E3 Hypersensitivity

Question 1

Hypersensitivity is a ______ immune response that is _____

Answer 1

normal
inappropriately triggered or excessive or produces undesired effects on the body

Question 1

Hypersensitivity type I, II, III = mediated by

Answer 1

B cell Plasma cell antibodies

Question 2

Hypersensitivity type IV = mediated by

Answer 2

T-cells

Question 3

Type I Key characteristics

Answer 3

-Immediate response (15-20 mins)
-Reaction occurs after being sensitized to an antigen
-Environmental (pets dander, bee stings)
-Foods (nuts, seafood, eggs)
-Medications (penicillin, contrast dye)

Question 4

Type 1 Key cells involved:

Answer 4

1. B lymphocytes
2. IgE
3. Mast cells (granulocyte)

Question 5

Talk through the Type 1 pathogenesis

Answer 5

1. The B cell becomes activated after 1st exposure
2. the Activated B plasma cell makes larges amounts of IgE
3. IgE antibodies attach to mast cells
4. Next time person is exposed to the allergen it binds to the IgE antibodies triggering the release of chemical mediators from the mast cell
5. Get physical response: Anaphylactic shock, atopic dermatitis, angioedema, Rhinitis, asthma, N/V/D, cramping

Question 6

Chemical mediators from mast cells cause what mediator activity? (4)

Answer 6

1. Potent vasodilation: stuffy nose, lower BP, Wheals on skin
2. Increased vascular permeability (Edema, Runny nose)
3. Bronchial smooth muscle contraction (Breathing difficulties, wheezing)
4. Stimulates irritant receptors (Itching aka pruritis)

Question 7

What is Type I Atopic reactions?

Answer 7

-Localized
-Inherited tendency to becomes sensitive to allergens
Ex. Allergic rhinitis, asthma, urticaria

-Most common triggers: pollen, dust, animal dander, mold

Question 8

What is Type I Anaphylaxis reaction?

Answer 8

-Systemic release of chemical mediators
-Life threatening: Bronchial constriction, vascular collapse, airway obstruction

-Most common triggers: Meds, Bee stings, Nuts

Question 9

What causes a Type II reaction?

Answer 9

-Exposure to antigen or foreign tissue/cells
-Antigens are located on cell surface
-Like giving somebody the wrong blood type or transplant pts or Erythroblastosis fetalis (RH factor)

Question 10

Key characteristics of Type II reactions?

Answer 10

1. Antigens stimulate antibody production
2. Antibodies recognize and attach to cell surface antigens (Antigen-Antibody complex)
3. Direct destruction of targeted cells that contain the antigen (Cell lysis & phagocytosis)

Question 11

Immune cells involved in Type II reactions?

Answer 11

1. IgG & IgM
2. Complement (fix foreign cells & lyse it)
3. WBCs

Question 12

What is the major problem with type II reactions?

Answer 12

The debri & clumping in small vessels reduces blood supply blocking supply to small vessels

Question 13

Type II Manifestations Transfusion Reaction

Answer 13

-Fever, chills, flushing
-Increase HR & BP
-Chest pain or back pain
-N/V
-Restlessness & Anxiety
-Headache

Question 14

What is Type III reaction?

Answer 14

-Autoimmune attack (Rhematoid arthritis)
-Low grade infection (bacteria or viruses
-Inhaled antigens from molds or contaminated plants

Question 15

Key characteristics of Type III reations?

Answer 15

1. Antigen-Antibody complexs form
2. These are deposited into tissues
3. Inflammatory response causes tissue damage

Question 16

Key immune cells involved in type III

Answer 16

1. IgG & IgM clump w/ antigens
2. Complement
3. Neutrophils & Mast cells

Question 17

Clinical manifestations of Type III depends on _____

Answer 17

where the complexes are deposited in the tissue
1. Rheumatoid arthritis (Primarily the joints)
2. Glomerulonephritis (kidney failure)
3. Systemic lupus erythematosus (skin & many organs)

Question 18

What is the main difference between Type II & III?

Answer 18

Type II-reactions occur on the cell surface and result in direct cell death or malfunction

Type III- Immune complexes are deposited into tissues and the resulting INFLAMMATION destroys the tissue

Question 19

What is Type IV Hypersensitivity?

Answer 19

-Plant oils (Poison Ivy)
-Tuberculin antigen (Positive TB skin test)
-Jellyfish sting
-Allergic reaction to jewelry
-Gluten (Crohns disease)
-Organ transplant or skin graft
-Adhesives

Question 20

Key characteristics of Type IV?

Answer 20

-Delayed hypersensitivity response 48-72 hrs)
-No antibody involvement

Question 21

Key Immune cells of Type IV?

Answer 21

1. T cells
2. Cytokines
3. Mast cells & macrophages

Question 22

Steps of a Type IV response?

Answer 22

1. Small, incomplete antigen, Hapten penetrates the skin
2. Hapten combines with human protein (APC) to form complete antigen
3. APC alerts T cells of antigen
4. T cells attack the antigen via:
   -Direct attack of the T cells
   -Release of cytokines (inflammation)
   -Macrophages (cell destruction)

Question 23

Type IV contact dermatitis manifestations

Answer 23

Redness, edema, itching, blisters

Question 24

Type IV Tuberculin hypersensitivity

Answer 24

Redness, Induration, Inflammation

Question 25

Antihistamines

Answer 25

Suppress histamine mediator activity

Question 26

Immunosuppressants (including corticosteroids)

Answer 26

Suppresses cell-mediated immunity -Anti-inflammatory

Question 27

Epinephrine MOA

Answer 27

Halts mediatory activity from mast cells

Question 28

Classification of Epinephrine

Answer 28

Vasopressor Bronchodilator Anti-asthmatic Vasoconstrictor

Question 29

Indication of Epinephrine

Answer 29

Severe allergic reaction Cardiac arrest Severe asthmatic attack

Question 30

Major side effects of epinephrine

Answer 30

Angina Arrhythmias Hypertension Tachycardia Nervousness Restlessness Tremor

Question 31

Route of epinephrine

Answer 31

All EXCEPT PO Overdose can be FATAL

Question 32

Nursing considerations for epinephrine

Answer 32

-Monitor vitals closely -Monitor for reversal of symptoms -Overdose can be fatal: heart attack -Have coworker recheck dose -Contact clinician directly after taking this