Transcript Chapter 50
Chapter 50 Assessment of Immune Function Copyright © 2008 Lippincott Williams & Wilkins. The Immune System • Immunity: the body’s specific protective response to invading foreign agent or organism • Immunopathology: the study of diseases that result from dysfunction of the immune system • Immune disorders: see Table 50-1 – Automimmunity – Hypersensitivty – Gammopathies – Immune deficiencies: primary and secondary Copyright © 2008 Lippincott Williams & Wilkins. Central and Peripheral Lymphoid Organs Copyright © 2008 Lippincott Williams & Wilkins. Development of Cells of the Immune System Copyright © 2008 Lippincott Williams & Wilkins. Lymphocytes • B lymphocytes mature in the bone marrow; T lymphocytes mature in the thymus where they also differentiate into cells with various functions Copyright © 2008 Lippincott Williams & Wilkins. Immune Function • Natural immunity: nonspecific response to any foreign invader – White blood cell action: release cell mediators such as histamine, bradykinin, and prostaglandins, and engulf (phagocytize) foreign substances – Inflammatory response – Physical barriers, such as intact skin, chemical barriers, and acidic gastric secretions or enzymes in tears and saliva • Acquired immunity: specific against a foreign antigen – Result of prior exposure to an antigen – Active or passive Copyright © 2008 Lippincott Williams & Wilkins. Stages of Immune Response Copyright © 2008 Lippincott Williams & Wilkins. Defenses • Phagocytic immune response • Humoral or antibody response • Cellular immune response Copyright © 2008 Lippincott Williams & Wilkins. Role of Antibodies • Agglutination of antigens • Opsonization • Promote release of vasoactive substances; activation of complement system and phagocytosis • Act in concert with other components of the immune system • Types of immunoglobulins: IgA, IgD, IgE,IgG, and IgM Copyright © 2008 Lippincott Williams & Wilkins. Antibody Molecule Copyright © 2008 Lippincott Williams & Wilkins. Antigen–Antibody Binding Copyright © 2008 Lippincott Williams & Wilkins. Cellular Immune Response • B lymphocytes: humoral immunity – Produce antibodies or immunoglobulins • T lymphocytes: cellular immunity – Attack invaders directly, secrete cytokines, and stimulate immune system responses – Helper T cells – Cytotoxic T cells – Memory cells – Suppressor T cells (suppress immune response) Copyright © 2008 Lippincott Williams & Wilkins. Non-T and Non-B Lymphocytes Involved in Immune Response • Null cells – Destroy antigen coated with antibody • Natural killer cells – Defend against microorganisms and some malignant cells Copyright © 2008 Lippincott Williams & Wilkins. Complement-Mediated Immune Responses Copyright © 2008 Lippincott Williams & Wilkins. Variables That Affect Immune System Function • Age and gender • Nutrition • Presence of conditions and disorders: cancer/neoplasm, chronic illness, autoimmune disorders, surgery/trauma • Allergies • History of infection and immunization • Genetic factors • Lifestyle • Medications and transfusions: see Table 50-6 • Pyschoneuroimmunologic factors Copyright © 2008 Lippincott Williams & Wilkins. Tests to Evaluate Immune Function • WBC count and differential • Bone marrow biopsy • Humoral and cellular immunity tests • Phagocytic cell function test • Complement component tests • Hypersensitivty tests • Specific antigen–antibody tests • HIV infection tests • See Chart 50-3 Copyright © 2008 Lippincott Williams & Wilkins.