Unit #5C – Clinical Laboratory Testing – Basic Serology/Immunology

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

2. 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)

3. 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

4. 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”

5. 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)

6. 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

7. 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

8. 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

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

10. 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)

11. 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)

12. 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

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

14. 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)

15. 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.

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

17. 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!