Lecture 7: Approach to Hypersensitivity/Autoimmune Topics

Question 1

What antibody mediates a type I hypersensitivity reaction?

Answer 1

IgE cross-linking on mast cell/basophil surfaces

Question 2

What is the main mediator of a type I hypersensitivity reaction?

Answer 2

Histamine

Question 3

What are some symptoms of a type I hypersensitivity reaction?

Answer 3

• Urticaria (hives)
• Rhinitis
• Wheezing
• Diarrhea
• Vomiting
• Hypertension
• Anaphylaxis

Question 4

What are examples of type I hypersensitivities?

Answer 4

• Pollen allergies
• Dust mite allergies
• Bee sting

Question 5

What antibody mediates a type II hypersensitivity reaction?

Answer 5

IgM or IgG destroy cells

• opsonization
• complement mediated lysis
• cytotoxicity

Question 6

What are examples of type II hypersensitivities?

Answer 6

• ABO mismatch
• Grave’s disease
• Myasthenia Gravis

Question 7

What is the cause of Myasthenia Gravis?

Answer 7

Antibodies to acetylcholine receptor, preventing acetylcholine to bind

Question 8

What are symptoms of Myasthenia Gravis?

Answer 8

• Ptosis
• Fatigue
• Blurry vision

Question 9

What mediates a type III hypersensitivity reaction?

Answer 9

Antigen-antibody complex that activates complement and neutrophil infiltration of tissue

Question 10

What are some symptoms of a type III hypersensitivity reaction?

Answer 10

• Fever
• Urticaria
• Generalized lymphadenopathy
• Arthritis
• Glomerulonephritis
• Vasculitis

Question 11

What are examples of type III hypersensitivities?

Answer 11

• Systemic Lupus Erythematosus
• Rheumatoid Arthritis
• Farmer’s lung

Question 12

What mediates a type IV hypersensitivity reaction?

Answer 12

Antigens activating T cells

-symptoms appear 48-96 hours after exposure

Question 13

What are examples of type IV hypersensitivities?

Answer 13

• Poison Ivy

- PPD testing for tuberculosis

Question 14

Rheumatoid arthritis is a systemic infalmmatory disease that affects what?

Answer 14

Synovial membranes

-granulation tissue develops in joint spaces and erodes into articular cartilage and bone

Question 15

What are signs of rheumatoid arthritis?

Answer 15

• Morning stiffness
• joint swelling
• warmth and erythema
• decreased ROM

Question 16

What parts are most affected by rheumatoid arthritis?

Answer 16

• PIP
• MCP
• wrist
• knees
• ankles

Question 17

In rheumatoid arthritis, what time for deformities are found in bilateral ring finger?

Answer 17

MCP joint - boutonniere

Question 18

Does rheumatoid arthritis get better throughout the day or worse?

Answer 18

Gets better (osteoarthritis gets worse)

Question 19

What is juvenile idiopathic arthritis?

Answer 19

Collagen vascular disorder in one or joints for more than 6 weeks in patients under age 16

Question 20

What are symptoms of juvenile idiopathic arthritis?

Answer 20

• Large joints
• Iridocycylitis (inflammation involving ciliary body)
• Uveitis (inflammation of middle layer of eye)
• Can have fevers

Question 21

Who is at highest risk of systemic lupus erythematosus?

Answer 21

Females (especially African American women)

Question 22

What is systemic lupus erythematosus?

Answer 22

Type III hypersensitivity

• immune system attacking self body
• can affect joints, skin, kidneys, blood cells, brain, heart, and lungs

Question 23

What are some of the symptoms of systemic lupus erythematosus?

Answer 23

• Pleuritis, pericarditis, myocarditis
• Oral aphthous ulcers
• Arthritis
• Photosensitivity
• Anemia
• Butterfly rash
• Discoid rash

Question 24

What will test positive in patients with systemic lupus erythematosus?

Answer 24

Positive ANA

Positive anti-dsDNA, anti-SM, antiphospholipid

Question 25

What can differentiate systemic lupus erythematosus and rheumatoid arthritis?

Answer 25

• Erosions common in RA
• Morning stiffness lasts only minutes in SLE
• Arthritis not too common in RA
• Untreated RA: high levels of ESR and CRP

Question 26

What is psoriasis?

Answer 26

Chronic, hyperproliferative inflammatory disorder characterized by thick adherent scales

Question 27

How does psoriasis present?

Answer 27

• Mild pruritus
• Pink plaques
• Bilateral
• Nail pitting

Question 28

What is multiple sclerosis?

Answer 28

Demyelinating disease in which the immune system attacks protective covering of nerves

Question 29

How does multiple sclerosis present?

Answer 29

• Vision changes
• Vertigo
• Weakness
• Numbness/tingling/pain
• Urinary incontinence
• Lhermitte’s sign: electrical sensation running down spine and lower extremities with neck flexion

Question 30

When do T cell immunodeficiencies present?

Answer 30

First 3-4 months of life

Question 31

What is an example of a T cell immunodeficiency?

Answer 31

DiGeorge

• absent thymus
• hypoparathyroidism
• hypocalcemia

Question 32

When do B cell immunodeficiencies present?

Answer 32

First 6 months

-mostly sinopulmonary and GI infections

Question 33

What is an example of a B cell immunodeficiency?

Answer 33

Common Variable Immunodeficiency

Question 34

What is SCID?

Answer 34

Absence of both T and B cells

• onset around 3 months
• diarrhea, pneumonia, otitis, sepsis

Question 35

What is Chediak-Higashi syndrome?

Answer 35

Rare autosomal recessive lysosomal disorder

• problem with phagocytosis
• increased sinopulmonary and soft tissue infections

Question 36

What are symptoms of HIV/AIDs

Answer 36

Flu-like:

• Myalgia
• Fever
• Anorexia
• Headache
• Fatigue
• Pharyngitis