hypersensitivity types 2, 3, 4

Question 1

Type 2 HSR immune reactant

Answer 1

IgG

Question 2

Type 2 HSR antigen

Answer 2

cell or matrix associated antigen

cell surface receptor

Question 3

Type 2 HSR effector mechanism

Answer 3

complement, FCR cells (phagocytes, NK cells)

antibody alters signaling

Question 4

Type 2 HSR examples

Answer 4

Erythroblastosis fetalis (HDNB)

drug allergies

Graves Disease

Question 5

Type 3 HSR immune reactant

Answer 5

IgG

Question 6

Type 3 HSR antigen

Answer 6

Soluble antigen

Question 7

Type 3 HSR effector mechanism

Answer 7

complement, phagocytes

Question 8

Type 3 HSR examples

Answer 8

serum sickness

Question 9

Type 4 HSR immune reactant

Answer 9

Th1 cells

Th2 cells

CTL

Question 10

Type 4 HSR antigen

Answer 10

Soluble antigen

Soluble antigen

cell-associated antigen

Question 11

Type 4 HSR effector mechanism

Answer 11

macrophage activation

eosinophil activation

cytotoxicity

Question 12

Type 4 HSR examples

Answer 12

contact dermatitis, TB

chronic asthma, chronic allergic rhinitis

contact dermatitis

Question 13

Erythroblastosis fetalis (HDNB)

Answer 13

Rh negative mother, Rh positive fetus

first child minimally affected

Question 14

Erythroblastosis fetalis (HDNB) treatment

Answer 14

Rhogam (IgG anti-Rh)

Question 15

Ab2

Answer 15

against hapten modified self antigen: Ag-Ab on cells or on tissue

Type II hypersensitivity

Question 16

Ab1

Answer 16

against the hapten –may lead to soluble Ag-Ab complex

Type III hypersensitivity

Question 17

Type 3 HSR due to

Answer 17

deposition of soluble antigen/antibody complexes

Question 18

Type 3 HSR Immune complex (IC)

Answer 18

Small immune complex

circulate in blood when IC formation exceeds disposal from circulation

Reaction could systemic or localized

ex. SLE

Question 19

Type 3 HSR diagnosis

Answer 19

Results in depletion of complement in serum:

Level of serum C4 level – diagnosis

Question 20

Type 3 HSR : Serum Sickness reactions

Answer 20

Direct Immunofluorescent staining

detecting IgG deposition

“Lumpy-bumpy” pattern

Question 21

Type 3 HSR – Localized : Arthus Reaction

Answer 21

Localized deposition of IC within the skin

Question 22

Type III HSR :Lung: Hypersensitivity Pneumonitis (HP)

Answer 22

Mediated by IgG

Examples:
farmer’s lung, pigeon breeder’s pneumonitis, cheese washer’s lung, mushroom worker’s lung, laundry worker’s lung, etc

Question 23

Type 4 HSR Cell mediated

Answer 23

no antibodies involved

Question 24

Type 4 HSR Sensitization stage

Answer 24

Tho CD4 to Th1 effector cells (most common)

Naïve CD8 to cytotoxic CD8 cells (less common)

Question 25

Type 4 HSR CD4 vs CD8

Answer 25

CD4: small mol. (ex.nickel) Presented to naïve CD4 T cells CD8: (ex. poison Ivy)

Question 26

Tuberculin Reaction

Answer 26

PPD (purified protein derivative) tests exposure to Mycobacterium tuberculosis Accumulated Th1 and macrophages

Question 27

Persistent Ag

Answer 27

If antigen persists tuberculin swelling becomes granuloma

Question 28

Celiac Disease

Answer 28

Gluten from wheat Type IV hypersensitivity Clinical Features: malabsorption and diarrhea