Unit #6C – Clinical Laboratory Testing – Basic Serology/Immunology Cecile Sanders, M.Ed., MT(ASCP), CLS (NCA)

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology  The Immune System –Complex system of tissues, cells, cell products, & biologically active chemicals –Produces an Immune Response –Defense mechanism against foreign substances called “antigens” (ag)

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology  Natural Resistance vs. Specific Immunity –Natural Resistance  Includes physical barriers (skin, mucous membranes, etc.), white blood cells like neutrophils, and proteins that cause inflammation  Non-specific  Does not require exposure to an antigen

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology –Specific Immune Response  Recognition – recognizes foreign antigens and distinguishes them from “self”  Specificity – reacts with a specific antigen without reacting with others  Memory – “anamnestic response”

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology  Cells, Tissues, and Organs of Immune System –Lymphocytes – B Cells and T Cells –Primary Lymphoid Organs = Bone Marrow and Thymus (glandular tissue located at the base of the sternum)

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology –Secondary Lymphoid Tissue = Spleen, Lymph Nodes, Appendix, and Tonsils  Humoral Immunity –B Lymphocytes produce antibodies against specific antigens –Good protection against bacteria, toxins, and circulating antigens  Cell-Mediated Immunity –T Lymphocytes protect against viruses, fungi, tumor cells, and intracellular organisms

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology  Immunoglobulins (Ig) –Also called “antibodies” (ab) –Named by placing the prefix anti before the name of the antigen with which the antibody reacts

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology  Primary vs. Secondary Antibody Response –Primary occurs after first exposure to an antigen –Secondary Response  Sometimes called “anamnestic response”  Lymphocytes remember the antigen  Immunizations or vaccinations (such as for measles, tetanus, etc.) are effective because of the Secondary Response –Seroconversion = when an antibody is detectable in patient who has previously tested negative for the antibody

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology First and Second Responses to Antigens

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology  Categories of Conditions Associated with Immune System Abnormalities –Autoimmune Disease (RA, Lupus, Juvenile Type I Diabetes, Myasthenia Gravis) –Hypersensitivies (Hay fever, Asthma, Dermatitis) –Malignancies (Lymphomas, Leukemias, Multiple Myeloma)

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology  Categories of Conditions Associated with Immune System Abnormalities (cont’d) –Acquired Immunodeficiencies (Infections, Systemic Disease, Malignancies, Reactions to Drugs, Irradiation) –Congenital Immunodeficiencies (DiGeorge Syndrome, Aggamaglobulinemia, SCID – Severe Combined Immune Deficiency)

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology  Tests of Immune Function –Based on Antigen-Antibody Reactions  May be qualitative (positive or negative)  May be quantitative (Titer = Reciprocal of the highest dilution of patient’s serum showing a positive reaction with antigen) –Principles of Immunological Tests  Agglutination and Agglutination Inhibition – visible clumping of cells or particles due to their reaction with an antibody

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology Agglutination of Red Blood Cells with Antibody

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology –Principles of Immunological Tests (cont’d)  Precipitation – formation of an insoluble complex when a specific antibody is reacted with a soluble antigen (usually in a gelatin- like substance)

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology –Principles of Immunological Tests (cont’d)  Labeled Antibody Techniques – Molecules (labels) are attached to the antibodies, producing a visible reaction. Labels may be dyes, enzymes or radioisotopes.

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology Enzyme Linked Immunoassay (ELISA)

Unit #6C – Clinical Laboratory Testing - Basic Serology/Immunology Visit this website for a virtual immunology lab visit and experiment: /immunology/index.html /immunology/index.html Try to complete the lab by following website directions! Very cool!