Neuromyelitis optica positive antibodies confer a worse course in relapsing-neuromyelitis optica in Cuba and French West Indies

Background In Caucasian populations Neuromyelitis Optica (NMO-IgG) antibody has been detected in 27.1%/78.2% of patients with relapsing-NMO (R-NMO). The prevalence reported for the disease in the Caribbean is 3.1/100,000 in the French West Indies (FWI) and 0.52/100,000 in Cuba, but the NMO antibody status is unknown. Objective To assess the NMO-IgG antibody status of Cuban/FWI RNMO patients, comparing with European cases tested at the same laboratories. Methods Serum NMO-IgG antibodies were assayed in 48 R-NMO patients (Wingerchuck's 1999 criteria): Cuba (24)/FWI (24), employing Lennon et al's method. We compared the demographic, clinical, disability and laboratory data between NMO-IgG +/- patients. All the data were reviewed and collected blinded to the NMO-IgG status. Results Seropositivity of the NMO-IgG antibody demonstrated a lower rate in the Caribbean (33.3%), as compared with Caucasian patients from Spain/Italy (62.5%) and France (53.8%). Caribbean patients with NMO-IgG (+) displayed more attacks, more spinal attacks and a higher EDSS than NMO-IgG (-) cases, while brain and spinal cord MRI lesions were more frequent during remission, with more vertebral segments, more gray, white matter and holocord involvement. Conclusions NMO IgG positive antibodies in NMO patients had a lower rate in the Caribbean area where the population has a predominant African ancestry - than in Caucasian Europeans, suggesting the influence of a possible ethnic factor in the pathogenesis of the disease, but they confer a worse course with more attacks, more disability and MRI lesions. Multiple Sclerosis 2009; 15: 828-833. http://msj.sagepub.com