Viral Hepatitis Flashcards
What are the two variables in deciding who to treat for Hep B?
- HBV DNA level
- HBe Ag positive (E positive means high viral replicative state)
What is the most common cause of acute viral hepatitis?
Hep A
Which viral hepatitises are transmitted via oral fecal route?
Hep A and E (vowels)
How to treat a Hep B infection
- first line = nucleos(t)ide analog to inhibit viral DNA polymerase
- not really used any more b/c of flu-like side effects = interferon
How to treat a Hep D infection
Treat the underlying Hep B infection (nucleo(t)ide analogs to interrupt viral DNA polymerase
-if you get rid of the Hep B, the Hep D cannot survive b/c it needs Hep B’s envelope protein to infect the hepatocyte
Which Hep infections have vaccines?
HAV and HBV
How is Hep B transmitted?
mucous membranes and blood exposure
How is Hep C transmitted?
mucous membranes and blood exposure
How is Hep D transmitted?
mucous membranes and blood exposure
Marker present during incubation period of HBV
HBsAg = hep B surface antigen
-marker of acute and chronic infection (chronic if persists for > 6 mo)
Prodrome, acute disease marker of HBV
HBsAg (hep B surface antigen) and anti-HBC
-anti-HBC = Hep B core antibody IgM = marker of acute infection
Marker of high rate of viral replication in HBV
HBeAg = HepB E-antigen
Marker of seroconversion to low viral replicative state of HBV
HBeAb = HepB E surface antibody
-when pt seroconverts to HBeAb (antibody instead of the antigen) then they are much less infective
Marker of recovery from HBV
Anti-HBs and anti-HBc
Anti-HBs = HepB surface antibody
-marker of history of HBV infection or vaccination
Anti-HBc = IgG anti-HBc is a marker of cleared infection or chronic infection w/ HBV
Describe the window period in Hep B
The time btwn being surface antigen negative and surface antibody positive
Describe titer findings in a pt w/ chronic HBV
HBsAg (surface antigen) remains positive
- dont have anti-HBs (surface antibody)
- can be HbeAg positive or negative
Immune tolerant phase of HBV
- only in pts infected at birth or during early childhood
- doesnt happen in pts infected as adults
- have detectable HBV DNA in serum, but minimal inflammation or fibrosis of the liver
- immune system is not attacking the infected hepatocytes
Immune clearance phase of HBV
- immune tolerant can progress to this active immune clearance phase
- immune system starts attacking infected hepatocytes
- elevated aminotransferases, signs of chronic hepatitis
- usually HBeAg positive
Inactive carrier state of HBV
-state after immune clearance active phase where virus calms down: normal ALT and low HBV DNA levels
Reactivation phase of HBV
- uncommon, occurs after pt moves from active immune clearance –> inactive carrier state and then reactivations
- elevated ALT, high HBV DNA levels
- occurs when pt is put on immunosuppression therapy that is then withdrawn (b/c then immune system ramps up and starts attacking hepatocytes
Three indications for treating an HBV pt
(1) ALT > 2x UL (upper limit of normal)
(2) High HBV DNA levels
(3) Pts w/ decompensated cirrhosis
What is the post-exposure prophylaxis regimen for HBV?
- HBIG and HBV vaccine
- HBIG = Hep immunoglobulin that confers immunity against HBV
-also give HBIG + HBV vaccine to children born w/ infected mother (HBsAg + mother)
What is the mechanism of liver injury in HBV?
CD8+ T cells cause apoptosis of HBV infected hepatocytes
-so not due to the virus itself, but due to the immune system’s response to the virus
Compare the rate of infection after exposure to HBV and HCV?
Much higher risk of developing chronic liver disease once exposed to HCV
- only 2-5% of adults exposed to HBV => chronic liver disease (higher as you look at younger populations)
- while 50-90% of ppl infected w/ HCV progress to chronic liver disease
What are the two treatment options for HBV?
- interferon: directly affects the virus and improves immune system against the virus. but flu-like side effects
- nucleos(t)ide analogs to inhibit viral DNA synthesis
Compare course of HCC in pts w/ HBV and HCV
- pts w/ HBV can develop HCC w/ or w/o cirrhosis
- only pts w/ HCV who have cirrhosis have chance of developing HCC
Differentiate Hep D Co-infection and superinfection
Co-infection = have both hep D and hep B active infections, get infected w/ both simultaneously (better prognosis)
Superinfection = get infected w/ hep D on top of chronic HBV (worse prognosis)
What key serum measurement differentiates co-infection and super infection?
Look for IgM for Hep B core antigen (acute immune response marker to Hep B)
- if (-) IgM anti-HBc = superinfection (meaning HBV infxn is chronic)
- if (+) IgM anti-HBc = coinfection (was previously HBsAg-)
How do you treat Hep D?
Treat Hep B and then Hep D will go away
-Hep D needs the Hep B envelope protein to replicate
Which hepatitis virus is a DNA virus?
Hep B
How to distinguish a chronic from an acute HDV infection?
- acute infection will have HDV IgM (marker of acute inflammation)
- Chronic infection will have HDV IgG
Which Hep virus is known for being found in shellfish?
Hep A
-can say alive in an oyster for 5 days (ew)
Which two hepatitis viruses are self-limited?
Hep A and E- meaning they’ll run their course and resolve (most of the time) w/o intervention
Exceptions
- Hep A => fulminant hepatitis in some pts
- Hep E very dangerous in pregnant women
What is a clinical finding common to all hepatitis viruses?
Jaundice!
-in hep A starts around week 4
What is the treatment for HEV?
Mostly supportive care (all that is needed b/c is usually self-limited)
^same for Hep A
-while rare cases (esp. pregnant women) may require liver transplant
Which hepatitis has 6 specific genotypes?
HCV
-genotypes important for determining treatment
Which genotype of HCV is the most common in the US?
Genotypes 1a/1b
What is the marker of a chronic HCV infection?
- presence of HCV RNA for > 6 months
- serum ALT levels usually fluctuate
Ribavirin
-nucleoside inhibitor used (in conjunction w/ interferon) to treat Hep C
What is the leading cause of liver transplant in the US?
HCV
Common outcomes of chronic HCV
- cirrhosis
- in pts w/ cirrhosis => HCC
What are three markers present in an acute HBV infection?
- HBsAg (surface antigen)
- HBcAb IgM (acute antibody against core protein)
- HBV DNA (detectable via PCR)
