Multiple sclerosis (MS) typically afflict young people in their twenties, when they start a career and establish a family. The disease thus imposes a severe impact on quality of life and heavy economic burdens on society. Critical barriers to progress in the field are the lack of knowledge of relevant immune cell subsets driving the pathology and the targets of the immune response within the central nervous system. In this project, we will test the hypothesis that a subgroup of MS patients is defined by a genetically determined B cell response against specific antigenic epitopes. The hypothesis is based on our recent, pioneering results showing that approximately half of MS patients have a restricted population of B cells in the cerebrospinal fluid defined by polymorphisms in the constant heavy-chain of the immunoglobulin B cell receptor, the G1m1 allotype. Here, we aim to characterize the G1m1 B cells, to disentangle the genetic basis of the B cell response, and to identify the molecular targets.

Inclusion Criteria:

• Symptoms and brain MRI scans strongly suggestive of multiple sclerosis according to the 2017 McDonald revisions
• Intrathecal immunoglobulin G synthesis
• Age > 18 years

Exclusion Criteria:

• Treatment with immunomodulatory drugs

Patients under diagnostic work-up for multiple sclerosis.