Exam 2: Ch 16 Flashcards Preview

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Flashcards in Exam 2: Ch 16 Deck (82):
1

4 types of hypersensitivity disorder

type 1: allergic reactions

type 2: antibody-mediated disorders

type 3: immune complex mediated disorders

type 4: cell mediated disorders

2

type 1: allergic reactions 2 subtypes

local (atopic) reactions

systemic (anaphylactic) reactions

3

when do type 1 allergic reactions begin

almost immediately after exposure to allergen

4

allergens are usually what type of molecule

proteins

pollen, food, animal dander, dust mites

5

immune system response to type 1: allergens

processed by macrophages

T helper cells (CD4) release cytokines which stimulate plasma cells to make and release IgE antibodies

IgE binds to mast cells (sensitized like memory cells)

hours later, esinophils recruited

6

mast cells that have been sensitized...

degranulate on subsequent exposure

release histamine, cytokines, etc

7

symptoms of type 1: allergic rxns

vasodilation

smooth muscle contraction

8

anaphylactic reaction (systemic)

can produce shock

must stabilize airway and give epi

prevent exposure, wear bracelet

9

local (atopic) allergic rxn examples

hives

dermatitis

hay fever

10

esinophils can also fight off _____

parasites

11

type 2: Ab mediated description

IgG or IgM mediated

directed against antigens on cell surfaces or in conn. tissue

12

3 types of type 2: Ab mediated

complement & Ab mediated cell destruction

complement & Ab mediated inflammation

Ab mediated cell dysfunction

13

complement & Ab mediated cell destruction

Ab coat abnormal cells

cells killed by complement system or phagocytosis

ex. blood transfusion rxn

14

complement & Ab mediated inflammation

Ab coat abnormal cells or react with extracellular proteins

complement activated --> chemotaxic factors

monocytes and neutrophils recruited

causes inflammation and tissue damage

15

examples of complement & Ab mediated inflammation

Goodpasture syndrome

glomerulonephritis and pulmonary hemorrhage from basement memb. inflammation

16

Ab mediated cell dysfunction

Ab inactivate/destroy or activate cells (receptors)

ex. Graves disease: Ab activate TSHr (hyperthyroidism)

Myasthenia Gravis: Ab inactivate AChr

17

type 3: immune complex mediated disorders

antigen-Ab complexes form in circulation and activate complement

inflammation and damage within blood vessels

ex. allergic rxns to drugs or food

18

type 4: cell mediated disorders

antigen presented to CD4 by APC

CD4 activates CD8 --> kill target cells w/ antigen

common response to intracellular parasites and part of autoimmune diseases

19

type 4 can also produce...

a delayed hypersensitivity rxn

CD4 secretes cytokines that recruit lymphocytes

inflammation results

ex. contact dermatitis, pneumonitis from inhaled antigens

20

HLA/MHC

human leukocyte antigen/major histocompatibility complex

antigens on surface of all body cells, individual specific

21

transplantation

taking tissue from 1 person and giving it to another

22

rejection

recipient's (host) immune system sees donor HLAs as foreign and attacks the graft

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autologous graft

donor & recipient are the same person

24

syngenic graft

donor and recipient are identical twins

25

allogenic graft

donor and recipient differ genetically

26

allograft rejection

host immune system recognizes graft antigens on organ surface or APCs

activates CD4 --> CD8 --> type 4 rxn

Ab may contribute

27

3 patterns of rejection

hyper acute

acute

chronic

28

hyper acute rejection

almost immediate type 3 rxn

results from preexisting Ab from previous blood transfusions

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acute rejection

within months

involves T cells

30

chronic rejection

may involve fibrosis

cytokines

takes time

31

graft vs. host disease

most common following bone marrow transplant

graft attacks the host's organs

host's immune system compromised and can't destroy graft

produces rash, GI sloughing, organ (liver) failure

32

what is an autoimmune disease

when the immune system attacks self

organ-specific or systemic

33

examples of organ-specific autoimmune diseases

thyrotoxicosis (Graves): TSH

pernicious anemia

Hashimoto thyroiditis

Addison's disease

34

examples of systemic autoimmune diseases

lupus

scleroderma

rheumatoid arthritis

ulcerative colitis

35

immune tolerance

immune system "tolerates" self, only attacks foreign antigen

develops in fetal development

36

central tolerance

T cells reacting against self are eliminated in thymus

37

peripheral tolerance

immune cells including B cells that react against self are eliminated in the lymph organs

38

genetic susceptibility to autoimmune disease

families with specific HLAs prone

not everyone with HLA type gets disease, mechanism unclear

39

environmental factors of autoimmune disease (mechanisms)

T cells active against self when co-stimulators present

self-antigens that were held during development are released, prompting an immune response

molecular mimicry: microbe has antigen similar to self

super-antigens on microbes stim T cells w/o processing and binding to normal receptors

40

diagnosis of autoimmune disease

assay for Ab in patients with symptoms (fever, rash, inflammation)

41

treatment of autoimmune disease

steroids

immunosuppressants

42

primary immunodeficiency disorders

inherited or congenital -- most recessive and x-linked

some traced to cytokines/signaling pathways

warning signs: multiple infections

many types

43

some signs of primary immunodeficiency disorders

8+ ear infections in a year

2+ sinus infections in a year

2+ pneumonia in a year

2+ deep-seated infections

2+ months on antibiotics that doesn't help

44

b-cell immunodeficiency

most common primary immunodeficiency

stem cells --> pre-B in marrow --> lymph tissue maturation

mature B cells make specific Ab --> plasma cells when stim

45

transient hypogammaglobuinemia of infancy

delayed production of IgG --> multiple respiratory infections

usually resolves spontaneously

(infants protected by maternal IgG until 6mo of age)

46

X-linked agammaglobulinemia

recessive, more common in males

bruton tyrosine kinase needed for pre-B maturation

symptoms at 6-9mo, respond poorly to antibiotics

Rx: IVIG (intravenous immunoglobulin)

47

common variable immunodeficiency

differentiation of B cells to plasma cells blocked (affects 1+ types)

symptoms in teens to early adult

48

immunoglobulin G deficiency

respiratory infections

IVIG

49

T-cell immunodeficiency

more severe than B-cell deficiency

DiGeorge syndrome (thymic hypoplasia)

50

DiGeorge syndrome (thymic hypoplasia)

T-cell deficiency

developmental defect of thymus and parathyroid

associated w/ facial and cardiac defects

extent of defect variable

51

SCID severe combined immunodeficiency disorders

most x-linked and recessive, more common in males

survival rate w/o bone marrow transplantation

1 type: T, B, NK cells deficient

2nd type: T, NK, CD4 cells deficient, B cells elevated, Ab production abnomal,

52

AIDS is caused by ___ infection

HIV

34m ppl living, 1.7m died, 2.5m get it

most new infections in underdeveloped countries

sub-sarahan africa, racial minorities in US

recognized in 1981, IDed in 1984

53

transmission of HIV

sexual contact: body fluid contact w/ mucosa or open sore

blood to blood contact: shared needles

perinatal transmission: in utero or during delivery

occupational

54

seroconversion

when HIV Ab develop and become detectable

1-6 mo after infection

55

HIV virus structure

HIV 1 & 2 (1 most common in US & europe, 2 in africa)

retrovirus (RNA)--core surrounded by lipid envelope

2 copies of RNA in core, p24 protein (target of Ab screen) and p17 protein (surrounds core)

3 enzymes: Rev. transcriptase, integrase, protease

56

enzyme order HIV

reverse transcriptase (transcribes RNA into dsDNA)

integrase (dsDNA integrated into CD4 genome)

(transcription, translation happens)

protease (breaks polyprotein into pieces)

new virus built from pieces and HIV released from cell

57

HIV infects which type of cells

CD4--binds to receptors and other surface molecules (CCR5)

requires glycoproteins gp120, gp41

virus memb. fuses to CD4 so RNA and enzymes can enter cell

58

HIV replication starts at...

site of infection

many CD4 cells infected by day 10

people with HIV generally asymptomatic until CD4 count falls

59

classification of HIV phases

HIV+ said to have AIDS if:

CD4 count less than 200cells/microliter

or have an AIDS-defining illness

60

HIV stage 1 and 2 and 3 (AIDS)

T cells greater than or equal to 500

2: T cells between 200-499

3: T cells less than 200

61

primary HIV infection

mono-like symptoms (fever, fatigue, myalgia, sore throat)

viral replication rapid

CD4 count falls

treatment beneficial

62

latent period of HIV infection

viral load is low, but CD4 count falls over time

lymphadenopathy develops

63

overt AIDS

viral load climbs

CD4 count less than 200/ul or AIDS-defining illness

opportunistic infections and cancer develops

64

what is the leading cause of death for AIDS

TB

65

respiratory manifestations of AIDS

pneumocystis pneumonia (fungal spores)

common pneumonia like strep, pseudomonas, H flu

PCP--less common since HAART

mycobacterium TB: multiple drug resistant strains

66

GI manifestations of AIDS

esophageal candidiasis

herpes simplex (esophageal)

gastroenteritis: protozoal or bacterial (stool culture)

67

NS manifestations of AIDS

HIV-associated neurocognitive disorders (HAND)
cognitive and motor impairment

toxoplasmosis: parasitic brain infection
antibiotics

68

Kaposi sarcoma

endothelial cell malignanacy in AIDS

opportunistic cancer linked to herpes

lesions on skin and in mouth, in internal organs (lungs)

HAART may be effective

69

non-hodgkin lymphoma

AIDS cancer

may undergo remission with HAART

70

cervical and anal carcinoma

AIDS cancer

from HPV

71

wasting syndrome

AIDS

weight loss, diarrhea, chronic weakness, fever

Rx: appetite stimulants

72

3 metabolic disorders associated with AIDS

insulin resistance

hypercholesterolemia/triglyceridemia

lipohypertrophy

might need to switch anti-retroviral drugs

73

insulin resistance (AIDS)

higher among those with HIV

medications may contribute to development

74

hypercholesterolemia/triglyceridemia

HIV and medications contribute to development

monitor lipids closely

use statins with caution

75

lipohypertrophy

buffalo hump right below back of neck

76

prevention of HIV infection

condoms

avoid recreational drug use, sharing needles

routine screening

education

77

diagnosis of HIV

HIV Ab test: ELISA + western blot if initial is ( + )

western blot is more specific (less false pos)

oral swab for at home use (both ELISA and western blot)

PCR: detects HIV, not Ab (used earlier)

78

HAART

combination of 2 or 3 anti-retroviral drugs

reverse transcriptase inhibitors

protease inhibitors

entry inhibitors

integrase inhibitors

79

reverse transcriptase inhibitors

block RNA --> DNA conversion

block elongation of DNA by adding fake nucleotide or inhibit enzyme

80

integrase inhibitors

prevent integration of viral cDNA into cell genome

81

protease inhibitors

block cleavage of viral proteins by binding and inhibiting enzyme

82

entry inhibitors

prevent HIV from binding to or entering CD4 cells