This study investigates whether there is a link between disease activity/progression in patients receiving Gilenya and expression of a putative biomarker signature in patients with multiple sclerosis.

Gilenya modulates expression of the sphingosine-1-phosphate receptor and inhibits egress of several lymphocyte subsets from lymph nodes. This results in immunosuppression that has a beneficial effect in patients with multiple sclerosis.

Our laboratory reported that increased expression of a possible biomarker signature, consisting of TLR2, TLR4 and CCR1, in a T-subset is associated with rapid MS progression. The investigators will test whether a significant proportion of patients at baseline upregulate this biomarker signature in one or more T-subsets, whether expression of this biomarker signature changes with treatment with Gilenya and whether expression levels of this signature predict disease activity or progression over a 12 month followup period. The investigators will study patients who are already being treated with Gilenya by their neurologists or who are already being treated with Gilenya as part of a clinical trial sponsored by Novartis Pharmaceuticals Canada. Patients will not be treated with Gilenya for the purposes of our study.

Inclusion Criteria:

• Treatment with Gilenya

Exclusion Criteria:

• Subject is under 18 or over 65.
• Subject has less than 4 weeks of discontinuation with steroid treatment for a relapse.
• Subject cannot communicate reliably with investigator.
• Vulnerable subjects exclude, namely patients defined as those without freedom by the law (e.g. prisoners or by administrative decision) or people hospitalized without their consent.

Patients treated with Gilenya compared with age-matched healthy controls