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MCIM 309 > Hepatitis > Flashcards

Flashcards in Hepatitis Deck (34):
1

hepatitis virus

Oral-fecal or parentally spread liver viruses.

2

how many?

6. hepatitis A - E + G

3

Target?

Liver

4

Classics?

Hepatits A virus (HAV)
Hepatitis B virus (HBV)

5

Non-A, non-B hepatitis (NANBH)?

Hepatitis C (HCV)
Hepatitis D (HDV) [the delta agent]
Hepatitis E (HEV)
Hepatitis G (HGV)

6

HAV structure + features

picornavirus
+ssRNA
One serotype
very small
oral-fecal

7

HAV replication

replicates in hepatocytes + Kupffer cells (liver). slowly. non-cytolytic, released by exocytosis.

8

HAV Symptoms

occur abruptly 15-50 days post-infection.
initial symptoms: fever, fatigue, nausea, loss of appetite, vomiting, abdominal pain.
Liver damage symptoms: Dark urine, Pale stool, Jaundice, Icterus. (rarely jaundice in children)

9

HAV recovery

Complete recovery in 99%. within 2-4 weeks of start of symptoms. up to 2 months. Lifelong immunity.

10

HAV diagnosis

based on symptoms
anti-HAV IgM ELISA or Radioimmunoassay.
cannot be isolated.

11

HAV prevention and control

water treatment + avoid uncooked shellfish.
prophylaxis or immune serum globulin treatment (80-90% effective)

12

HAV vaccines

Killed HAV vaccines.
all children after 1 year of age. high risk adults + travellers.
two doses.
one serotype.
(live vaccine in chine, crazy fuckers)

13

E-NANBH

hep E. E = enteric/epidemic.
similar to HAV but later symptoms and more mortality.
serious in preg women.
poor places.

14

HBV structure + features

hepadnavirus.
Small enveloped DNA virus, very stable.
small circular, partly (?) dsDNA. encodes RT, replicates thru RNA intermediate. Dane particles, filamentous particle, spherical particle

15

HBV Replication

entry into hepatocyte and uncoating of core. DNA is transcribed in the nucleus into mRNA, RT turns RNA into -DNA, then becomes +DNA. DNA filled core becomes associated with HBsAG, exocytosed.

16

HBV patho + immune response

tropism for liver.
replicates in liver, symptoms >45 days.
HBsAG presence causes cytopathology (necrosis)
inflammation and CMI: causes symptoms and also resolution.

17

HBV types of infection. why?

Chronic, acute symptomatic, asymptomatic. Depends on immune response.

18

HBV Chronic

weak CMI, echausted CD8 T cells. mild disease, when active liver cirrhosis, failure, major source of spread

19

HBV acute symptomatic

90% of infections. Strong CMI, after 45 days: nausea, fever, malaise, anorexia. later: jaundice, dark urine, pale stoolsresolution.

20

Fulmitant hepatitis

1% of acute symptomatic cases, kills you.

21

HBV diagnosis

initially: jaundice and liver enzymes
HBsAg & HBeAg in serum. anti-HBc&HBe&HBs. quantitative viral load by genomic PCR

22

HBV control + treatment.

HBV immune globulin: to recently exposed + neonates of + mothers.
Drugs: Iamivudine, entecavir,telbivudine, tenofovir, adefovir dipivoxii, famciclovir.
Vaccination: 1 serotype = yes. yeast recombinant vaccine,: HBsAg Virus like particle. 3 injections.

23

Hepatitis C virus family

Flavivirus

24

# of genotypes

6 (clades), considerable genetic and antigenic diversity.

25

HCV structure + features

enveloped +RNA
infects only humans and chimps.

26

HCV pathogenisis

-Acute infection:15-25% clear HCV no treatment
-Chronic HCV: Long term, ~70%
-Hepatic steatosis: fatty liver
-Hepatic Fibrosis: scarring of the liver, still reversible by clearing HCV
-Hepatic Cirrhosis: you
fuked now. severe fibrosis(scarring of living), irreversible
-hepatocellular carcinoma: you have cancer now. (1-5% of cirrhosis people)

27

HCV pathogenesis features

-inhibit apoptosis
-down regulates IFN-a response
-down regulate dendritic cell maturation
-major surface proteins E1&E2 drift.
CHRONIC INFECTION:
-antibody does nothing, need CMI. but CD8 T cells damage liver and cause cirrhosis.

28

HCV diagnosis

ELISA: anti-HCV antibody.
denome detection and quantitation by RT-PCR
mostly cannot be grown in culture.

29

HCV treatment

Recombinant IFN-a
ribavirin
boceprevir, telaprevir
ledipasvir
sofosbuvir
(combination.)
no vaccine.

30

Hepatits G virus

pretty much HCV, almost no symptomatic cases. detectable by RT-PCR

31

Hepatitis D virus HDV

requires HBV to replicate, often co-infection occurs. causes fulmitant hepatitis (fatal)

32

HDV structure

small -ssRNA

33

HDV diagnosis

anti-HDV antibodies; ELISA and radioummunoassay
RT-PCR for virion genome in blood
ELISA to detect delta antigen.

34

HDV treatment & control

no treatment,
avoid being infected by HBV