Hepatitis B (HBV) Flashcards
Features
Similar clinical presentation to Hepatitis A but arthralgia and uriticaria more common
Transmission by blood spread, sex, perinatal spread, percutaneous
5% become chronic carriers but
95% with infant acquired HBV → carriers
15–40% of carriers → cirrhosis
LFTs and viral markers confirm diagnosis
HBV antigens of virus particle
HBsAg = surface antigens
HBcAg = inner core antigens
HBeAg = a soluble protein from pre-core & core
Antibodies develop to each of these
Time course of acute Hepatitis B infection
Serology guidelines
HBsAg = acute/persistent infection
anti-HBs = past infection & immunity
HBeAg = highly infective
HBV DNA = circulating & replicating virus
anti-HBc IgM = recent infection and earliest indicator
anti-HBc IgG = past infection
Serological patterns
HBsAg+ve + anti-HBc IgM+ve + anti-HBs−ve = acute hep B
HBsAg+ve + anti-HBc IgG+ve + anti-HBs−ve = chronic hep B
HBsAg−ve + anti-HBc IgG+ve + anti-HBs+ve = resolved hep B
Interpretation
HBsAg = diagnosis and/or carrier
- –if +ve do full viral profile
Progress is monitored 6–12 mthly with HBeAg, HBV DNA and LFTs:
- HBsAg –ve + HBV DNA + anti-HBe = resolving
- as above + anti-HBs = full recovery
- HBsAg +ve + HBV DNA = replicating & infective, refer
Chronic hepatitis B is defined as the presence of HBsAg for longer than 6 months.
Monitor LFTs every 6 mths—if abnormal refer to specialist.
Treatment
As for Hepatitis A; no specific treatment initially
Advise about avoiding transmission esp. safe sex, sharing needles
Address any drug dependence; avoid sedatives, NSAIDs, OCP
Medication for chronic Hepatitis B with abnormal LFTs:
antivirals: adefovir or entecavir until HBe Ag
- undetectable and
- replaced by anti-HBe twice at least 3 mths apart plus
pegylated interferon alpha-2a SCI once weekly for 48 wks
Prevention
Hepatitis B vaccine: 0, 1, 6 mths, or
Hepatitis A and B combined: 0, 1, 6 mths
Measure severity of any hepatic fibrosis by FibroScan® (transient elastography) imaging.
