Type II Immunopathology

Question 1

Describe Type I immunopathology.

Answer 1

Symptoms or pathology due to IgE and Th2-mediated events

Question 2

Describe Type II immunopathology

Answer 2

Pathology due to IgG, IgM, or IgA antibody causing harm to self. Also includes Type V stimulatory antibodies.

Question 3

Describe Type III immunopathology

Answer 3

Formation of immune complexes which are trapped in basement membranes of blood vessels and activate complement leading to vasculitic inflammation

Question 4

Describe Type IV immunopathology

Answer 4

Pathologic outcomes of normal or abnormalT cell responses including both helper and cytotoxic cells

Question 5

What is chronic frustrated immune response?

Answer 5

ADAPTIVE immune response to try to get rid of antigens that never can.

Question 6

Give examples of things that can cause chronic frustrated immune responses.

Answer 6

Normal gut flora (Crohn’s Disease)
Skin flora (Psoriasis)
Chemicals (Chronic Beryllium disease)
Gluten (Celiac Disease)

Question 7

What are the three mechanisms of tissue damage caused by antibodies?

Answer 7

1. Neutralization
2. Complement-mediated damage
3. “Stimulatory hypersensitivity”

Question 8

What is one example of antibody mediated immunopathology that causes neutralization?

Answer 8

Neutralizing anti-interferon (IFN)-gamma autoantibodies found in adults of Southeast Asian decent.

Associated with disseminated nontuberculous mycobacteria

Question 9

What are three ways in which complement can mediate damage?

Answer 9

1. Create pores in cells
2. Phagocytosis (opsonizing)
3. Phagocytes’ lysosomal enzymes and ROS

Question 10

Give an example of stimulatory hypersensitivity

Answer 10

Graves disease

Question 11

Describe Graves disease

Answer 11

Long-acting thyroid stimulator that binds to thyroid stimulating hormone receptor and stimulates the thyroid.

Hyperthyroidism

Question 12

What are the symptoms of myasthenia gravis?

Answer 12

Progressive muscle weakness

Question 13

What is the target for autoantibodies in myasthenia gravis?

Answer 13

AChR the alpha subunit

Question 14

What happens after the autoantibodies in myasthenia gravis bind to AChR?

Answer 14

Complement and neutrophil mediated destruction

Question 15

How is Aire implicated in myasthenia gravis?

Answer 15

• Mutated CHRNA1 gene of AChR is mutated
• Aire transcription factor cannot bind too gene
• Protein is not expressed in patients’ thymus
• No clonal deletion of Th cell against AChR
• Tfh can activate B cell»Plasma cell antibodies agains AChR

Question 16

What are the treatments of myasthenia gravis?

Answer 16

Thymectomy
Immunosuppression
Neostigmine-related drugs (increase effectiveness of ACh)
IVIg

Question 17

What do the autoantibodies in Goodpasture syndrome bind to?

Answer 17

Collagen IV found in the basement membrane of the lungs and kidneys

Question 18

What Goodpasture patients usually get pneumonitis with pulmonary hemorrhage?

Answer 18

Smokers

Question 19

Does Goodpasture syndrome usually cause a linear or lumpy-bumpy immunoflorescent stain??

Answer 19

Linear. Antibodies directly against BM

Question 20

What is Dressler Syndrome?

Answer 20

Autoantibodies that react to the heart after a heart attack or heart surgery.

Question 21

What are the symptoms of Dressler syndrome?

Answer 21

Cardiac pain
Fever
Malaise
Pericardial effusion

Question 22

What bacteria causes rheumatic heart disease?

Answer 22

Streptococcus

Question 23

What is the self antigen in rheumatic heart disease?

Answer 23

Laminin found on the endocardium and valves

Question 24

What cells mediate the destruction of the cardiac cells?

Answer 24

Neutrophils

Question 25

What is the pathophysiology of autoimmune thrombocytopenic purpura (ATP)?

Answer 25

Autoantibodies bind to platelets and are sequestered by the spleen.

Question 26

What are some of the common causes of autoimmune hemolytic anemia (AIHA)?

Answer 26

Viral infections
Autoimmune syndrome
Cancer
Drugs

Question 27

Name some drugs that can cause AIHA.

Answer 27

Penicillin
Methyldopa
Chlorpromazine
Quinidine

Question 28

What autoimmune disorder can cause AIHA?

Answer 28

Paroxysmal cold hemoglobinuria (PCH)

-binding at 15 degrees Celcius

Question 29

Hyperthyroidism caused by stiumulatory autoimmunity to the TSH receptor on thyroid cells causes what disorder?

Answer 29

Graves Syndrome

Question 30

Hypothyroidism resulting from autoantibodies to thyroglobulin and thyroid peroxidase resulting in inflammatory and destruction causes what disorder?

Answer 30

Hashimoto disease

Question 31

Hashimoto disease is found in what patient population?

Answer 31

Females for the most part (5/6)

Question 32

Name some mechanisms of loss of tolerance.

Answer 32

1. Hybrid (foreign + self) antigen formulation
2. Emergence of forbidden clone
   - -Ex: Myasthenia gravis
3. Cross-reaction
   - -Rheumatic fever
4. Passive antibody
   - -Mismatch transfusion
5. Innocent bystander
   - -Drug bound to RBC
6. Sequestered antigen
   - -Mumps&raquo_space;>Infertility
7. Failure of regulatory mechanisms
   - -T cells are not balanced

Question 33

What is the difference between direct and indirect test for immunofluorescence?

Answer 33

Direct- Sample of the patients tissue with autoantibodies is incubated with goat or rabbit antibody to human IgG tagged with fluorescein

Indirect- Nomal tissue sample (not patient derived) is incubated with patients serum. Then incubated with labeled anti-IgG