Chapter 10 Alterations in Immune Function Notes The purpose of the immune system is to defend the body against foreign antigens.The disorders can be divided into two general categoriesExcessive Immune Responses – Disorders in which the immune system is over functioning or hyperfunctioning, such as autoimmunity and hypersensitivity disorders.Autoimmune diseases are complex, multifactorial chronic diseases that occur in response to polygenetic as well and environmental factors.3- 10% of population.Deficient Immune Responses - include disorders in which the immune system fails to respond to provide protection and is ineffective because of disease- causing genotype tosecondary/acquire disfunction.Ex: DiGeorge Syndrome, IgA deficiency, Severe combined immunodeficiency disorder (SCID)Excessive Immune ResponsesDefinition.What happensAutoimmunity Etiological cause of abnormal excess immune responses towards self-tissue. Immune system attacks own tissue Through type 2 (cytotoxic) and 3 (immune complex). Failure of self tolerance Genetic factors: play a role in the development of autoimmune disorders.Gender: females are at higher risk to develop autoimmunity than makes.Those with genetically low levels of tumor necoris factor a(TNF) and high levels IL-10 may be more tolerant than those with normal levels.HLA genes of MHC located on chromosome 6p21 are associated with autoimmunity because the MHC gene region is associated with polymorphism.HlA-b27 phenotype linkage with ankylosing spondylitisAddison disease is associated with HLA-DR3Juvenile rheumatoid arthritis is associated with HLA-DR5PTNP22- diabetes, ARTHRITIS, SLE, Graves’ disease, and Crohns disease ENVIRONMENTAL: VIRUSES BACTERIA, foods, pharmaceutical agents, smokingPharmacotherapies: Corticosteroids, Purine analogs,Hypersensitive disorders Mechanisms of injury, howinjury occurs, may or may not involve autoimmunity. Type 1, 2, 3, 4.Type 1,2,3 are mediated by antibodies.Type I Hypersensitivity: genetic linkage
Is a abnormal immune response triggered, excessive, or produces undesirable effects on the body.to IgE response to an allergen and the general ability to produce an IgE antibody response. Known as immediate hypersensitivity. Usually lasts for 15 to 30 minutes after exposure to antigen. IgE are produced by specialized plasma B cells and circulates in very small amounts within the blood. Mast cells have receptors for H1 that causes vasodilation, itching, mucous secretion. H1 receptors are on macrophages and monocytes, H2 receptors have opposing effect, H 4 receptors are found in the brain spinal cord and sensory neurons, and H4 receptors are found on immune system cells like dendritic cells, eosinophils, T cells, monocytes, macrophages, and NK cellsAnaphylaxis: extreme allergic reaction.