INFLANET - A French Network for PET imaging of neuroinflammation in MS

Lab values

• all participants: - Any reasons, which does not allow to perform MRI, including claustrophobia, the implant of a pace-maker or the presence of an intra-ocular foreign body, (a contra-indication questionnaire will be filled in beforehand) - PET for clinical research already done within the last 12 months - Low Affinity Binding profile (analyse of TSPO polymorphism done at screening visit) - Pregnancy, breast-feeding, lack of efficient contraception for women of childbearing potential - Current symptoms of severe or uncontrolled renal, hepatic, hematological, gastrointestinal, pulmonary or cardiac disease, or any other chronic neurological diseases - Unwillingness to be informed in case of unexpected MRI abnormality (with a significant medical anomaly) - Patient under legal protection - Participation in another interventional study or being in the exclusion period at the end of a previous study RRMS patients: - hypersensitivity to gadoteric acid - meglumine or any drug containing gadolinium - Severe renal insufficiency (creatinine clearance < 60mL/min and GFR <30ml / min / 1.73m2).

• RRMS patients: - Age between 18 and 55 years old - RRMS according to the 2017 Mc Donald criteria - Last treatment with methylprednisolone should have been performed at least 1 month before PET examinations - No current disease modifying therapy or under platform therapy (dimethyl fumarate, teriflunomide, beta-interferons, glatiramer acetate)- Indication for a highly active disease modifying treatment: Natalizumab, anti CD20 antibody, Alemtuzumab, sphingosine-1 phosphate modulator, or cladribine. This will consist either as patients with an active form of relapsing MS or patients who have experienced two relapses during the previous year - Affiliation to a social security scheme or beneficiary of such a scheme (except “Aide Médicale d’Etat”) Healthy Volunteers: - Age between 18 and 55 years old - Without any evolutive pathology - Able to understand the study objectives and procedures - Affiliation to a social security scheme or beneficiary of such a scheme (except “Aide Médicale d’Etat”)