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

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.