To investigate whether polymorphic differences can be identified between Multiple Sclerosis patients developing elevated liver enzymes (defined as ALT, AST, GGT or bilirubinemia levels five above the upper normal limit on at least one) compared to those not developing elevated liver enzymes after exposure to fingolimod for multiple sclerosis.

PURPOSE: To investigate whether polymorphic differences can be identified between Multiple sclerosis (MS) patients treated by fingolimod who had liver enzymes elevation compared to those who do not.

OBJECTIVE: To determine whether elevated liver enzyme tests (ALT, AST, GGT or bilirubinemia above the upper limit of normal) in MS patients treated with fingolimod is associated with genetic polymorphisms.

METHOD OF RECRUITMENT:

Patients will be identified through a clinic database and chart reviews. A phone call will be made to determine interest. Upon a follow-up neurological consultation, consent into study will be sought.

PROCEDURES:

Blood samples will be collected for genetic analyses, fingolimod and fingolimod-phosphate quantification and a questionnaire will be administered

Inclusion Criteria:

• Adults (> 18 years)
• Have a definite Multiple Sclerosis with a relapsing-remitting course (McDonald criteria)
• Treated with fingolimod
• Have given consent and signed an informed consent form

Exclusion Criteria:

• an elevated liver test result on baseline before starting fingolimod treatment
• presence of a viral, hereditary or auto-immune liver pathology
• Time of fingolimod exposure lower than three months
• Woman currently pregnant or breastfeeding

Multiple sclerosis (MS) patients attending out-patient neurological consultations in Caen University Hospital, with a relapsing-remitting disease course, and prescribed fingolimod as a disease-modifying drug for MS.