Unit #5C – Clinical Laboratory Testing – Basic Serology/Immunology Cecile Sanders, M.Ed., MLS(ASCP)

Unit #5C – 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 #5C – 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 #5C – 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 #5C – 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 #5C – 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 #5C – 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 #5C – 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 #5C – Clinical Laboratory Testing - Basic Serology/Immunology First and Second Responses to Antigens

Unit #5C – 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 #5C – 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 #5C – 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 #5C – Clinical Laboratory Testing - Basic Serology/Immunology Agglutination of Red Blood Cells with Antibody

Unit #5C – 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 #5C – 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 #5C – Clinical Laboratory Testing - Basic Serology/Immunology Enzyme Linked Immunoassay (ELISA)

Unit #5C – Clinical Laboratory Testing - Basic Serology/Immunology Visit this website for a virtual immunology lab visit and experiment: http://www.hhmi.org/biointeractive/vlabs/immunology/index.html Try to complete the lab by following website directions! Very cool!

Unit #5C – Clinical Laboratory Testing - Basic Serology/Immunology Resources Basic Clinical Laboratory Techniques, Estridge and Reynolds, Thomson/Delmar Learning, Fifth Edition, 2008