Immunology & Immunological disorder
The immune system protects us from infection with layered defenses of increasing specificity.
Disorders of the immune system can result in autoimmune diseases, inflammatory diseases and cancer. Immunodeficiency occurs when the immune system is less active than normal, resulting in recurring and life-threatening infections. In humans, immunodeficiency can either be the result of a genetic disease such as severe combined immunodeficiency, acquired conditions such as HIV/AIDS, or the use of immunosuppressive medication. In contrast, autoimmunity results from a hyperactive immune system attacking normal tissues as if they were foreign organisms. Common autoimmune diseases include Hashimoto’s thyroiditis, rheumatoid arthritis, diabetes mellitus type 1, and systemic lupus erythematosus.
Another important role of the immune system is to identify and eliminate tumors. The main response of the immune system to tumors is to destroy the abnormal cells using killer T cells, sometimes with the assistance of helper T cells. Cancer immunotherapy covers the medical ways to stimulate the immune system to attack cancer tumours.