Viral Hepatitis Flashcards
A 52y/o male presented to the hospital August 12th with increasing nausea, vomiting, jaundice over 2-3 weeks duration. The patient has no significant comorbid illnesses. He does drink alcohol occasionally but denies illicit drug use. He takes no medications. On June 14, he had unprotected sex with a female prostitute and was treated for gonorrhea.
What is the syndrome?
Hepatitis (most likely Hep B but coud also be C but not as common)
What are the signs and symptoms of hepatitis?
Fatigue, nausea, vomiting, malaise, abdominal pain (localizing to the RUQ), nausea, loss of appetite, change in stool (chalky/clay-colored), chills, headache, myalgias.
Signs include jaundice and icterus
Which hepatitis virus can be sexually transmitted? What are the characteristics of this virus?
Hepatitis B (virion is also known as Dane particle)
Hep B is Hepadnah virus. Actually partially ds DNA virus, has reverse transcriptase and gets its envelope from the ER.
Describe the replication cycle of Hep B
Viral entry >> uncoating >> viral genome transported to nucleus and kept as CCC dna >> dna can then be transcribed using reverse transcriptase and kept as progeny DNA genome or following transcription, translated in the cytoplasm
**know that cccDNA persists in the host indefinitely and the folks in whom cccDNA persists have chronic disease**
Hep B has a few antigens important for Dx and its function. Which antigens exist inside the virus’ core? Which ones are on the virus’ surface?
Core antigen is in the center of the virus. There’s also the e antigen (indicator of transmissibility – that’s the one that correlates well to viral dna load according to B/B)
Outer coat of the virus has Hep B surface antigen (made of small, medium, large proteins)
T/F: Hepatitis B infection is directly responsible for damage to the host liver
Falsehood. Damage to liver is immune mediated damage to infected hepatocytes
How is Hep B transmitted?
Hep B is transmitted thru blood, sexual contact and from mother to child (in the absence of prophylaxis)
There are 2 categories of tests you can conduct for Hep B. What are they?
What are the proteins you’ll be testing for each group?
Markers of Hep B virus: HBV dna (viral load), HB e Ag, HB s Ag
Antibodies to the antigens: anti Hb core (IgM/IgG to tell acute vs chronic), anti Hb e; anti Hb s
Explain the graph below, depicting Hep B testing
Total anti-HBc represents IgM and IgG
Window period (around 28 weeks): point at which HB surface antibody isn’t high enough yet and surface antigen in no longer detectable so the only detectable entity is total core antigen
Almost everyone with acute hepatitis will have +ve surface antigen
**so at infection or right after infection: the first thing to pop up is Hep B surface antigen, then antibodies to Hep B core antigen, then anti-Hb surface antibodies pop up later on**
What test results would you expect to determine if pt has resolved acute Hep B infection?
Which serological marker will be +ve during the window period?
If pt is seen after resolution of infection, the only things that’ll be +ve are IgG to HB core ag, and surface antigen (surface antigen itself will be negative)
The IgM to hepatitis core antibody will be positive during the window period
23 year old Asian female presents to establish her primary care. She was born in China and is a college student. She does not drink, does not use illicit drugs and is not sexually active. She has no complaints and a normal physical exam. She was referred based on +ve Hep surface antigen test but all other lab values including liver enzymes and function tests are normal. She has a very high HBV dna load.
Since she has no other risk factors for infection, where could she have acquired it?
She most likely acquired HBV at birth and has chronic infection.
**remember that infants born to mothers with untreated HBV can get chronic infection and also she was born in an endemic area - #China**
What does the Hep B graph of a pt with chronic infection look like (i.e. which antigens/antibodies will be high, which ones are low/absent etc)?
Notice how she never makes the antibodies to the Hep B surface antigen because she’s chronically infected, and that HB e antigen is prolonged (note also that she has a very high viral load)
How do the Hep B markers differ in a vaccinated person vs a resolved infection?
The difference between a vaccinated person and someone who’s resolved an acute infection is the core antibody. Every marker will be the same except the core antibody will be negative in the vaccinated person
Describe the natural history of Hep infection (as in, what happens after people get to chronic infection)
**see image below**
(note that chronic infection by itself can increase risk of liver hepatocellular carcinoma without having to have cirrhosis first)
Between younger and older pts, who is more likely to develop chronic disease vs clear the infection?
Older patients will be more symptomatic but have a higher likelihood of clearing the infection because of the host immune response (remember it’s the immune response that gets us to being symptomatic so in younger folks who have a less robust immune response, they can be asymptomatic but will have a higher likelihood of developing chronic infection)
What are extra hepatic manifestations of HBV?
Polyarteritis nodosa (PAN) and other vasculitidies
Glomerulonephritis
Serum sickness (acute)
Arthralgias
Describe the replication cycle of Hep C virus
Note that the virus replicates in the cytoplasm (specifically on the endoplasmic reticulum), gets its envelope from the ER and is secreted out of hepatocytes using lipid secretory mechanisms
Describe the natural history of Hep C virus
see image below
**the thing to remember is that most people WILL infact progress to chronic disease, however most of those folks will be stable and getting treated significantly reduces chance of progression**
You need to see this one
