Exam #5: Viral Hepatitis Flashcards Preview

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Flashcards in Exam #5: Viral Hepatitis Deck (44):
1

What is hepatitis?

Disease marked by inflammation of the liver.

2

What are the non-viral causes of hepatits i.e. what is your differential diagnosis when a patient has abnormal LFTs?

- Alcoholism
- Drug abuse
- Drug overdose/ toxin (Tylenol especially)
- Metabolic disorder

Viral Hepatitis

3

What is acute viral hepatitis? What are the symptoms?

Viral hepatitis <6 months of symptoms:
- Jaundice--increased bilirubin leading to yellowing of the skin & sclera
- Liver inflammation-- RUQ abdominal pain
- Dark urine
- Acholic stool--clay-colored stool caused by a reduction in bile production

4

What is the prodrome prior to the onset of hepatits?

Headache
myalgia
arthralgia
fatigue
nausea
vomiting
pharyngitis
mild fever

5

What is bilirubin? Why is hyperbilirubinemia seen in viral hepatitis?

Bilirubin is the end-product in the recycling of heme from dying RBCs. It is normally excreted as bile, which requires conjugation in the liver. Viral hepatitis interferes with liver function & prevents normal conjugation of bilirubin; thus, higher than normal levels are seen in the blood & urine.

6

What are the bilirubin levels that are seen in hepatitis? How do they correlate with the symptoms?

Bilirubin levels of 5-20 mg/dL are common in viral hepatitis.
- 3 mg/dL= jaundice
- Higher= bilirubin in urine (diagnostic of liver disease)

7

What liver enzymes are elevated in hepatitis?

AST (aspartate aminotransferase)
ALT (alanine aminotransferase)

8

What is the definition of chronic viral hepatitis? What are the potential complications of chronic hepatitis?

Hepatitis that does not resolve in 6 months

Predisposition to primary hepatocellular carcinoma & cirrhosis*
*Usually it takes 15-40 years to see these symptoms

9

What causes tissue damage in chronic hepatitis? Why are primary heptacellular carcinoma & cirrhosis associated with chronic hepatitis?

Continued replication of hepatitis virus & subsequent immune response leads to an inflammatory response & tissue destruction

Note that the the liver regenerates; long-term/ continued regeneration is what predisposes to the development of primary hepatocellular carcinoma

10

What is fulminant viral hepatitis? What are the symptoms of fulminant hepatitis? What are some of the complications of fulminant hepatits?

This is the most severe form of viral hepatitis that affects BRAIN function. There is a massive hepatic necrosis in fulminant hepatitis, which leads to hyperammonemia.
- Encephalopathy-->confusion, disorientation, coma.
- Ascites & edema are indicative of liver failure
- Life threatening complications

*Liver transplant can be lifesaving

11

What virus family is Hepatitis A a part of? How is it transmitted? Does it lead to chronic infection?

Picornovirus
Fecal-Oral
No

12

What virus family is Hepatitis B a part of? How is it transmitted? Does it lead to chronic infection?

Hepadnavirus
Body fluids
Yes

13

What virus family is Hepatitis C a part of? How is it transmitted? Does it lead to chronic infection?

Flavivirus
Body fluids
Yes

14

What virus family is Hepatitis D a part of? How is it transmitted? Does it lead to chronic infection?

Deltavirus
Body fluids
Yes

*Helper-dependent
*Direct damage

* Remember that HDV is helper-Dependent & causes Direct Damage

15

What virus family is Hepatitis E a part of? How is it transmitted? Does it lead to chronic infection?

Hepevirus
Fecal-Oral
No

16

List the characteristics of Hepatitis A.

Picornovirus family
+ssRNA

17

What are the clinical manifestations of Hepatitis A infection?

Incubation period is 28 days
Presents as acute hepatitis
Does NOT cause chronic
Rarely causes fulminant hepatitis

18

How is Hepatitis A diagnosed?

- anti-HAV IgM antibodies are indicative of ACUTE infection
-anti-HAV IgG antibodies provide protection against re-infection and are indicative of vaccine or prior infection

19

How is Hepatitis A prevented?

Vaccination:
- inactivated whole HAV vaccine
- IM (2x doses)
- Given to children (12-23 months)
- High risk groups

Post-exposure prophylaxis
- Vaccine can be used as post-exposure prophylaxis
- anti-HAV IgG can also be given as post-exposure prophylaxis

20

List the characteristics of Hepatitis B. Describe the proteins associated with HBV.

- Hepadnavirus family
- Partially dsDNA genome (some ss)
- Reverse transcription is part of its lifecycle
(most commonly passed via sexual contact)

Note that there are three relevant viral proteins (clinically)
1) HBsAg= surface antigen
2) HBcAg= core antigen (between viral genome and HBsAg) --NOT soluble i.e. NOT in serum
3) HBeAg= core protein that IS SOLUBLE

21

What are the morphological characteristics of Hepatitis B? Which are infectious? What are the antigens associated with each?

- Tubules & Spheres= noninfectious products of HBsAg (surface antigen)
- Dane particles= infectious, virion coated in tubules & spheres

Note that the presence of tubules & spheres in the bloodstream is indicative of ACTIVE HBV infection.

22

Serologically, how do you tell the difference between acute & chronic hepatitis?

HBsAg= marker of active infection (either acute or chronic)
HBsAb (antibody)= is present in vaccinated or previous infected patients, but NOT active infection
HBcAb- IgM= acute infection
HBcAb- IgG= chronic infection (or prior infection)
HBeAg+HBcAb- IgG= chronic replicative

The presence of ONLY antibodies in serum is indicative or RESOLVED infection.

23

What is HBsAg a serologic marker of?

Both acute & chronic Infection

24

How many HBV infections progress to chronic infection in the following populations: a) neonates, b) 5 year-olds, c) general population?

a) 90% in neonates
b) 15% in 5 year-old
c) 5-10% in general population

*Note that chronic infection increases the risk for liver cirrhosis & primary heptocellular carcinoma

25

What are the symptoms of Hepatitis B infection?

Less severe infection than acute HAV

26

How is HBV infection treated?

Acute= none
Chronic=
- Lamivudine= reverse transcriptase inhibitor
- Famcylovir/Adefovir= nucleoside inhibitor, which can be done with or without Interferon-alpha

27

What is the HBV vaccine?

Recombinant HBV surface protein (HBsAg)
- IM injection
- Recommended for all infants with the first dose given soon after delivery

28

Describe the post-exposure phrophylaxis protocol for HBV.

HBV vaccine & Hepatitis B Immune globin (HBIG) are used for post-exposure prophylaxis.
- Premature infants with unknown maternal HBV status & HBV positive receive BOTH
- Unvaccinated exposed receive (e.g. healthcare worker) receive just vaccine

29

List the characteristics of HCV.

Flavivirus family
Enveloped
+ssRNA

*Highly associated with IV drug use
* Note that there are six genotypes (most common in the US is Type 1)

30

How is HCV diagnosed?

Screening Test with ELISA
Confirmatory Test with Western Blot

Note that this protocol is similar to what is done with HIV

31

What are the serologic features of HCV?

- ALT & Anti-HCV elevations seen ~2months post-expsoure
- HCV RNA seen early (acute infection)

32

What are the disease outcomes of HCV?

HCV has a higher propensity to develop into chronic hepatitis than HAV (none) & HBV
- 15% of patients develop acute hepatitis that is more mild than HAV or HBV (self-resolving)
- 15% progress to rapid cirrhosis
- 70% develop chronic/ persistent HCV infection

33

How is HCV treated?

- Treatment is for CHRONIC infection ONLY
- Treatment regimen differs depending on the exact genotype, but currently, antiviral protocols contain sofosbuvir for every genoptye
- Sofosbuvir is an RNA dependent RNA polymease inhibitor

*Note that while this new drug has an improved efficacy, it comes at a heavy cost (~1,000 dollars a pill)

34

How is HCV prevented?

No vaccine
Reduce risk behavior
Screen blood supply

35

List the characteristics of HDV.

Deltavirus
Circular ssRNA
Encodes delta proteins

"Helper-dependent" (needs "co" or prior infection by HBV)

36

What is unique about the lifecycle of HDV?

Replication requires HBV proteins; thus, it only infects cells that have been previously or concurrently infected with Hepatitis B virus.

37

What is most likely to cause fulminant hepatits?

Concurrent infection with HBV & HDV

38

What is the only hepatitis virus that damage hepatocytes directly?

HDV

39

How is HDV diagnsed?

ELISA to detect:
- anti-HDV antibodies
- delta proteins

40

How is HDV treated?

No specific antiviral treatments; thus, supportive therapy ONLY

41

How is HDV prevented?

Because HDV absolutely requires HBV infection, prevention includes HBV prevention (HBV vaccination)

42

List the characteristics of HEV.

Hepeviridae family
+ssRNA
non-enveloped

43

How is HEV treated?

Supportive therapy

44

How is HEV prevented?

HEV is spread through the fecal-oral route; thus, prevention entails preventative sanitation measures

There is NO vaccine for HEV

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