Immunopathology

Question 1

how does a normal immune response cause disease

Answer 1

damage from inflammation in response to pathogen can exceed the damage done by the pathogen

Question 2

three infections that trigger a damaging immune response

Answer 2

1. tuberculosis
2. leprosy
3. sarcoidosis

Question 3

hypersensitivity

Answer 3

altered immune response to an antigen which results in disease or damage

Question 4

allergy (atopy)

Answer 4

hypersensitvity to environmental allergies

Question 5

autoimmunity

Answer 5

hyper sensitivity to self-antigens

Question 6

alloimmunity

Answer 6

reaction to antigens from someone else

Question 7

four types of hypersensitivity

Answer 7

Type 1: IgE mediated (anaphylaxis)

Type 2: cytotoxic reaction to self allergens (lmyastheia gravis)

Type 3: immune complex reactions (lupus)

Type 4: cell mediated (chronic transplant reaction)

Question 8

what is the difference between atopic individuals and non atopic

Answer 8

atopic individuals developed more Th1 lymphocytes vs Th2

Question 9

how does IgE cause atopy

Answer 9

IgE binds to mast cells, which degranulate and release high amounts of histamine

Question 10

where are three locations of concentrated mast cells

Answer 10

1. skin
2. airway mucosa
3. GI

Question 11

what is the physical interaction between allergens and IgE on mast cell receptors

Answer 11

IgE binds to mast cells, allergens form cross links between IgE to produce a stronger response

Question 12

what is the difference between Th1 and Th2

Answer 12

helper lymphocyte 1 produces more IgG

Th2 produces more IgE

Question 13

why do some people produce more Th2 lymphcytes

Answer 13

the mechanism isn;t know but may be related to the hygiene hypothesis

Question 14

what is the potential link between infection and allergies

Answer 14

exposure to bacterial infection increases the production of Th1, if there is no infection exposure then Th2 dominates

Question 15

what is the cut off age that a person must be exposed to certain antigens to produce more Th1 cells vs Th2 cells

Answer 15

exposure before age 2 will result in more Th1 cells, after more Th2 cells

Question 16

T/F everyone has the potential for autoimmune disease

Answer 16

True, everyone has some defective cells

Question 17

genetic risk factors for autoimmune disorders

Answer 17

family and species genetics

Question 18

civilization hypothesis

Answer 18

the formation of cities with close proximity of people and animals increased the number of epidemics and pandemics

this created an evolutionary pressure to develop a strong resistance to infection but decreased our ability to regulate immune response to self antigens and neoplasm

Question 19

autoimmune pathophysiology

Answer 19

T cell antigen receptors will bind with antigens they have a lower affinity for (like self antigens) if they are activated molecular mimicry

Question 20

molecular mimicry

Answer 20

when an autoimmune disease is triggered by an infection due to T cell cross reactivity

Question 21

two examples of molecular mimicry

Answer 21

1. strep pyogenes and rheumatic fever
2. coxsackie and type I diabetes

Question 22

antigen spreadng

what specific disease can this cause

Answer 22

when damage from an intial autoimmune response allows T and B cells to cross react with other self antigens

can cause lupus

Question 23

what are four ways to treat autoimmune disease

Answer 23

1. decrease number of lymphocytes
2. reduce production of antibodies
3. interfere with T cell activation
4. reduce cytokines (interleukin and tumor necrosis factor)

Question 24

two categories of immunodeficiency symdromes

Answer 24

1. congenital
2. acquired

Question 25

three examples of congenital immunodeficiency

Answer 25

1. isolated T cell deficiency
2. isolated B cell deficiency
3. SCIDS

Question 26

what lymphocyte does HIV attack to cause AIDs

Answer 26

CD4 helper T cells

Question 27

what are four causes of acquired immunodeficiency

Answer 27

1. AIDS
2. immunosuppressive therapy
3. inadequate nutrition
4. tuberculosis

Question 28

what are the symptoms of acute HIV infection

Answer 28

flu like symptoms that occur 2-4 weeks after exposure and last 1-4 weeks

Question 29

latent HIV infection

Answer 29

gradually decreasing CD4 counts and increasing viral load

Question 30

what are three factors that influence the length of the latent phase of AIDS

Answer 30

1. nutrition
2. other diseases
3. antiviral treatment

Question 31

what is the goal of current HIV treatment

Answer 31

prolonging the latent phase

Question 32

what is the primary indicator of the AIDS phase of an HIV infection

Answer 32

opportunisitc infection or unusualy cancer

Question 33

if an HIV positive patient is diagnosed with leukemia and receives a blood marrow transplant which decreases the amount of HIV in his blood, what happened

Answer 33

the bone marrow donation was homozygous for a chemokine receptor mutation which removed the receptor needed for HIV to bind with CD4 cells

Question 34

why is there a difference between HIV mortality in developed countries vs Africa

Answer 34

because developed nations have better nutrition, less exposure to disease, and better access to healthcare

Question 35

what is an example of an excessive immune response

Answer 35

cytokine storm

Question 36

what causes cytokine storm

Answer 36

introduction of super antigens that cause a feedback loop leading to excessive activation of cytokines and their effectors

Question 37

what are two historical instances of cytokine storm

Answer 37

1. 1918 flu pandemic
2. 2006 trail of CD28 agonist monoclonal antibodies

Question 38

why was the flu of 1918 unique?

how did most people die?

Answer 38

it was most fatal in young healthy people due to cytokine storm

either from intial cytokine storm or secondary pneumonia

Question 39

how is cytokine storm relevant to modern cancer therapy

what is the risk of this therapy?

Answer 39

patient T cells can be modified in vitro and given back to the patient to target cancer cells

it can cause a cytokine storm

Question 40

what are two sources of “super antigens”?

what are two pathologies associated with cytokine release

Answer 40

bacterial toxins or viral proteins

toxic shock and septic shock