Typically transmitted vertically, parenterally, or sexually
Clinical Issues
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10% of infected patients become chronically infected
400 million people worldwide have chronic HBV
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Symptoms include mild flu-like syndrome, nausea, vomiting, jaundice
> 50% are asymptomatic
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Lifelong risk of developing cirrhosis &/or HCC
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Useful laboratory tests include serology for HBV viral antigens, anti-HBV antibodies, and HBV DNA viral load
Microscopic
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Acute hepatitis B
Hepatocytic swelling, predominantly lobular inflammation, spotty necrosis
Severe cases may show confluent and bridging necrosis, collapse of hepatocytic cords, hepatocytic regeneration
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Chronic hepatitis B
Portal-based inflammation with variably present ground-glass hepatocytes, “sanded nuclei” in hepatocytes, variable fibrosis
–
Stage of fibrosis indicates disease progression and is important therapeutic and prognostic indicator
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Immunohistochemistry for HBcAG and HBsAG may be useful, but not invariably positive
TERMINOLOGY
Abbreviations
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Hepatitis B virus (HBV)
Synonyms
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Australia antigen: Hepatitis B surface antigen (HBsAg)
Definitions
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Infection by HBV
Member of Hepadnaviridae family
Genome comprises partially double-stranded DNA virus
ETIOLOGY/PATHOGENESIS
Infectious Agents
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Transmitted parenterally
Vertical transmission: Mothers to newborn infants
Horizontal transmission: Between young children
Sexual contact
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Liver injury appears to be immune mediated
HBV-specific T cells play key role in pathogenesis and viral clearance
CLINICAL ISSUES
Epidemiology
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Incidence
400 million people worldwide are chronically infected with HBV
Presentation
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Acute hepatitis B
Symptoms include mild flu-like symptoms, nausea, vomiting, jaundice
< 1% develop fulminant liver failure leading to death or liver transplantation
Serum HBsAg and anti-HBc virus IgM Ab positive
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Chronic hepatitis B
Serum HBsAg positive and anti-HBc virus IgM Ab negative
Laboratory Tests
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Serology for HBV viral antigens: HBsAg, HBcAg, HBeAg
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Serology for anti-HBV antibodies: Anti-HBs, anti-HBc, anti-HBe
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Serum HBV DNA and viral load
have glassy eosinophilic cytoplasm representing proliferation of smooth ER in response to HBsAg.
) representing nuclear accumulation of HBcAg. These may be hard to detect on routine H&E staining.
into the periportal parenchyma.
