BY: SAI MANOGNA (MSIWM014)
The body protects against disease and infection with a robust immune system. However, if the immune system malfunctions, the healthy cells, tissues, and organs are wrongly targeted, leads to autoimmune disease. They affect any part of the body, weaken the body’s function, and even make it life-threatening.
There are more than 80 autoimmune disorders. Some, such as multiple sclerosis, type 1 diabetes, lupus, and rheumatoid arthritis, are well known, while others are rare and hard to diagnose. Patients can suffer from rare autoimmune diseases years before they receive a proper diagnosis. There is no treatment for these diseases. To relieve symptoms, some need lifelong care.
Association of autoimmunity with a disease:
There is considerable diversity in the immune system, and since the repertoire of specificities expressed by the populations of B and T cells is produced randomly, it is bound to include those specific to self-components. Therefore, the body must develop mechanisms of self-tolerance to differentiate between determinants of self and non-self to prevent autoreactivity. However, there is a risk of a breakdown in the autoimmunity system. The processes of self-recognition are no exception, and a variety of illnesses have been reported.
Types Of Autoimmune diseases:
Autoimmune diseases are of two types;
- Organ-specific autoimmune diseases
- Non-organ specific autoimmune diseases
Organ-specific: It typically affects a single organ, and the autoimmune response inside that organ is directed against antigens.
E.g., Hashimoto’s thyroiditis,
Type I diabetes mellitus,
autoimmune pernicious anemia,
autoimmune Addison’s disease.
Non-organ specific: They affect several organs and are typically associated with responses widely spread across the body toward self-molecules.
Primary Sjogren’s syndrome.
Autoimmune diseases – Spectrum:
Hashimoto’s thyroiditis-associated antibodies and primary myxoedema interfere only with the thyroid, so the resulting lesion is highly localized. On the other hand, the serum of patients with diseases such as systemic lupus erythematosus ( SLE) responds to a few, if not all, of the body’s tissues. In SLE, the cell nucleus is directed against one of the dominant antibodies. These two diseases define the poles of the autoimmune spectrum. The thyroid, adrenals, stomach, and pancreas are the specific target organs in organ-specific diseases. Non-organ-specific diseases, including rheumatological disorders, usually affect the skin, kidneys, joints, and muscles.
1. Autoimmunity occurs due to the abundant development of autoantibodies and autoreactive T cells.
2. Hashimoto’s thyroiditis is one of the earliest cases in which the development of autoantibodies was associated with illness in a given organ.
3. Thyroiditis has been particularly well-studied among autoimmune diseases. It is a thyroid condition that is most common in women of middle age and sometimes contributes to goiter formation and hypothyroidism.
4. The gland is invaded by inflammatory lymphoid cells, often to an exceptional degree. 5. These are primarily mononuclear phagocytes, lymphocytes, and plasma cells, and it is normal to have secondary lymphoid follicles.
6. The gland also exhibits regenerating thyroid follicles in Hashimoto’s disease. However, this is not a thyroid function in the associated disorder, primary myxoedema, in which comparable immunological characteristics are seen and where the gland is almost destroyed and shrinks.
7. The serum of patients with Hashimoto’s disease naturally produces thyroglobulin antibodies.
8. These antibodies, when present in high titers, are demonstrable by agglutination and precipitin reactions.
9. There are also antibodies to the cytoplasmic or microsome antigen in most patients, which are also present on the follicular epithelial cells’ apical surface and are now considered to be thyroid peroxidase, the iodinating thyroglobulin enzyme.