Multiple Sclerosis - an autoimmune disease
Multiple sclerosis (MS) affects approximately 2.5 Million individuals worldwide and 10’000 in Switzerland. The first symptoms are normally recognized between an age of 20 to 40 years and more females than males (ratio 2-3 : 1) are affected. It is considered a prototypic T cell-mediated autoimmune disease at which the central nervous system (CNS) is attacked. As a result, MS causes a broad range of mostly slowly increasing deficits including impaired motor and sensory function, visual deficits, autonomic and neurocognitive dysfunctions. At first clinical observation, the disease is referred to as clinically isolated syndrome (CIS), which after a second event (another symptom than the first one) turns into relapsing-remitting MS (RRMS). The RRMS can turn after a period of time into a stage of steadily increasing neurological deficits, called then secondary progressive MS (SPMS) , and a small subgroup of patients (10%) shows chronic progression from the beginning (primary progressive MS, PPMS). During the past two decades, new therapy approaches have been approved. However still a lot of patients develop disabilities and are restricted in their work and private life.
The cause of MS involves a complex genetic trait with more than 100 quantitative trait loci, but also environmental factors e.g., Epstein Barr virus (EBV), smoking and low vitamin D3 levels. These conditions can lead to a dysfunctional immune regulation and an inflammatory process targets the myelin sheath of the CNS and the spinal cord and leads to their degradation. During the chronic progressive stage, adaptive immune processes (antigen-specific immunity) decline, and innate immune responses including chronic microglial activation become more and more prominent.
Due to the complexity of the causal factors, the disease is characterized by heterogeneity in the main pathogenetic mechanisms and thus the symptoms and their characteristics are highly diverse from patient to patient.