Prognostic factors associated with long-term disability and secondary progression in patients with Multiple Sclerosis

Abstract

Background: Predicting the long-term prognosis of patients with multiple sclerosis (MS) remains an uncertain and difficult task, with most data having been obtained exclusively from Caucasian cohorts.

Objective: To investigate clinical prognostic factors in a Brazilian mixed-race cohort.

Methods: Demographic, clinical and therapeutic factors were investigated in 303 patients with relapsing-remitting MS in relation to the following outcomes: time until reaching Expanded Disability Status Scale (EDSS) 3 and EDSS 6, and until secondary progression.

Results: Benign course was significantly more frequent among Caucasians when compared to Afrodescendants. Patients with a malignant course had more than one relapse in the first year of the disease and reached EDSS 3 faster if treatment was not started. In the multivariate analysis, the following factors were associated with a significantly shorter time until the established outcomes: male gender, being of African descent, non-recovery after the first relapse, two or more relapses during the first year, a short interval between initial relapses, initial polysymptomatic presentation of pyramidal and cerebellar dysfunction and no treatment prior to reaching EDSS 3.

Conclusions: Being of African descent was found to be an unfavorable factor for all outcomes, reinforcing the need to take ethnicity into consideration when defining treatment, particularly in mixed MS populations.

Keywords: African Ancestry; Disability; Multiple Sclerosis; Prognostic factors; Risk factors; Secondary progression.