Hepatitis B

Pathophysiology

The complete virion or Dane particle is 42 nm in diameter. It consists of:

  • A core particle made up of the nucleocapsid protein, the viral genome, and the polymerase protein

Replication cycle-

  • Attachment of the virion to the hepatocyte membrane.
  • The receptor for HBV (and hepatitis D virus) has been identified as a bile salt transporter, sodium taurocholate cotransporting polypeptide (NTCP), which binds to the pre-S1 region of the HBV envelope.
  • The virion is uncoated in the hepatocyte cytoplasm and the viral genome enters the hepatocyte nucleus.
  • Inside the hepatocyte nucleus, synthesis of the plus strand HBV DNA is completed and the viral genome is converted into a covalently closed circular DNA (ccc DNA).

Mechanism of Hepatocyte injury-

  • Immune-mediated.
  • Direct hepatocytic effect of HBV when viral load is high.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s