4.43

Question 1

Hepatitis -

Answer 1

a clinical syndrome characterized by

inflammation of the liver

Question 2

hepatocyte cell death releases

—, which causes jaundice

Answer 2

bilirubin

Question 3

bilirubin is a biproduct of

Answer 3

heme
metabolism in the liver (where heme
is detoxified)

Question 4

Hepatitis viruses have a strong tropism for the liver

and preferentially replicate in the —

Answer 4

hepatocyte

Question 5

—% of liver cells are hepatocytes

Answer 5

85

Question 6

Therefore these viruses primarily cause

Answer 6

liver

disease

Question 7

Infectious hepatitis (A and E) (2)

Answer 7

Hit and run

Fecal-oral

Question 8

Serum hepatitis (B, C, and D) (2)

Answer 8

Hide and infiltrate

Blood & sexual fluids

Question 9

virus: hep A
nucleic acid composition:
virus family:

Answer 9

linear + ssRNA

picornaviridae

Question 10

Hepatitis A

characteristics (4)

Answer 10

• infectious hepatitis
• HAV
– icosahedral, naked capsid virus
– positive strand linear RNA

Question 11

Hepatitis A

• spread by

Answer 11

fecal-oral contamination of food, drink, or

shellfish

Question 12

HAV shed into bile ducts and into intestine and

Answer 12

passes out of the body in the feces

Question 13

HAV directly kills —

Answer 13

hepatocytes

Question 14

HAV

•clinical manifestations (2)

Answer 14

–usually mild intestinal infection

–occasionally viremia occurs, leading to liver infection (jaundice)

Question 15

HAV

tx (2)

Answer 15

– killed HAV vaccine (now recommended for all in US, esp. for
military, frequent travelers, staff of care facilities)
– Post-exposure immune globulin

Question 16

In highly endemic regions, almost all children become infected in first few years of life (2)

Answer 16

• most remain asymptomatic

- adults from nonendemic regions who become infected are more likely to display symptoms

Question 17

virus: hep B
nucleic acid composition:
virus famiy:

Answer 17

nicked circular, mostly dsDNA

hepadnaviridae

Question 18

Hepatitis B

characteristics (2)

Answer 18

Enveloped

Smallest viral genome: 3200 nucleotides

Question 19

Hepatitis B

3 distinct viral particles

Answer 19

–22 nm particle
–Variable tubular/filamentous particle (22 nm diameter)
–42 nm Dane particle (infective form of virus)

Question 20

Embedded in lipid bilayer
(envelope)
— is the main component

Answer 20

HBsAg-S

Question 21

— is a processed form of the core, HBcAg.

Answer 21

HBeAg

Question 22

HBeAg is mostly secreted from infected cells and found

in —. Useful marker for —.

Answer 22

bloodstream

HBV infection

Question 23

–22 nm particle
— is the
main component

Answer 23

HBsAg-S

Question 24

Variable tubular/filamentous particle (22 nm diameter)

filaments are enriched for —

Answer 24

HBsAg-L

Question 25

Both types of 22 nm particles are empty
envelopes. Most are —.
Up to — particles per mL!

Answer 25

spherical

10^13

Question 26

Partially double
stranded DNA
genome; only
— nt in size

Answer 26

3200

Question 27

RT occurs during

Answer 27

viral

assembly, unlike retroviruses

Question 28

Reverse transcription is by

Answer 28

viral reverse transcriptase

Question 29

Priming of reverse transcription by TP (terminal protein domain) of viral
polymerase by

Answer 29

adding first nucleotide to a tyrosine residue of TP

Question 30

Cell-mediated immune response determines course of

Answer 30

HBV infection

Question 31

Cytotoxic T
lymphocytes kill
infected —

Answer 31

hepatocytes

Question 32

HBV does not directly kill hepatocytes

Answer 32

Cytotoxic T lymphocytes directed against MHC
class I proteins bound to viral antigens on
hepatocyte surface

Question 33

Killing also occurs by

Answer 33

cytokine release that

promotes inflammation and tissue damage

Question 34

Outcomes of acute HBV infection
–% infants infected with HBV become
chronically infected

Answer 34

90

immature cell-mediated immune response

Question 35

Hepatocellular carcinoma - why? (2)

Answer 35

increased cell division due to regeneration - increases
chances of mutations
peroxides and free radicals from CTL killing

Question 36

•treatment, prevention, and control (4)

Answer 36

–vaccination recommended for all infants in USA
–HBsAg particles produced in yeast
–passive immunotherapy within 7 days of exposure
–reverse transcriptase inhibitors (originally anti-HIV drugs)

Question 37

virus: hep D
nucleic acid composition:
virus family:

Answer 37

Circular - ssRNA

deltaviridae

Question 38

• hepatitis D virus (HDV)

– Depends on — virus to replicate

Answer 38

HBV

Question 39

Chronic HBV infection
exacerbated by infection
with

Answer 39

hepatitis delta virus

Question 40

virus: hep C
nucleic acid composition:
virus family:

Answer 40

linear + ssRNA

flaviviridae

Question 41

Hepatitis C

characteristics (2)

Answer 41

• enveloped
• In addition to HCV transmission through blood and sexual
fluid, HCV also spreads from mother to fetus, by fecal-oral
route, and through organ transplants

Question 42

HCV also does not directly kill hepatocytes

Answer 42

Cytotoxic T lymphocytes directed against MHC class I proteins bound to viral antigens on
hepatocyte surface

Question 43

HCV

Killing also occurs by

Answer 43

cytokine release that promotes inflammation and tissue damage

Question 44

Mixed cryoglobulinemia

Answer 44

immune complex disease of
kidney and other sites
- disease outside of liver
Inflammation and blockage of
small and medium blood vessels
caused by cryoglobulin deposition

Question 45

virus: hep E
nucleic acid composition:
virus family:

Answer 45

linear + ssRNA

caliciviridae

Question 46

hep E
Not budding; released
as a

Answer 46

naked capsid

virus

Question 47

Hepatitis E

• spread in

Answer 47

contaminated food and drink (like HAV)

Question 48

Hepatitis E

transmission

Answer 48

• human-to human transmission and animal-to-human

transmission (common source = pigs) (zoonosis).

Question 49

HEV shed into

HEV directly kills —

Answer 49

bile ducts and into intestine and passes out of the body in the feces
hepatocytes