The immune system is the most complex body system. The immune system is spread throughout the entire body. It is composed of several levels and numerous cell types and molecules that work together to provide immune responses. The immune system and its associated responses have many functions, but the most important one is to protect the body from foreign substances. The word ‘immunity’ means ‘exemption’ which refers to a body that is free from disease (Craft, Gordon, & Tiziani, 2014).
For a foreign substance such as a microorganism to enter the body it must pass through highly effective physical barriers, such as the skin, and chemical barriers, such as enzymes in the gastric fluid that minimise the spread and impact of these agents. These first-line barriers are supplemented by inflammation that limits damage and initiates repair (Craft et al., 2014).
What is an autoimmune disease?
When the body senses foreign invaders, it responds with its defence mechanism targeting the foreign invaders. In normal circumstances, the immune system can distinguish the difference between foreign cells and its own cells. In an autoimmune disease, the immune system mistakes part of the body such as the joints or skin as foreign invaders. Therefore it releases the defence mechanism to attack the joints or skin. Some autoimmune diseases target only one organ. A common known autoimmune disorder is Type 1 diabetes. It only damages the pancreas. Others can affect the whole body such as lupus.
Why does the immune system attack the body?
Genetic predisposition, environmental factors (including infections), and gut dysbiosis play major roles in the development of autoimmune diseases. Autoimmunity develops over time and can be detected in the peripheral blood in the form of circulating autoantibodies. Symptoms of autoimmune disorders are including fatigue, low-grade fever, muscle and joint aches, and malaise. Sufferers of immune disorder seek out for help when their disease process has become symptomatic, clouding the understanding of the early events leading to disease. In general, clinicians familiar with triggers for autoimmunity can use the right combination of laboratory analyses to explain the type and stage of the patient’s autoimmune reaction. With the proper information, it may help the clinician to initiate a preventative treatment aimed to reverse the progression of the autoimmune disorder and better chances to a possible elimination of the autoimmune disease (Campbell, 2014).
There is evidence of a steady rise in autoimmune disease throughout Westernized societies over the last decades. Rheumatic, endocrinological, gastrointestinal and neurological autoimmune diseases are growing at an annual rate 7.1%, 6.3%, 6.2%, and 3.7% respectively. Multiple sclerosis (MS), type 1 diabetes (IDDM), inflammatory bowel diseases (mainly Crohn’s disease) (IBD), systemic lupus erythematosus (SLE), primary biliary cirrhosis, myasthenia gravis (MS), autoimmune thyroiditis (AT), hepatitis and rheumatic diseases (RA), bullous pemphigoid, and celiac disease (CD) are several examples. The three major environmental factors, strongly related to socio-economic status are suspected to drive these phenomena: infections, ecology and nutrition (Lerner, Jeremias, & Matthias, 2015).
The overall estimated prevalence is 4.5%, with 2.7% for males and 6.4% for females (Hayter & Cook, 2012).
There’s suggestion that the Western diet, including high-fat and cholesterol, high-protein, high-sugar, and excess salt intake, as well as frequent consumption of processed and ‘fast foods’, promote obesity, metabolic syndrome, and cardiovascular disease are possible promoters of autoimmune diseases (Manzel et al., 2014).
Some of the most common autoimmune diseases
It is known the existence of more than 80 autoimmune disorders (Campbell, 2014). The following are some of the most common known autoimmune diseases.
Type 1 diabetes
The pancreas produces the hormone insulin, which helps regulate blood sugar levels. In type 1 diabetes, the immune system attacks and destroys insulin-producing cells in the pancreas. High blood sugar can damage blood vessels, as well as organs like the heart, kidneys, eyes, and nerves.
Type 1 diabetes affects 35,500 people over the age of 25 in Australia (Craft et al., 2014, p. 256)
Rheumatoid arthritis (RA)
In rheumatoid arthritis (RA), the immune system attacks the joints. This attack causes redness, warmth, soreness, and stiffness in the joints. Besides inflammation of the joints, rheumatoid arthritis can cause fever, malaise, rash, lymph node or spleen enlargement and Raynaud’s phenomenon (Craft et al., 2014, p. 553).
Psoriasis is a chronic immune-mediated inflammatory disorder of the skin. It causes skin cells to multiply and build up faster. The extra cells build up to form red, scaly patches called scales or plaques on the skin. About 30 percent of people with psoriasis also develop swelling, stiffness, and pain in their joints known as psoriatic arthritis (Ritchlin, Colbert, & Gladman, 2017).
Multiple sclerosis (MS) is a chronic autoimmune, inflammatory neurological disease of the central nervous system. In MS, the myelin sheath which is a protective coating that surrounds nerve cells gets damaged. This damage affects the transmission of messages between the brain and the body. Most common symptoms are numbness, weakness, balance issues and trouble walking. The disease progresses at different rates. About 50 percent of people with MS need help walking within 15 years after getting the disease (Goldenberg, 2012).
Systemic lupus erythematosus (lupus)
Systemic lupus erythematosus (SLE) is a complex and serious autoimmune disorder that affects more than 17,000 individuals in Australia. It affects many organs, including the joints, kidneys, brain, and heart. Joint pain, fatigue, and rashes are among the most common symptoms (Craft et al., 2014, p. 345).
Inflammatory bowel disease
Inflammatory bowel disease (IBD) is a term used to describe conditions that cause inflammation in the lining of the intestines. Each type of IBD affects a different part of the GI tract.
Crohn’s disease can inflame any part of the GI tract, from the mouth to the anus. Ulcerative colitis affects only the lining of the large intestine (colon) and rectum (Craft et al., 2014, p. 814).
Addison’s disease affects the adrenal glands. The adrenal glands are small hormone-secreting organs located on top of each kidney. They produce three types of hormones: glucocorticoid hormones, mineralocorticoid hormones and sex hormones:
- The glucocorticoid hormones (such as cortisol) maintain glucose control, suppress immune response and help the body respond to stress
- The mineralocorticoid hormones (such as aldosterone) regulate sodium and potassium balance
- The sex hormones, androgens and oestrogens, affect sexual development and reproduction
Common symptoms can be a weakness, fatigue, weight loss, and low blood sugar (Hechtman, 2012, p. 1124).
Graves’ disease is an autoimmune disease characterised by hyperthyroidism. The excess thyroid hormones affect the body’s energy usage or metabolism. Too much of thyroid hormones increase your body’s activities, causing symptoms like nervousness, a fast heartbeat, heat intolerance, and weight loss (Hechtman, 2012, p. 1069).
Hashimoto’s disease is an autoimmune disorder. The condition creates antibodies that attack the cells of the thyroid causing inflammation and, in most cases, eventual destruction of the gland. In Hashimoto’s thyroiditis, thyroid hormone production slows. Symptoms include weight gain, sensitivity to cold, fatigue, hair loss, and swelling of the thyroid (Department of Health & Human Services, n.d.).
This condition affects a protein called intrinsic factor that helps the intestines absorb vitamin B-12 from food. Without this vitamin, the body can’t make enough red blood cells. Pernicious anaemia is more common in older adults. It affects 0.1 percent of people in general, but nearly 2 percent of people over age 60 (Andres & Serraj, 2012).
Celiac disease is a multisystem immune-based disorder that is triggered by the ingestion of gluten. Gluten is a protein found in wheat, rye, and other grain products. When gluten is in the intestine, the immune system attacks it and causes inflammation (Lebwohl, Ludvigsson, & Green, 2015).
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Craft, J., Gordon, C., & Tiziani, A. (2014). Understanding pathophysiology – ANZ adaptation. Mosby Australia.
Department of Health & Human Services. (n.d.). Thyroid – Hashimoto’s disease. Retrieved March 1, 2018, from https://www.betterhealth.vic.gov.au:443/health/conditionsandtreatments/thyroid-hashimotos-disease
Goldenberg, M. M. (2012). Multiple Sclerosis Review. Pharmacy and Therapeutics, 37(3), 175–184. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3351877/
Hayter, S. M., & Cook, M. C. (2012). Updated assessment of the prevalence, spectrum and case definition of autoimmune disease. Autoimmunity Reviews, 11(10), 754–765. https://doi.org/10.1016/j.autrev.2012.02.001
Hechtman, L. (2012). Clinical Naturopathic Medicine. Sydney, Australia: Churchill Livingstone/Elsevier Australia.
Lebwohl, B., Ludvigsson, J. F., & Green, P. H. R. (2015). Celiac disease and non-celiac gluten sensitivity. The BMJ, 351. https://doi.org/10.1136/bmj.h4347
Lerner, A., Jeremias, P., & Matthias, T. (2015). The World Incidence and Prevalence of Autoimmune Diseases is Increasing. International Journal of Celiac Disease, International Journal of Celiac Disease, 3(4), 151–155. https://doi.org/10.12691/ijcd-3-4-8
Manzel, A., Muller, D. N., Hafler, D. A., Erdman, S. E., Linker, R. A., & Kleinewietfeld, M. (2014). Role of “Western Diet” in Inflammatory Autoimmune Diseases. Current Allergy and Asthma Reports, 14(1), 404. https://doi.org/10.1007/s11882-013-0404-6
Ritchlin, C. T., Colbert, R. A., & Gladman, D. D. (2017). Psoriatic Arthritis. New England Journal of Medicine, 376(10), 957–970. https://doi.org/10.1056/NEJMra1505557