2 DISEASES DISORDERS OF THE IMMUNE SYSTEM WARM UP Do you suffer from any form of allergy? If so, what causes the allergy? What are the symptoms? Types of immune system disorders When the immune system, which protects the body against infection and harmful invaders, does not work properly, it causes an . There are many different types of immune system disorders, including immunodeficiency diseases, autoimmune disorders and allergic disorders. immune system disorder Immunodeficiency disorders They cause a weakening of the immune system, allowing infections and other health problems to occur more easily. (also called primary immune disorders) are those you are born with. They are the result of genetic defects and most of them are inherited. (also called acquired immunodeficiency) occur when the immune system is compromised due to an environmental factor or by a disease (HIV/AIDS, chemotherapy, malnutrition). Primary immunodeficiencies Secondary immunodeficiencies (Acquired Immune Deficiency Syndrome) is a very serious disorder which may happen when the immune system has been severely damaged. It is caused by (Human Immunodeficiency Virus) which destroys T-cells until the immune system is unable to fight off even minor illnesses. The three stages of HIV infection are: (1) acute HIV infection, (2) chronic HIV infection and (3) AIDS. AIDS HIV Autoimmune diseases Sometimes the immune system’s recognition apparatus , and the body begins to . Such cells and autoantibodies contribute to many diseases which can affect almost any part of your body. For instance, T-cells that attack pancreas cells contribute to diabetes, while an autoantibody known as rheumatoid factor is common in people with rheumatoid arthritis. breaks down manufacture antibodies and T-cells directed against the body’s own cells and organs Allergic disorders Allergic disorders are caused by an which reacts to substances in the environment that are normally harmless. These substances are called . Some conditions caused by an overactive immune system are: asthma, allergic rhinitis, eczema – with symptoms such as , , red eyes, an rash, coughing, a runny nose, shortness of breath, or . Allergens may be dust, grass and tree pollen, food – particularly nuts, fruit, shellfish, eggs and cows’ milk – insect and medicines. 1 overactive immune system allergens 1 wheezing sneezing itchy swelling bites MORE The number of people with allergies is increasing every year. The reasons for this are not understood, but is probably the result of living in a cleaner, germ-free environment in much of the world, which reduces the number of germs our immune system has to deal with. 1 DO Substances that cause allergic reactions are called allergens. Do you know the most common ones? 1