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

Abstract

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 (Wingerchucks 1999 criteria): Cuba (24)/FWI (24), employing Lennon et aĺs 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.