Hypersensitivity rxns

Question 1

Goodpasture syndrome

Answer 1

Type II cytotoxic HSR

Question 2

SLE

Answer 2

Type III immune complex HSR

Question 3

Tuberculin skin test

Answer 3

Type IV HSR

cell-mediated/delayed type hypersensitivity

Question 4

Type I

Answer 4

IgE Mediated

Ag x-links IgE on Mast cells and basophils –> release of vasoactive mediators

Question 5

Type II

Answer 5

Cytotoxic HSR

Ab against cell surface Ag –> complement mediated cell destruction

Question 6

Type III

Answer 6

Immune complex-mediated HSR

Ag+ab complex onto tissue –> complement –> inflam

Question 7

Type IV

Answer 7

Cell-mediated HSR/delayed

T(DTH) cells release cytokines –> activated macrophages or Tc cells –> direct cell damage

Question 8

Serum sickness (vasculitis - fibrinoid necrosis and neutrophils in small blood vessels)

Answer 8

Type III immune complex HSR - dec serum C3 nd C4 due to complement consumption
Ab to foreign proteins produced
Can occur after admin of chimeric monoclonal ab (eg rituximab or infliximab) or nonhuman immunoglobulins (eg venom antitoxins)

Question 9

Contact dermatitis (eg poison Ivy, nickel allergy)

Answer 9

Type IV HSR
cell-mediated/delayed type hypersensitivity
Mediated primarily by T lymphocytes

Question 10

Graft-versus-host disease

Answer 10

Type IV HSR
cell-mediated/delayed type hypersensitivity
Mediated primarily by T lymphocytes

Question 11

Blood transfusion reactions

Answer 11

Type II cytotoxic HSR

Question 12

Anaphylaxis (hay fever, asthma, hives, food allergies, eczema)

Answer 12

Type I IgE-mediated HSR

Question 13

Multiple sclerosis

Answer 13

Type IV HSR

cell-mediated/delayed type hypersensitivity

Question 14

Arthus reaction

Answer 14

Type III immune complex HSR

Ag-ab complexes cause the rxn. Edema, necrosis and activation of complement

Question 15

PSGN

Answer 15

Type III immune complex HSR

Question 16

Polyarteritis nodosa

Answer 16

Type III immune complex HSR

Question 17

Bee sting

Answer 17

Type I IgE-mediated HSR

Question 18

Food/drug allergies

Answer 18

Type I IgE-mediated HSR

Question 19

Myasthenia gravis

Answer 19

Type II cytotoxic HSR

Question 20

Pemphigus vulgaris, bullous pemphigoid

Answer 20

Type II cytotoxic HSR

Question 21

Rheumatic fever

Answer 21

Type II cytotoxic HSR

Question 22

Pernicious anemia, autoimmune hemolytic anemia

Answer 22

Type II cytotoxic HSR

Question 23

Graves disease

Answer 23

Type II cytotoxic HSR

Question 24

Guillain-Barre syndrome

Answer 24

Type II cytotoxic HSR

Question 25

hyperacute transplant rejection

Answer 25

Type II cytotoxic HSR (ab mediated)

Question 26

acute or chronic transplant rejection

Answer 26

Type IV cell-mediated HSR - T(DTH) cells release cytokines –> activated macrophages or Tc cells –> DIRECT cell damage
Acute (w/in 6mo): Host T-cell sensitization against graft MHC antigens
Prevent with calcineurin inhibitors
Cardio Histo: dense mononuclear lymphocytic infiltrate with cardiac damage
Chronic Renal histo: obliterative intimal thickening, tubular atrophy, interstitial fibrosis

Question 27

Candidal antigen skin test is what HSR? What does it assess the activity of?

Answer 27

Type IV cell-mediated/delayed HSR

Macrophages, CD4+ and CD8+ T lymphocytes

Question 28

Medications like opioids, radiocontrast agents, and some abx (eg vancomycin) can trigger IgE (dependent vs independent) mast cell degranulation?

Answer 28

INDEPENDENT
Activate PKA and PI3 kinase –> histamine, bradykinin, heparin, and chemotactic factor release.
Note: IgE-mediated degranulation is usually assoc with environmental exposures

Question 29

In lung transplant, the immune reaction of chronic rejection affect what part of the lung?

Answer 29

Small airways causing bronchiolitis obliterans.

Sx - dyspnea, wheezing

Question 30

Henoh-Schonlein purpura is what HSR?

Answer 30

Type III hypersensitivity - immune complex

Deposition of IgA-containing immune complexes in small vessels –> systemic vasculitis