BackgroundGender appears to play a role in incidence and disease course of multiple sclerosis (MS). ObjectiveThe objective was to determine whether male and female patients with MS respond differently to interferon-beta treatment in terms of reduction in relapse rates. MethodsWe included all 2033 patients with relapsing-remitting MS who started treatment with interferon-beta from 1996 to 2003, identified from the Danish Multiple Sclerosis Treatment Register. We defined neutralizing antibody (NAb)-positive and NAb-negative periods in the single patient by the results of the NAb tests. Patients served as their own controls, and relapse rates were compared between NAb-negative and NAb-positive periods. ResultsNAbs significantly abrogated the interferon-beta treatment efficacy in both genders. The all-over women:men relapse rate ratio irrespective of NAb status was 1.47 (95%CI; 1.28-1.68). In a generalized linear Poisson models analysis with relapse counts as response variable, the main effects NAbs, sex, age at treatment start and number of relapses in 2years before treatment start were strongly significant, but the effect of NAbs on relapse rates did not differ significantly between men and women. ConclusionAs NAbs influenced the on-treatment relapse rates strongly in both sexes but without statistical significant difference, there is no indication of different effects of interferon-beta in men or women.
Acta Neurologica Scandinavica, 2014, Vol 130, Issue 6, p. 374-379