Hypersensitivity & Autoimmune diseases

Question 1

Hypersensitivity

Answer 1

overly sensitive, inappropriate response, more extreme

Question 2

Types of hypersensitivity

Answer 2

Type I-IgE-mediated
Type II-tissue mediated or specific
Type III-immune-complex mediated
Type IV-cell mediated

Question 3

Type I hypersensitivity

Answer 3

IgE-mediated
Allergens
Sensitization
Symptoms due to vasoactive amines
-itching, bronchiospasms, laryngospasms, runny nose, red eyes, conjunctivitis
Anaphylaxis, food allergy, environmental allergy, wasp/bee, drugs

Question 4

Type II hypersensitivity

Answer 4

Tissue-specific
Ab-Ag complex forms in tissue
formation of Aschoff bodies (rheumatic fever)
phagocytosis, inflammation
Myasthenia gravis, Graves disease

Question 5

Type III hypersensitivity

Answer 5

immune-complex formation
Ab-Ag complex forms in blood, circulates, gets stuck in filtration (kidney, blood vessels, joints)
complement activation, triggers inflammation
Glomerulonephritis, arthritis, vasculitis

Question 6

Type IV hypersensitivity

Answer 6

Cell-mediated (CD8 or CD4, phagocytic cells, tissue destruction)
Crohn’s, contact dermatitis, multiple sclerosis, DM Type I, Hashimoto disease, RA, Ciliac disease

Question 7

autoimmunity

Answer 7

breakdown of self-tolerance mechanisms

triggers: genetics, environmental

Question 8

Systemic Lupus Erythematosus

Answer 8

Four types (systemic, induced, fetal cutaneous)
S&S:
-acute necrotizing vasculitis
-joint swelling
-skin erythema
-CNS involvement-vasculature that profuses CNS also effected
-malar rash
-Glomerulonephritis
-type III hypersensitivity

Question 9

Rheumatoid Arthritis

Answer 9

Type IV hypersensitivity
Etiology
-Arthritogenic agent-believed to be collage II
Pathogenesis
-CD4 cells in joints activate B-cells, macrophages, and endothelial cells 
Morphology
-synovial destruction
-pannus
-ankylosis
-rheumatoid nodules
-blood vessel obstruction