Autoimmune diseases are defined as “frequent pathologies which probably affect 5% to 10% of the population, reaching any organ of the body and sometimes several organs, presenting a wide spectrum of severity, and are due to a malfunction of the immune system which begins by attacking the body itself”, explains the Nucleus for the Study of Autoimmune Diseases of the Portuguese Society of Internal Medicine (NEDAI).
Although autoimmune diseases are not genetic diseases, a genetic predisposition is essential for their development. This means that certain gene combinations might lead to a higher risk of developing an autoimmune disease than others. In addition to a genetic predisposition, environmental factors also play a role. These are the stimuli which serve as a “connecting factor” to the immune system. Infections, vaccines, hormonal changes, smoke or nutritional deficiencies, among others, are considered environmental factors that may cause an autoimmune reaction.
The function of our immune system is to protect our body from diseases. The immune system of a healthy person immediately recognises the difference between “good” and “bad” organisms that constantly invade the human body. In people with an autoimmune disease, the immune system cannot make the distinction between “good” and “bad” organisms and will start attacking the “good” cells – that is attacking its own body.
There are over 80 autoimmune diseases:
▪ Systemic diseases such as rheumatoid arthritis, systemic lupus erythematosus, spondylitis, Sjogren’s syndrome, polymyositis, rheumatic polymyalgia, Goodpasture syndrome, among others.
▪ Specific-organ autoimmune diseases, such as Type 1 diabetes (pancreas), Graves’ disease (thyroid), Hashimoto’s thyroiditis (thyroid), multiple sclerosis (nervous system), myasthenia gravis (nervous system), Addison’s disease (adrenal glands), among others.
Some confusion may exist between symptoms caused by allergies and symptoms of an autoimmune disease. Although there are studies that reveal a link between allergies and the development of autoimmune diseases, the two diseases are quite different. People who suffer from allergies do not have an autoimmune system that attacks itself.
Autoimmune diseases are not contagious. They are chronic diseases that are often difficult to recognise and diagnose which may cause serious injury to various organs and can, in individual cases, endanger human life.
The symptoms are varied, not only in relation to each other, but also in comparison to the same disease. Due to the fact that these diseases affect various organs of the human body, their symptoms can be misleading, hindering the correct diagnosis. An accurate and complete medical history is therefore imperative.
The assistance of various complementary diagnostic examinations is needed, including the use of self-antibodies which can serve as markers for different diseases. The quality of these markers depends on their specificity and sensitivity.
The treatment of an autoimmune disease consists of the administration of anti-inflammatory drugs, corticosteroids, immunosuppressors and biological therapy. Biological therapies are based on the recent biotechnology, which help to identify a specific target responsible for the activity of the disease.
From a pharmacological point of view, there has been a fundamental and important evolution in the treatment of these diseases which can now benefit from highly specific and effective drugs that serve as blockers and target specific organs, subsequently treating structural damage caused by the disease. These drugs have revolutionised the treatment of certain autoimmune diseases, altering the natural history of the disease and therefore having a tremendous impact on the quality of life of the patient.
The multisystemic character of these pathologies, together with their variety, associated to the potential severity of these diseases, are constant challenges to the doctor who is treating a patient with an autoimmune disease, requiring constant and frequent updates. Early referral of these patients to a specialist in autoimmune diseases is the first step for an accurate diagnosis and treatment.
By Dr. Carlos Carneiro