The immune system protects the body against foreign substances such as bacteria and viruses, while not reacting to the cells of the body, recognizing the latter as belonging to the body. In the case of an autoimmune disease, tolerance mechanisms fail, and antibodies will attack the body's own cells: they are called autoantibodies, which will generate an autoimmune disease. The causes are not fully identified in the onset of this type of disease, but genetic and hormonal factors as well as the individual's environment (infection, toxicity of certain molecules ...) seem to play a role. Autoimmune diseases have an evolution that is unpredictable and cluttered with successive relapses, and they can affect a single organ, or affect the entire body. Because of their occurrence over shared mechanisms, it frequently happens that several autoimmune diseases erupt in the same individual.
The symptoms will differ depending on the disease and the affected organs. Among systemic autoimmune diseases, i.e. not affecting a body specifically, they include:
As for autoimmune diseases specifically affecting an organ, symptoms may include:
The diagnosis is made after a clinical examination of the patient, in order to highlight the symptoms and underline a pathology. Additional tests will be prescribed according to the suspected pathologies. The common thread is the ability to find, in a blood sample, specific autoantibodies, such as anti-thyroid peroxidase in thyroiditis, anti-acetylcholine receptors in myasthenia gravis, anti- insulin in diabetes, or non-specific autoantibodies that highlight the presence of an autoimmune disorder.
Treatment will also vary depending on the disease in question. In general, corticosteroids or immunosuppressive agents are used over long periods of time to reduce the non-specific antibodies. However, they must be accompanied by biological monitoring so as not to leave the body defenseless. In autoimmune organ-specific diseases, treatments tailored to the organ in question are possible, such as insulin for diabetes and thyroid hormones in thyroiditis.