Viral Hepatitis

Question 1

What is viral hepatitis?

Answer 1

Inflammation of the liver caused by a virus. Symptoms include jaundice, fatigue, abdominal pain, loss of appetite. Some people don’t have symptoms.

Question 2

Hepatitis Viruses

Answer 2

Numerous and genetically distinct. However, they cause similar symptoms, infect hepatocytes, and are primarily/exclusively associated with liver disease. They often have diverse clinical features like onset, severity and chronicity

Question 3

Hepatitis A

Answer 3

AKA Infectious hepatitis, is a picornavirus. Abrupt onset, mild severity and no chronicity

Question 4

Hepatitis B

Answer 4

AKA serum hepatitis, is a hepadnavirus. Slow onset, occasionally severe, chronic

Question 5

Hepatitis C

Answer 5

AKA non A non B hepatitis, is a member of the flaviviridae family. Slow onset, usually subclinical but chronic.

Question 6

Hepatitis delta

Answer 6

AKA delta agent, is a delta virus. Abrupt onset, occasionally severe, chronic.

Question 7

Hepatitis E Virus

Answer 7

AKA enteric non A non B hepatitis, is a hepevirus. Abrupt onset, severe in pregnant women, not chronic.

Question 8

Which hepatitis viruses have a vaccine?

Answer 8

Hep A, Hep B.

Question 9

Which hepatitis viruses have a therapy?

Answer 9

Hep B (rarely cures), Hep C.

Question 10

High risk for HBV?

Answer 10

Drug users.

Question 11

HBV virology

Answer 11

Hepadnaviridae, genus orthohepadnavirus. Enveloped protein is major antigen (HBsAg)

Question 12

HBV genome

Answer 12

Partially double stranded, circular DNA genome. Smallest genome of a replication competent human virus. Replication occurs via an RNA intermediate (reverse transcription)

Question 13

Three antibodies produced in response to HBV?

Answer 13

anti-HBsAg, anti-HBeAg, anti-HBcAg

Question 14

What leads to chronic HB?

Answer 14

Anti-HBsAg

Question 15

How is hepatocellular carcinoma induced?

Answer 15

Virus theory - viral products act as oncogenes, inducing cancer from the integration of genome and disruption of cellular gene expression.

Indirect theory- chronic hepatic injury and subsquent repair processes lead to genetic changes in cells and subsequent uncontrolled growth.

Question 16

Treatment for chronic HBV?

Answer 16

Pegylated interferon alpha (antiviral cytokine), successful in 30% of patients but difficult to tolerate during 48 week therapy. Reverse transcriptase inhibitors

Question 17

HBV antivirals

Answer 17

Are RT inhibitors– lamivudine (Nucleoside analog), entecavir, tenofovir

Question 18

HBV vaccines

Answer 18

Use non-glycosylated HBsAg produced in yeast and the adjuvant alum. Safe, but requires multiple vaccinations.

Question 19

Hepatitis Delta Virus

Answer 19

Subiviral satellite virus, requires HBV to provide envelope proteins required for assembly, only affects individuals with HBV, greatly exacerbates HBV disease and increases chances of cancer.

Question 20

Fulminant hepatitis

Answer 20

Rare complication that frequently ends in death.

Question 21

HCV

Answer 21

Leading indication for liver transplants in the US, frequently from drug use and sexually transmitted.

Question 22

HCV Genome

Answer 22

Flaviviridae genus hepacivirus, single stranded positive sense RNA

Question 23

Why does HCV have a high error rate?

Answer 23

Because of an error prone RNA polymerase, so it exists as a quasispecies, allowing it to escape immune responses and be resistant to treatment.

Question 24

Outcome of HCV infection

Answer 24

Can lead to liver failure, cancer, transplant or death in 4% of people over 20-30 years.

Question 25

What enzyme spikes during infection?

Answer 25

ALT

Question 26

How to assess HCV infection

Answer 26

Serology (look for antibodies to NS3, NS5, core, 6-8 weeks after exposure)
RT-PCR
Liver Biopsy to assess injury

Question 27

How to treat HCV?

Answer 27

Curable, many drugs like interferon alpha, simepravir

Question 28

Hepatitis A virus

Answer 28

Transmission is person-person via oral fecal route, 3 week selflimited disease that is often subclinical. symptoms of acute viral hepatitis occur and detection of HAV-specific IgM antibody. Supportive therapy. Prevent with vaccine.

Question 29

Hepatitis E virus

Answer 29

Clinical presentation similar to HAV. Predominantly found in developing countries with fecal contamination of drinking water. Less widespread than HAV. Self limiting viral infection followed by recovery. Prolinged viremia or fecal shedding are unusual and chronic infection does not occur.