chapter 12: disorders of the immune response

Question 1

what is hypersensitivity?

Answer 1

excessive or inappropriate activation of the immune response; damaged by immune response, NOT antigen

Question 2

what is a hypersensitivity reaction?

Answer 2

abnormal immune response to not harmful substances –> tissue damage

Question 3

what are the 4 types of hypersensitivity reactions?

Answer 3

1) allergic reaction
2) cytotoxic hypersensitivity
3) immune complex hypersensitivity
4) cell-mediated delayed hypersensitivity

Question 4

what are the s/s of type 1 hypersensitivity?

Answer 4

local & atopic reactions (genetic):
1) urticaria (hives)
2) rhinitis (hay fever)
3) atopic dermatitis
4) bronchial asthma

Question 5

what are the s/s of type 1 hypersensitivity?

Answer 5

local & atopic reactions (genetic):
1) urticaria (hives)
2) rhinitis (hay fever)
3) atopic dermatitis
4) bronchial asthma

Question 6

what is the causative mechanism of type 1 hypersensitivity?

Answer 6

1) initial allergen exposure –> Ige antibody formation (fr B lymphocytes)
2) attach to mast cells
3) 2nd exposure –> antigen attach on mast cells –> histamine release
4) inflammatory response

Question 7

what are the 2 types of type 1 hypersensitivity reactions?

Answer 7

1) primary/immediate phase
2) secondary/late phase

Question 8

primary/immediate phase

Answer 8

1) mast cell degranulation releases HISTAMINE, PROSTAGLANDINS, KININS
2) vasodilation, vascular leakage, smooth muscle contraction

Question 9

secondary/late phase

Answer 9

1) lipid mediators + cytokines release LEUKOTRIENES + PROSTAGLANDINS
2) infiltration of tissue w/eosinophils, tissue destruction

Question 10

what is anaphylaxis?

Answer 10

a severe hypersensitive reaction (large mounts of chemical mediators released from mast cells into circulation quickly)

Question 11

what happens as a result of anaphylactic shock?

Answer 11

1) vasodilation –> drop in BP
2) mucosa edema
3) bronchiole constriction
4) hives
5) itching
6) skin erythema
7) vomiting
8) abdominal cramping

Question 12

what does the injection of epinephrine do?

Answer 12

1) vasoconstriction
2) increase RATE + STRENGTH of heartbeat
3) relaxes smooth bronchiole muscle

Question 13

what are the 3 mechanisms for type 2 hypersensitivity?

Answer 13

1) complement and antibody mediated cell destruction: incompatible blood transfusion, hemolytic anemia from penicillin
2) complement and antibody mediated cell inflammation: organ rejection, tissues destroyed
3) antibody mediated cell destruction/activation: graves disease (change in cell function)

Question 14

what is type 3 hypersensitivity?

Answer 14

free floating antigen + antibody

immune complexes deposit on bv walls and activates complement –> inflammation and bv damage

Question 15

what are the 2 kinds of type 3 hypersensitivity?

Answer 15

1) systemic
2) local

Question 16

what are the mechanisms of type 3 hypersensitivity?

Answer 16

1) formation of antigen-antibody complexes
2) deposition of immune complexes
3) attraction of inflammatory cells

Question 17

what is type 4 hypersensitivity?

Answer 17

cell mediated: sensitized t cells attack antigen

Question 18

what are the 2 types of type 4 hypersensitivity?

Answer 18

1) direct cell-mediated cytotoxicity
2) delayed-type hypersensitivity

Question 19

what is the difference between delayed cell-mediated cytotoxicity and delayed-type hypersensitivity?

Answer 19

cmc: ctc directly kill antigen containing cell
dth: response to soluble protein antigen (poison ivy)

Question 20

allograft

Answer 20

same species

Question 21

isograft

Answer 21

identical twins

Question 22

autograft

Answer 22

one part of body to another

Question 23

xenograft

Answer 23

between different species

Question 24

hyperacute rejection

Answer 24

patient has antibodies against transplant in them IMMEDIATELY

Question 25

acute rejection

Answer 25

SEVERAL WEEKS AFTER; unmatched antigens cause a reaction

Question 26

chronic/late rejection

Answer 26

SEVERAL MONTHS AFTER; bv’s in graft are gradually damaged

Question 27

graft vs host disease

Answer 27

when donated stem cells or bone marrow wbc attack host body

Question 28

the perfect storm

Answer 28

1) transplant must have a functional cellular immune component
2) recipient tissue: antigens foreign to donor t-lymphocytes
3) recipient tissue: compromised where it can’t destroy transplanted t cells

Question 29

how do we prevent rejection of a transplant?

Answer 29

1) match hla/mhc
2) use of immunosuppressant drugs

Question 30

autoimmune disease

Answer 30

self-tolerance breaks down
immune system attacks self-antigens –> destroys body tissues

Question 31

immunodeficiency

Answer 31

loss of part or all function of immune system; acute or chronic

Question 32

what are the two kinds of immunodeficiency?

Answer 32

1) primary: genetic, congenital disorders
2) secondary/aquired: malnutrition, drug induced, caused by infection (hiv)

Question 33

what are some effects of immunodeficiency?

Answer 33

1) opportunistic infections
2) arise from normal flora
3) difficult to treat
4) increased risk of cancer

Question 34

treatments of immunodeficiency disorders

Answer 34

1) antibody replacement
2) bone marrow/thymus replacement

Question 35

hiv

Answer 35

human immunodeficiency virus: transmitted by body fluids (sexual contact, breast milk, blood-to-blood contact)

Question 36

phases of hiv

Answer 36

1) primary infection: s of systemic infection are flu-like, antibodies against hiv appear (1-6 mo)
2) latency phase: virus replication, t helper cell count falls
3) overt aids: t helper cell count <200 cells

Question 37

associated illnesses of aids

Answer 37

1) opportunistic infections (respiratory, gastrointestinal, nervous)
2) malignancies: kaposi sarcoma, non-hodgkins
3) wasting syndrome
4) metabolic disorders