The transcript mentions that in people with multiple sclerosis, T helper cells (Th cells) are more likely to have a Th1 phenotype compared to a Th2 phenotype. This Th1 phenotype is associated with inflammation in the disease.
This video discusses Dr. Pete DeGruijl's theory on the cause of autoimmune diseases. Dr. Beaber recounts a conversation with Dr. DeGruijl, a gastroenterologist, at a neurology conference, where DeGruijl presented his theory, which suggests that somatic mutations in lymphocytes, rather than solely inherited genetic factors, play a significant role in the development of autoimmune diseases. The video explores this theory using examples like type 1 diabetes and multiple sclerosis, examining supporting and contradicting evidence.
Somatic Mutation Theory: Dr. DeGruijl's theory posits that somatic mutations in lymphocytes (B and T cells) are a primary cause of autoimmune diseases. These mutations, acquired during life, alter the lymphocytes' characteristics, leading them to attack self-antigens.
Epidemiological Correlation: The prevalence of multiple autoimmune diseases in individuals is highly correlated, suggesting a common underlying factor, supporting DeGruijl's theory.
Genetic Predisposition: While genes, particularly HLA genes, significantly influence the risk of autoimmune diseases, they don't fully explain their development. Specific HLA gene variants are associated with increased risk for certain diseases, but the vast majority of people with these variants don't develop the disease.
Environmental Factors: Environmental factors like radiation, smoking, diet, and exposure to toxins might contribute to somatic mutations in lymphocytes and increase autoimmune disease risk. A healthier lifestyle might reduce this risk.
Limited Evidence: The somatic mutation theory is preliminary; while some evidence supports it (e.g., studies showing mutations in T lymphocytes of individuals with type 1 diabetes), more research is needed to validate it fully. Challenges include the rarity of autoreactive lymphocytes and the complexity of autoimmune diseases (polyantigenic).
The transcript states that some somatic mutations occur spontaneously due to imperfections in DNA replication. Others may be caused by environmental factors such as radiation (including radiation from space), smoking, diet, ultraviolet radiation, and toxic chemicals. The transcript does not offer a comprehensive definition of somatic mutations beyond their role in the context of Dr. DeGruijl's theory of autoimmune disease.
