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:
Try to complete the lab by following website directions! Very cool!