Therapeutic efficacy of dimethyl fumarate in relapsing-remitting multiple sclerosis is linked with monocytic oxidative responses [Affymetrix]

Dimethyl fumarate (DMF) is a first-line-treatment for relapsing-remitting multiple sclerosis (RRMS). The redox master regulator Nrf2, essential in redox balance, is a target of DMF, but the precise therapeutic mechanisms remain elusive. Here we show impact of DMF on circulating monocytes and T cells in a prospective longitudinal RRMS patient cohort. DMF increased the level of oxidized isoprostanes in peripheral blood. Other observed changes, including methylome and transcriptome profiles, occur in monocytes prior to T cells. Importantly, monocyte counts and monocytic ROS increase following DMF and distinguish patients with beneficial treatment-response from non-responders. A single nucleotide polymorphism in the ROS-generating NOX3 gene is associated with beneficial DMF treatment-response and suggestively associated with increased ROS generation. Our data implicate monocyte-derived oxidative processes in autoimmune diseases and their treatment, and identify NOX3 genetic variant, monocyte counts and redox state as parameters potentially useful to inform clinical decisions on DMF therapy of RRMS. 14 multiple sclerosis patients at baseline or after 6 months after DMF treatment. Extracted Celltypes are CD4+ Tcells from the same patients.