Information for Patients
Immune System and Disorders
Your immune system is a complex network of cells, tissues, and organs that work together to defend against germs. It helps your body to recognize these "foreign" invaders. Then its job is to keep them out, or if it can't, to find and destroy them.
If your immune system cannot do its job, the results can be serious. Disorders of the immune system include
- Allergy and asthma - immune responses to substances that are usually not harmful
- Immune deficiency diseases - disorders in which the immune system is missing one or more of its parts
- Autoimmune diseases - diseases causing your immune system to attack your own body's cells and tissues by mistake
Autosomal dominant hyper-IgE syndrome Autosomal dominant hyper-IgE syndrome (AD-HIES), formerly known as Job syndrome, is a condition that affects several body systems, particularly the immune system. Recurrent infections are common in people with this condition. Affected individuals tend to have frequent bouts of pneumonia, which are caused by certain kinds of bacteria that infect the lungs and cause inflammation. Inflammation is a normal immune system response to injury and foreign invaders (such as bacteria). However, excessive inflammation can damage body tissues. Recurring pneumonia often results in the formation of air-filled cysts (pneumatoceles) in the lungs. Frequent skin infections and an inflammatory skin disorder called eczema are also very common in AD-HIES. These skin problems cause rashes, blisters, accumulations of pus (abscesses), open sores, and scaling.For unknown reasons, people with AD-HIES have abnormally high levels of an immune system protein called immunoglobulin E (IgE) in the blood. IgE normally triggers an immune response against foreign invaders in the body, particularly parasitic worms, and is involved in allergies. However, IgE is not needed for these roles in people with AD-HIES, and it is unclear why affected individuals have such high levels of the protein without having allergies.AD-HIES also affects other parts of the body, including the bones and teeth. Many people with AD-HIES have skeletal abnormalities such as an unusually large range of joint movement (hyperextensibility), an abnormal curvature of the spine (scoliosis), reduced bone density (osteopenia), and a tendency for bones to fracture easily. A common dental abnormality in this condition is that the primary (baby) teeth do not fall out at the usual time during childhood but are retained as the adult teeth grow in. Other signs and symptoms of AD-HIES can include abnormalities of the arteries that supply blood to the heart muscle (coronary arteries), distinctive facial features, and structural abnormalities of the brain, which do not affect a person's intelligence.
DOCK8 immunodeficiency syndrome DOCK8 immunodeficiency syndrome is a disorder of the immune system. The condition is characterized by recurrent infections that are severe and can be life-threatening. The infections can be caused by bacteria, viruses, or fungi. Skin infections cause rashes, blisters, accumulations of pus (abscesses), open sores, and scaling. People with DOCK8 immunodeficiency syndrome also tend to have frequent bouts of pneumonia and other respiratory tract infections. Other immune system-related problems in people with DOCK8 immunodeficiency syndrome include an inflammatory skin disorder called eczema, food or environmental allergies, and asthma.DOCK8 immunodeficiency syndrome is characterized by abnormally high levels of an immune system protein called immunoglobulin E (IgE) in the blood; the levels can be more than 10 times higher than normal for no known reason. IgE normally triggers an immune response against foreign invaders in the body, particularly parasitic worms, and plays a role in allergies. It is unclear why people with DOCK8 immunodeficiency syndrome have such high levels of this protein. People with DOCK8 immunodeficiency syndrome also have highly elevated numbers of certain white blood cells called eosinophils (hypereosinophilia). Eosinophils aid in the immune response and are involved in allergic reactions.Some people with DOCK8 immunodeficiency syndrome have neurological problems, such as paralysis that affects the face or one side of the body (hemiplegia). Blockage of blood flow in the brain or abnormal bleeding in the brain, both of which can lead to stroke, can also occur in DOCK8 immunodeficiency syndrome.People with DOCK8 immunodeficiency syndrome have a greater-than-average risk of developing cancer, particularly cancers of the blood or skin.DOCK8 immunodeficiency syndrome is also commonly called autosomal recessive hyper-IgE syndrome. However, researchers have identified several conditions that feature elevated levels of IgE and that follow an autosomal recessive pattern of inheritance. Each of these conditions has its own set of additional signs and symptoms and a different genetic cause. Some doctors consider these conditions forms of hyper-IgE syndrome, while others consider them independent disorders.