The immune system of the body protects it from diseases by fighting against various microorganisms including bacteria, fungus or virus that try to enter the body. However, sometimes due to a complex interaction between some genes and environmental factors, the immune system turns against our own body. Autoimmune diseases occur when the immune system mistakes its cells for foreign microorganisms and starts attacking them. There are around 100 autoimmune diseases, many of which are more prevalent in women. Let us understand the reason behind this disproportionate burden of autoimmune diseases in women.
Why women are at higher risk
Women have a higher incidence and prevalence of autoimmune diseases than men, and 85% or more patients of multiple autoimmune diseases are female. Some studies which provide an explanation for this include:
- A study published in the journal Frontiers in Endocrinology in 2019 stated that women are prone to autoimmune diseases as they undergo extensive endocrinological changes during puberty and pregnancy followed by breastfeeding and menopause. During these changes, the hormonal system interacts with the innate and acquired immune system of the body. The study concluded that these interactions can increase the susceptibility of women to develop autoimmune diseases.
- A study published in the journal Nature Communications found that the male sex hormone testosterone protects men against autoimmune diseases. The study found that testosterone suppresses the activity of BAFF. BAFF is a protein that activates the B cells that release inflammatory cells such as monocytes and macrophages. These inflammatory cells can trigger autoimmune diseases. Scientists concluded that since women do not have enough testosterone in their body, they do not have such protection. Furthermore, due to high levels of BAFF, women are more likely to suffer from systemic lupus erythematosus (SLE).
- Researchers from the University of Michigan discovered that women have more VGLL3 molecules in their skin than men, which increases their risk for autoimmune diseases. The research published in the journal JCI Insight found that VGLL3 promotes hyperactivity of the immune system and makes the immune cells self-attack the cells of the skin. The attack may extend from the skin to other internal organs. More VGLL3 in the skin cells has also been associated with the development of lupus.
- A study published in the journal Trends in Genetics found that the immune system of women hyperactivates during pregnancy to protect them and the foetus from possible pathogens and infections. However, this exacerbated immune response increases their risk of developing an autoimmune disease.
Autoimmune diseases in women
Some of the autoimmune diseases that are more prevalent in women include:
- Rheumatoid arthritis: In this condition, the immune cells attack the bone tissues resulting in inflammation, stiffness and pain in the multiple joints. This inflammation could also be seen in the lungs and eyes.
- Systemic Lupus Erythematosus (SLE): Also known as lupus, SLE results in inflammation in multiple parts of the body including the joints, skin, kidney, brain, lungs, and heart.
- Sjögren's syndrome: This condition results in a triad of symptoms, which include drying of eyes (keratoconjunctivitis), dry mouth (xerostomia) and rheumatoid arthritis. It can cause inflammation in the lungs and other vital organs.
- Multiple sclerosis: In this condition, the immune cells damage the myelin sheath, which is the lining of the nerve cells. Multiple sclerosis results in impairment of movement, balance, vision and other issues associated with the brain and the spinal cord.
- Thyroid disorders: Hypothyroidism, marked with a lack of enough thyroid hormone in the blood, is mostly seen in women. It is characterised by sudden weight gain, fatigue, cold intolerance, dry skin and muscular cramps.
- Type 1 diabetes: Type 1 diabetes is an autoimmune disorder where the immune system destroys the beta cells of the pancreas completely. Therefore, there is a lack of insulin in the blood, resulting in high blood sugar levels. Studies have shown that women are more prone to develop type 1 diabetes than men.
- Psoriasis: It is an autoimmune disorder where the skin cells multiply quickly, resulting in the shedding of the skin every 3 to 4 days. The affected person may develop inflammation, redness, and scaly skin on the scalp, elbows, palms of the hands, knees and lower back.
Early signs of autoimmune diseases
Though there are different types of autoimmune diseases, most of them have some common symptoms. Some of these common symptoms include:
- Skin issues like rashes, itching and flaking
- Recurring fever
- Unexplained weight gain or loss
- Pain in the abdomen
- Problems in the digestion
- Joint pain and swelling
- Persistent bloating or swelling
- Swollen glands
- Difficulty concentrating
The presence of any of these symptoms does not confirm an autoimmune disease as the doctors would require a series of tests to confirm the diagnosis. However, a person experiencing these symptoms must consult their doctor.
Risk factors for autoimmune diseases
The exact cause of autoimmune diseases is still unknown. However, several studies have indicated that hyperactivity of the immune system after an injury or a disease could be the reason for most autoimmune diseases. Some of the risk factors that may increase the risk of developing autoimmune disorders include:
- Family history: People with a family history of lupus or multiple sclerosis are at increased risk of developing the same as it may be transferred through the genes.
- Smoking: Several studies have shown that smokers are at a higher risk of developing autoimmune diseases such as lupus, hyperthyroidism, rheumatoid arthritis and multiple sclerosis.
- Weight issues: Since obese and overweight people have elevated stress on their joints, they are at increased risk of developing rheumatoid arthritis or psoriatic arthritis. Excessive fat tissue also promotes inflammation in the body, which can trigger an autoimmune disease.
- Medications: Some medications such as anti-hypertensives (blood pressure medications) and antibiotics can trigger medicine-induced lupus. Similarly, studies have shown that the use of statins (to reduce cholesterol) can trigger statin-induced myopathy, which is a rare autoimmune disease characterized by muscle weakness.
Studies reveal women are eight times more prone to developing autoimmune diseases, such as multiple sclerosis, lupus, and rheumatoid arthritis than men. The severity of autoimmune diseases can vary from mild manifestations to life-threatening ailments. Continuous research is being done to find out the reason for the hyperactivity of the immune system. Till now, there is no known prevention or cure for most autoimmune diseases. However, with the help of several therapies, most conditions can be managed effectively.