Multiple sclerosis (MS) is an immune-mediated disease characterized by chronic inflammation, demyelination, gliosis, and neuronal loss within the central nervous system (CNS). The etiology of MS is multifactorial, involving genetic, immunological, and environmental components.
Key Aspects of MS Etiology:
1. Immune System Dysregulation: MS is primarily driven by aberrant immune responses, with T lymphocytes and B lymphocytes contributing to myelin and oligodendrocyte damage. The activation of autoreactive T cells by environmental triggers leads to CNS infiltration and subsequent inflammatory cascades.
2. Genetic Susceptibility: Genetic predisposition plays a crucial role in MS, with over 200 genetic loci identified that confer susceptibility. The HLA-DRB1*15:01 allele is one of the most significant genetic risk factors. Other genetic polymorphisms involved in immune regulation are also implicated.
3. Environmental Triggers: Environmental factors such as viral infections (e.g., Epstein-Barr virus), low vitamin D levels, smoking, and geographic location (higher latitude) have been associated with an increased risk of MS. These factors may interact with genetic susceptibility to trigger the autoimmune response.
4. Pathophysiological Mechanisms: The pathophysiology of MS involves both adaptive and innate immune mechanisms. Key processes include blood-brain barrier disruption, autoreactive lymphocyte activation, demyelination, and axonal damage. Chronic inflammation leads to neurodegeneration and clinical disability.
Verified by Dr. Petya Stefanova
