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What is the mechanism by which hepatitis B causes liver disease?

  • A Hepatitis B virus is understood to directly destroy infected liver cells without any involvement from the host immune system, through a cytopathic mechanism similar to that seen in poliovirus infection
  • B Hepatitis B virus infects hepatocytes; immune response (cytotoxic T cells) attempting to kill infected cells causes hepatocyte damage; chronic infection leads to cirrhosis and hepatocellular carcinoma
  • C Hepatitis B is in fact correctly classified by microbiologists as a bacterial disease rather than a viral disease, responding largely to standard antibiotic therapy in every infected patient
  • D Hepatitis B infection is understood to mainly ever cause a short-lived, self-resolving acute illness, rarely a chronic disease, with the virus being largely cleared from the liver within a few weeks

Correct answer: B. Hepatitis B virus infects hepatocytes; immune response (cytotoxic T cells) attempting to kill infected cells causes hepatocyte damage; chronic infection leads to cirrhosis and hepatocellular carcinoma

Explanation: HBV (hepadnavirus, DNA virus): infects hepatocytes → CTLs attack infected cells → inflammation → liver damage. Most adults clear it (acute hepatitis); 5% become chronic carriers → chronic hepatitis → cirrhosis → hepatocellular carcinoma (HCC). HBsAg persists in chronic infection. HBV is 100x more infectious than HIV. Vaccine available (3-dose schedule).

Concept context

Pathogens, infectious diseases, non-infectious diseases, drugs, cancer, and public health. High NEET importance.

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