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Flashcards in ID 13 Deck (52):
1

HBV transmission mnemonic

Parenteral (blood)
sexual (baby-making)
perinatal (birthing)

2

HDV transmission

same as HBV

3

most common HEV source

waterborne

4

incubation
HAV -
HBV -
HCV -
HDV -
HEV -

HAV - short (weeks)
HBV - long (months)
HCV - long
HDV - superinfection - short, confection = long
HEV - short

5

HDV superinfection

HDV after HBV

6

HDV coinfection

HDV with HBV

7

HAV clinical course

Asymptomatic (usually)
Acute

8

HV clinical course

Initially like serum sickness (fever, arthralgia, rash); may progress to carcinoma.

9

HDV clinical course?

similar to HBV

10

HEV clinical course

fulminant hepatitis in pregnant women

11

HBV prognosis

Most adults have full resolution; minority have chronic infection.

12

HDV prognosis?

Superinfection --> worse prognosis

13

HCV prognosis?

majority develop stable, Chronic hep C

14

HAV liver biopsy

1) hepatocyte swelling
2) monocyte infiltration
3) councilman bodies

15

HBV liver biopsy

granular eosinophilic "ground glass" appearance.

16

HCV liver biopsy

lymphoid aggregates with focal areas of macro vesicular steatosis

17

HDV liver biopsy

similar to HBV

18

HEV liver biopsy

patchy necrosis

19

carrier state with hepatitis?

only seen with HBV and HCV

20

anti-HAV (IgG) significane

IgG antibody indicates prior HAV infection and/or prior vaccination.
*protects against reinfection.

21

HBsAg indicates...

infection

22

Anti-HBs indicates...

immunity

23

Significance of Anti-HBc

If IgM = acute/recent infection.
If IgG = prior exposure or chronic infection

24

marker of infection during window period?

1) Anti-HBe
2) IgM anti-HBc (may be sole positive marker of infection during window period).

25

What is HBeAg

Secreted by infected hepatocyte into circulation. Not part of mature HBV virion.

26

Significance of Anti-HBe

low transmissibility

27

Marker during incubation period?

HBsAg

28

Other marker of alcohol use?

ethyl glucuronide

29

Markers of prodrome, acute disease

HBsAg
IgM anti-HBc
HBeAg

30

Markers of Chronic high infectivity HBV?

HBsAg
HBeAg
IgG anti-HBc

31

Markers of Chronic low infectivity HBV?

HBsAg
Anti-HBe
Anti-HBc IgG

32

markers during recovery?

Anti-HBs
Anti-HBe
Anti-HBc IgG

33

markers of immunity?

anti-HBs

34

HIV envelope proteins?

gp120
gp41

35

gp120?

docking glycoprotein. attaches to host CD4+ cell

36

gp41?

transmembrane glycoprotein. fusion and entry

37

p17?

HIV matrix protein

38

p24?

HIV capsid protein

39

origin of gp120 and gp41?

Formed from cleavage of gp160 to form envelope glycoproteins.

40

what is gag?

codes for p24 + p17

41

what is pol?

gene that codes for reverse transcriptase + aspartate protease + integrase

42

virus binding mechanism

Binds CD4 + coreceptor (either CCR5 on macrophages in early infection or CXCR4 on T cells in late infection).

43

heterozygous CCR5 mutation?

slower course

44

homozygous CCR5 mutation?

immunity

45

ELISA characteristics

sensitive, high false positive rate and low threshold. RULE OUT.

46

Western blot characteristics for HIV

Specific, low false positive rate and high threshold. RULE IN.

47

AIDS diagnosis

1) CD4 below 200
2) HIV positive with AIDS-defining condition
30 CD4+ percentage lower than 14%

48

problem with ELISA/Western blot

Often falsely negative in first 1-2 months of HIV infection and falsely positive initially in babies born to infected mothers (anti-gp120 crosses placenta).

49

What is the window period?

Time between acute infection and recovery.

50

How can you tell AIDS stage based on surface proteins?

as patients enter the symptomatic period and as immune function declines, peoples’ ability to produce any isotype of antibody declines and thus antibodies to capsid antigen (p24) will decline (can’t class switch due to TH deficiency). Once patients develop AIDS in the final stages of the disease, they’re so deficient in T cells that they can’t undergo class switching. IgM can be made in the absence of TH cells, however, and production of IgM continues against envelope glycoproteins (gp120 and gp41) since those antigens are constantly being altered by the process of random mutation (genetic drift).

51

AIDS virus type

lentivirus (long latent period)

52

What is reverse transcriptase?

An RNA-dependent DNA polymerase because it synthesizes cDNA from an RNA template.