Hepatitis Virus Flashcards
Virology for Hepatitis A?
- Picornavirus
- Fecal Oral Transmission
- One Serotype
- IgG protective against reinfection
Px of Hep A infection?
Most people recover completely - no chronic infection
What determines the severity of Syx of Hep A infection?
Severity is directly correlated with age of patient
Clinical findings of Hep A?
- Jaundice
- Fatigue, Fever
- Anorexia, Nausea, Vomiting
- Dark Urine, Pale Feces
Lab tests for Hep A?
- Enzyme Immunoassay (EIA) for Anti-HepA IgM (Acute)
- EIA for Anti-Hep A IgG (chronic)
- Ultrasound biopsy if concerned about fulminant hepatic failure
What is the general trend of Hepatitis A time course of infection?
- Viremia
- Virus in feces
- Elevated transaminases (Syx and Jaundice occur w/i this timeframe)
Hepatitis A prevention?
- Hep A vaccine (Twinrix: HAV and HBV)
- Serum Ig prophylaxis
- Handwashing, sanitation
Tx for Hep A?
Bed rest, hydration
Hep E virology?
- Small, naked ssRNA (hepevirus)
- Fecal oral
- “The Hep A of China”
- One serotype
Hep E disease highlights?
- Very similar acute disease of Hep A
- Mortality rate is 10X > Hep A
Stages of Hep E?
- Prodrome - Anorexia, Nausea, Vomiting
- Icteric Phase - Jaundice, Dark Urine, Pale Feces
Labs used to detect Hep E?
- Serology not widely available - send to CDC
- High serum ALT, AST, bilirubin w/ negative Ab for other Hep viruses
Tx and prevention for Hep E?
- Prevention: Boil water, IgG prophylaxis is NOT available, HEV239 vaccine
- Tx - Light activity, supportive Tx
Difference b/w Hep A and E?
- Hep A is picornavirus
- Hep E has a higher mortality
Virology of Hepatitis B?
- Human-restricted
- Hepadnavirus
- Messy virus
- Enveloped
- Only one serotype
- Carries reverse transcriptase
- Leaves behind integrated copies of viral DNA
Transmission of Hep B?
Injection of blood, less efficiently by sexual or birth contact
Difference b/w HepB and Heps A&E?
- HepB is enveloped and has a DNA genome
Describe the timecourse of HBV infection
- Surface antigen (HBsAg) appears early
- Surface Ab (HBsAb) rises as HBsAg falls
- Core antibody (HBcAb) arises a little later IgM for acute, IgG for chronic
- E antigen detectable when virus is most transmissible
What are the four stages of Hep B/immune interaction?
- Immune tolerance - Virus replicates w/o Syx; Hep B DNA and antigens in serum
- Immunogenic Syx - ALT increases, Hep B DNA declines; Either 3-4 wk OR chronic and leads to cirrhosis
- Clearing the virus - viral replication shuts down, HBeAb detected, HepB DNA not detected, ALT declines, HBsAg remains
- Viruse cleared - No viral Ag, permanent HBsAb IgG
Typical outcome of HBV in adults?
- 90% Resolution
- 1% fulminant hepatitis
- 9% HBsAg+ > 6months: Patients can resolve, be aSyx carriers, Chronic persistent hepatitis or Chronic active hepatitis leading to cirrhosis HCC or extrahepatic disease
Describe the pathogenesis and complications of chronic Hep B infection
- T-cell response is cytotoxic and causes cirrhosis
- Accumulation of Hep AgAb leads to kidney damage/arthritis
- Virus genome integration, expression of viral transcriptional transactivators leading to cancer
Exam findings for Hep B?
- Acute phase: Icteric - Fatigue, Fever, Jaundice, Aversion to food/cigs, anorexia, nausea, vomiting
- Chronic: Spider angiomas, palmar erythema, hepatomegaly
Hep B laboratory tests?
- HepB antigens (HBsAg, HBeAg)
- Anti-HepB Ab (surface, core, e antigen)
- ALT, AST, bilirubin
When is liver biopsy performed for Hep B? Findings?
Chronic/active infection; Inflammation around portal tracts, ground glass cytopathology, positive staining for Hep B antigens
What is the best method for HBV prevention?
- Vaccination (HBsAg)
- Ab prophylaxis (HBsAb)
- Condoms
Tx strategy for Hep B?
- Supportive care for acute hep
- Active chronic infection - 1 year of polymerase inhibitors PLUS 4 months of pegylated alpha-interferon
What are the issues with treatment of HBV?
Pegylated alpha interferon has significant toxicity
Virology of Hep D?
- VIRIOID
- Cannot replicate by itself
- Requires Hep B
- Spread by blood and sex
- Produces Delta antigen - cytotoxic
Describe the relationship b/w Hep B and Hep D
- Coinfection: Same clearance rate as Hep B alone
- Superinfection: Chronic Hep B then acquires hep D results in fulminant disease
Hep D Dx?
EIA for anti-delta Abs
Prevention and Tx for Hep D?
- Hep B vaccincation or Ig
- If HepB + halt risky behavior
- Tx: year of pegylated alpha-interferon - Px grim
Hep C virology?
- Flavivirus
- Enveloped
- RNA genome
- Transmitted efficiently by blood
- Higher potential for chronic infection than Hep B
- NO vaccine
Outcome of Hep C infection?
- 85% progress to persistent infection and chronic hepatitis resulting in liver failure, cirrhosis, or HCC
What are some red flags for Hep C infection?
- Baby boomer who got a tatoo way back
- Travel to Egypt - blood fluke eradication gone wrong
Signs of HCV infection on exam?
- Milder Syx than HBV - Arthralgia, myalgia, pruritus
- Liver failure - jaundice, vasculitis, autoimmunity, palmar erythema, icteric sclera
Hep C lab Dx?
- LFTs
- EIA followed by a RIBA
- RTPCR for viral RNA
What is a RIBA and why is it used?
Recombinant Immunoblot assay for HCV used as a follow up for HCV because HCV serology gives many false positives;
Vendor provides HCV antigens, patient’s serum is used and then fluorescent Abs provided by the vendor are used to ID HCV Abs in the patient’s serum
Hep C Prevention and Tx
- Prevention: No vaccine
- Acute infection: Short course of pegIFN reduces rate of chronic infection
- Chronic infection: Proceed w/ drug Tx of Ribavirin (chain terminator), PegIFN, IF SEROTYPE 1 - HCV protease inhbitor
What is the goal of Tx for Hep C and why is Tx still beneficial if Tx “failed”?
- Goal: Sustained viral response: Remission
- Failed Tx may still reduce risk of HCC
What Hep C serotypes have bette response to Tx?
- Serotypes 2 and 3 >50% SVR rate with 6 months PegInterferon + ribavirin
- Serotypes 1 and 4 require 1-2 yrs Tx and still have lower recovery rates
What Hep patients can potentially utilize liver transplant?
Hep C and possible HepB/D
What should be performed before transplant occurs?
Hit patient hard with pegIFN to clear body of as much virus as possible
