The switch between relapse and remission in multiple sclerosis: continuous inflammatory response balanced by Th1 suppression and neurotrophic factors.

Multiple sclerosis (MS) is characterized in most patients by a relapsing-remitting disease course. However, the trigger of relapse and the transformation that switches relapse into remission are not clearly understood. To evaluate the key molecular pathways operating in MS relapse and remission we performed peripheral blood gene-expression profiling in 123 MS patients either in relapse (n=34) or remission (n=89) and in comparison with 41 matched healthy subjects using Affymetrix microarray technology. Our findings suggest that the relapsing-remitting pattern of MS is an ongoing process where inflammation is persistently active in the background of a changing magnitude of processes associated with TBX21-mediated immune suppression and activation of BDNF-related neuroprotection.