Autoimmune Diseases

• Context (IE): A recent study delves into the connection between autoimmune diseases and X-chromosomes, offering insight into why women are more susceptible to such disorders.

Linkage between X Chromosome and Autoimmune Diseases

• Females have two X chromosomes, while males have one X and one Y.
• The second X chromosome in females contains both active and inactive genes.
• The molecular coating of the X chromosome is a combination of RNA and proteins.
• It is crucial to a process called X chromosome inactivation, which ensures that one set of X chromosomes in females remains active and functional while the other is muffled.
• The chromosome is wrapped in long strands of RNA called XIST that attract proteins and tamp down the expression of the gene inside.
• The ones that escape the X inactivation process are thought to be the cause of autoimmune diseases.
• The XIST molecule, too, has been known to elicit inflammatory immune responses.

Autoimmune Diseases (AD)

• It occurs when the immune system mistakenly targets healthy cells and tissues in the body.
• Examples of AD: Rheumatoid Arthritis, Systemic Lupus Erythematosus, Type 1 Diabetes, Multiple Sclerosis, Celiac Disease, Hashimoto’s Thyroiditis, Psoriasis, and Inflammatory Bowel Disease.
• AD is more common in females, with a female-to-male ratio ranging from 10:1 to 1:1.
• They can occur at any age but are more common during the reproductive years.
• The presence of one AD in an individual increases the risk of developing another AD by 30-40%.
• Symptoms: Fever, malaise, fatigue, arthralgia, deformity, disability, increased risk of comorbidities like cancer, stroke, mental illnesses, infections and risk of early mortality.

Types of Autoimmune Diseases

• Organ-specific disease (involving only one organ) in which the immune response is directed toward antigens present in a single organ.
  • E.g. Autoimmune thyroiditis, multiple sclerosis, Diabetes Mellitus Type I, etc.
• Systemic disease in which the immune system attacks self-antigens in several organs.
  • E.g. Systemic lupus erythematosus is characterised by inflammation of the skin, mucus membranes, joints, kidneys, brain, intestines, etc.

What causes Autoimmune Diseases?

• Genetics: A family history of autoimmune diseases suggests a genetic predisposition, with specific genes increasing susceptibility to such disorders.
• Environmental Factors:
  • Microorganisms (bacteria or viruses) may trigger changes that confuse the immune system.
  • Epigenetic factors, which interact with genes, can also play a role.
• Hormonal Influence: Estrogen, a female sex hormone, has an impact on the immune system, and imbalances or inflammation in estrogen levels can heighten the risk of AD in women.
• Medications: Some medications can induce changes in the body that confuse the immune system; for instance, side effects of statins, antibiotics, and blood pressure medications may play a role.