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
Define persistent low-level viremia?
What is undetectable HBV DNA
Plateau in HBV DNA decline after 96 weeks of treatment
- HBV DNA is <2000 units/mL but still not undetectable
undetectable HBV DNA = <10 units/mL
How does lamivudine resistance shape Hep B treatment?
Need to double Entecavir dosing
What do we monitor for patients receiving Hep B treatment?
During first year
- ALT q3/4months then q6months
- HBV DNA q3/4 months then q6-12 thereafter
HBeAg/anti-Hbe in HBeAg+ patients
HBsAg q12 months (if HBV DNA is consistently undetectable)
What is the duration of treatment for Hep B?
When is it a discussion rather than indefinite treatment?
Still being studied
Indefinite
- Cirrhosis
- HBeAg negative
A discussion to consider
- HBeAg POSITIVE
Lamuvidine (3TC) dosing in Hep B and HIV
Hep B = 100mg
HIV = 300mg
If have both, use 300mg
PegIFN
Duration
Monitoring
Contraindication
ADR
Duration: 48 weeks qweek SC
Monitoring:
- CBC q1-3 months,
- TSH q3months,
- clinical monitoring (autoimmune, ischemic, neuropsychiatric, infectious complications)
Contraindication
- Decompensated cirrhosis
ADR
- flu-like symptoms, fatigue, cytopenia, modd
What is the treatment for HIV/HBV co-infect
2 NRTI
- TDF/TAF
- FTC/3TC
INSTI + PI
NNRTI
What is HEP D
- Only occurs if you have Hep B (incomplete virus that requires the help of HBV to replicate)
- Smallest virus to infect humans
- Most SEVERE form of chronic viral hepatitis (associated with rapid progression to cirrhosis & liver failure, higher risk of HCC)
- Not curable
What is the treatment for Hep D?
What if they have have elevated HBV DNA too?
PegIFN-alpha
- Tx success = undetectable HDV RNA 24 weeks post-treatment completion
Bulevirtide
- First in-class entry inhibitor
- Not yet in USA or Canada
What if they have have elevated HBV DNA too?
- Use TDF/TAF or entecavir with it
