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.