Hep B/D Flashcards
HBV
Type of virus
Survivability days ex-vivo
Transmission
Potential for chronic infection
Curable
Type of virus
- DNA
Survivability days ex-vivo
- 7 days
Transmission
- percutaneous, sexual, perinatal
Potential for chronic infection
- Yes
Curable
- No
What is the natural progression of acute to chronic HBV?
- Acute HBV
- Chronic HBV
- Cirrhosis OR HCC (hepatocellular carcinoma)
HBV can skip fibrosis and cirrhosis to go to HCC
Symptoms of HBV infection
- Fever, fatigue, loss of appetite, N/V, abdominal pain
- Dark urine, clay-colored BM, jaundice
- Joint pain
Risks for chronic HBV infection? (2)
Symptoms
- Age (risk drops as you grow older)
- HIV+
Asymptomatic or non-specific symptoms
What is the main reason of the difficulty in achieving HBV clearance during chronic HBV
- cccDNA (covalently closed circular)
- HBV transcriptase enzyme makes RNA intermediate, this enzyme lacks proof-reading, so high risk of mutations
HbsAg
Timeline for acute/chronic infection
When is it detectable
Acute
- pos for up to 6 months
Chronic
- pos for 6+ months
Detectable in ~ 4 weeks
Interpretation of Anti-HBs
- Recovery of HBV infection
- Immunity from HBV infection (vaccine)
What is the HBcAg and anti-HBC value mean?
Infected liver cells make this Hep B core protein that stays in the liver
If anti-HBC positive, indicates previous or ongoing HBV infection
- need to look at IgM to see if it is acute
What does the IgM & IgG anti-HBc value mean
Onset?
IgM: indicates ACUTE HBV infection
- does not persist
- or if severe chronic exacerbation
IgG:
- persists during CHRONIC HBV infection
Both appear 1-2 weeks after HBsAg
What is the HBeAg value correlated to and used for?
Correlates with higher HBV DNA levels and higher risk for HBV transmission.
- ONLY USEFUL FOR TREATMENT MONITORING
What does Anti-Hbe value indicate
Indicates transition from active HBV infection to inactive carrier status.
Present in individual with low HBV replication levels & in HBeAg negative disease.
What is the HBV DNA value useful for?
Useful for prognosis and monitoring.
- High VL increases risk of cirrhosis and HCC development.
Risk factors for progression to cirrhosis: (2)
- Higher HBV DNA levels
- HIV-positive individuals with chronic HBV infection
may progress to cirrhosis, ESLD, and/or HCC faster + have higher mortality rates
How do we prevent hep B (2)
Energix-Hb
Recombivax-HB
Dose at 0, 1 and 6 month
When is the ideal time to get Hep B vaccination?
Vaccine dose?
What is it in ontario?
24 hours after birth give Hep B vaccine + IgG injection (if available)
- Give IgG only if mother is HBsAg+ and HBeAg+
- repeat Hep B vaccine at 1 and 6 months
Ontario: Grade 7
When do we use prophylaxis in mother to prevent HBV transmission to child?
What drug
TDF is recommended in 3rd trimester if HBV DNA level is over 200,000+ units/mL. Use until 4 weeks postpartum
What additional info do you need before treating chronic Hep B? (5)
- CBC, Hepatic function panel, prothrombin time
- Check for co-infection: HDV, HIV, HCV
- Family history of liver cancer
- Pregnancy plans?
- Co-morbidities
T/F Antiviral treatment does not eliminate risk of HCC in hep B
True
What criteria should we look at for treatment of HBV according to WHO (3)
- HBV DNA level
- Serum ALT
- Liver disease severity (i.e cirrhosis)
How do the NRTIs work in hep B
Interfere with HBV DNA polymerase and prevent DNA replication
What are the 4 treatment options for Hep B?
TDF/TAF
High potency
High genetic barrier to resistance
Entecavir
- High potency
- High genetic barrier to resistance
- Minimal HBV resistance
- Not used as HIV drug
PegIFN
- AVOID in patients with decompensated cirrhosis (less safe)
- not well tolerated
What kind of cure can we achieve with Hep B treatment
Immunological cure =
- HBsAg loss
- sustained HBV DNA suppression
Virological cure = NOT achieved (defined by eradication of virus – including cccDNA form)
What are the goals of treatment for Hep B?
Long-term goals?
- Prevent liver cirrhosis
- Prevent carcinoma
- Prevent death
- Improve liver histology
Long-term oral HBV treatment:
- Suppress HBV DNA
- Normalize ALT
- Prevent fibrosis progression
- Prevent fibrosis regression (even in cirhhosis)
- Prevent & even reversing hepatic decompensation
- Reducing (but not eliminating) risk of HCC
- Reducing risk of liver transplant
Which drug is the best at losing HBsAg antigen
PegIFN
