Immunity

Question 1

Immune System

Answer 1

• Eliminates foreign substances (i.e. antigens) introduced into the body
• Intended to prevent the harmful effects caused by foreign substances

Question 2

Components of the immune system

Answer 2

1. Nonspecific immune system

2. Specific immune system

Question 3

Nonspecific immune system

Answer 3

 Prevents initial invasion by the antigen
o Physical barriers
o Phagocytosis

Question 4

Cell-mediated immune response

Answer 4

o Involves the production on Ag-specific T-lymphocytes- destroy body cells that are infiltrated by invader
o Cytotoxic cells are produced that destroy Ag-infected cells

Question 5

Immunization

Answer 5

 The administration of an Ag to induce resistance to infection
Stimulate humoral immunity, make antibodies and memory cells

Question 6

Immunization Can be achieved by

Answer 6

Exposure to infectious disease
 	Vaccination
o	Killed/Inactivated 
o	Modified Live/Attenuated 
o	Recombinant/Genetically Engineered

Question 7

Temporary immunization can be achieved by antibody administration

Answer 7

Passive immunity

Immunoglobulin injection

Question 8

Anaphylaxis

Answer 8

Binding of an Ag to IgE covered mast cells or basophils leading to the release of chemical mediators (e.g. histamine)
-Ag’s can be vaccines, drugs, pollens/molds, food ingredients, insect bites

Question 9

Clinical signs of anaphylaxis

Answer 9

Shock, hives, nasal/ocular discharge, asthma, vomiting, diarrhea, dermatitis

Question 10

Immunodeficiency

Answer 10

o Lack of the immune system components necessary to provide immunity
o Example: Combined immunodeficiency in horses FIV, HIV

Question 11

Autoimmune diseases

Answer 11

Antibodies against the animal’s own normal cells are formed causing their destruction

Question 12

Immune system response and diagnostic tests for infectious diseases

Answer 12

 Most diagnostic tests are based on the humoral immune system’s response to Ag
 Serology the science of detection and measurement of Ab’s or Ag’s
 Various serologic tests have been developed for domestic animals- These tests make the Ag/Ab reaction visible to the naked eye if the sample is positive

Question 13

Types of serologic tests for infectious diseases

Answer 13

 Enzyme-Linked Immunosorbent Assay (ELISA)
 Latex Agglutination
 Immunodifusion

Question 14

ELIZA test

Answer 14

Based on antibody-antigen interaction
Allows for easy visualization of results
In-house tests allow for immediate results
Giardia and Parvo are fecal tests
Blood tests can usually be run on whole blood (anticoagulant), or serum or plasma
Can test for pathogen antigen or host antibody

Question 15

Snap Heartworm Test

Answer 15

o Detects Dirofilaria immitis antigen in feline and canine whole blood, serum, or plasma
o Enzyme immunoassay – conjugate reacts with reagents in the test device
o Color development in the antigen spot is proportional to amount of antigen in blood
• Components must be at room temperature
• Serum, plasma, or anticoagulated whole blood (heparin or EDTA)

Question 16

Antigenic substances include

Answer 16

Bacteria, 
viruses, 
toxins, 
transplanted tissue, 
pollen, 
food proteins

Question 17

Phagocytosis

Answer 17

ingestion and destruction of antigen by WBC’s in the body

Question 18

Humoral immune system

Answer 18

floating around in the fluid (all fluids were called humors)
• Involves the production of Ag-specific antibody by B-lymphocytes
• Antibody (immunoglobulin) classes- gammaglobluins : IgG, IgM, IgA, IgE
• Antibodies remove extracellular Ag’s

Question 19

Examples of Autoimmune diseases

Answer 19

Examples:
•	Autoimmune hemolytic anemia (AIHA)
•	Autoimmune thrombocytopenia 
•	Pemphigus
•	Myasthenia gravis