge there is only one previous study analyzing local ancestry of demyelinating diseases, where HLA alleles DRB1*16:02 and DRB1*14:02 were inferred as of Native American ancestry in Hispanics 43 , also in consistency with our local ancestry findings.…”

“…Interestingly, the relative frequency of NMO (estimated as the ratio of NMO/(MS + NMO) cases) has been found to decrease gradually in South America from North (Venezuela) to South (Argentina). Because ethnicity also changes gradually from North to South in this region, with the proportion of European individuals being lower in Venezuela and higher in Argentina, the authors suggested that ethnic origin influences NMO frequency in Latin America 10 . To date there are no population-based studies of the prevalence of NMO in Mexico, and there is a single study estimating NMO prevalence at 1.3 per 100,000 inhabitants based on the NMO/(MS + NMO) relative frequency at a referral center in Mexico City 12 .…”

AQP4-IgG and MOG-IgG Related Optic Neuritis—Prevalence, Optical Coherence Tomography Findings, and Visual Outcomes: A Systematic Review and Meta-Analysis

“…A noteworthy exception to our finding of overall lower seroprevalence of AQP4-IgG seropositivity in non-Asian populations was the study by Carnero-Contentti et al ( 39 ), which enrolled patients from Buenos Aires, Argentina, and reported an AQP4-IgG seroprevalence of 30% among patients with ON ( 39 ). This finding is unexpected, given evidence supporting that the relative frequency of NMO vs. MS in Buenos Aires is low, and similar to that observed in Caucasian populations ( 91 ). Notably, this study did not report the ethnic/racial composition of the cohort, and it is possible that referral bias or other factors, which we were unable to detect on our review of the manuscript, contributed to this observation.…”

A population‐based epidemiological study of neuromyelitis optica spectrum disorder in Hungary

“…2,3 Previous epidemiological studies have suggested that NMOSD is less frequent in Caucasian populations compared to Asian, African and Latin American populations. [4][5][6][7][8] However, the number of large, population-based epidemiological studies is still scarce, and none is available from Eastern Europe.…”