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
•
Symptoms include mild flu-like syndrome, nausea, vomiting, jaundice
> 50% are asymptomatic
•
Lifelong risk of developing cirrhosis &/or HCC
•
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
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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
•
Serum HBV DNA and viral load
Natural History
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10% of infected individuals become chronically infected
•
Life-long risk of developing cirrhosis &/or HCC in chronic hepatitis B
Cirrhosis is not prerequisite for developing HCC
–
HBV viral genome can act as oncoprotein and intergrade into host genome
Related
Diagnostic Pathology Hepatobiliary and Pancreas
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.
