inclusion criteria: (1) diagnosis of multiple sclerosis (ms) according to 2017 mcdonald criteria. (2) age \>=18 years. (3) treatment with teriflunomide for at least 6 months/or 4 to 18 months after the last course treatment with alemtuzumab/or untreated. (4) signed written informed consent.

inclusion criteria: (1) diagnosis of multiple sclerosis (ms) according to 2017 mcdonald criteria. (2) age \>=18 years. (3) treatment with teriflunomide for at least 6 months/or 4 to 18 months after the last course treatment with alemtuzumab/or untreated. (4) signed written informed consent.

inclusion criteria: (1) diagnosis of multiple sclerosis (ms) according to 2017 mcdonald criteria. (2) age >=18 years. (3) treatment with teriflunomide for at least 6 months/or 4 to 18 months after the last course treatment with alemtuzumab/or untreated. (4) signed written informed consent.

inclusion criteria: (1) diagnosis of multiple sclerosis (ms) according to 2017 mcdonald criteria. (2) age >=18 years. (3) treatment with teriflunomide for at least 6 months/or 4 to 18 months after the last course treatment with alemtuzumab/or untreated. (4) signed written informed consent.