Response to interferon-Beta treatment in afro-caribbeans with multiple sclerosis

Background. Multiple sclerosis (MS) patients of African ancestry have a more aggressive disease course than white patients and could be resistant to interferon-beta (INFB). Methods. We studied the impact of INFB in treatment-naive Afro-Caribbean (AC) with clinically definite MS using our European Database for Multiple Sclerosis (EDMUS) (2003-2010). Main outcome measures were annual relapse rate after 2 years of treatment, proportion of exacerbation-free subjects 48 weeks after initiating INFB, and time to first relapse. Results. 76 AC-MS (59F/17M) were identified. Annual relapse rate of 1.29 decreased to 0.83 (-35.6%) after 2 years of treatment. The proportion of relapse-free patients at 48 weeks was 46.2%. Median time to first relapse was 52 weeks. Conclusion. INFB is not strong enough to control AC-MS patients in many cases which is problematic in a population of worse MS prognosis.