A tolerogenic composition for use in a method of treatment for multiple sclerosis (MS) in a MS patient exhibiting T-cell autoreactivity against an endogenous epitope corresponding to a T-cell epitope comprised in the amino-acid sequence of SEQ ID NO: 5, the composition comprising a therapeutic T-cell epitope comprising a sequence of 8 consecutive amino acid residues differing from a sub-sequence of SEQ ID NO: 5by 0-2residue substitutions, deletions and/or insertions, or the composition comprising a nucleic acid encoding said therapeutic T-cell epitope. A method for determining the degree of multiple sclerosis (MS) related autoimmunity in a test subject, comprising providing a test sample derived from the test subject comprising viable T-cells；quantitating antigen-specific activation of the T-cells of the test sample in vitro in response to a test antigen comprising a T-cell epitope, wherein said T-cell epitope is as the above therapeutic T-cell epitope above； and comparing the quantitated antigen-specific activation to a relevant reference to determine the degree of MS-related autoimmunity in the test subject.
