Viral hepatitis etiopathology, serological and viral markers

Okay, here's a breakdown of the information from the provided text related to viral hepatitis, focusing on etiopathology, serological markers, and viral markers. I'll organize it by virus (HAV, HBV) and then by the requested categories. I'll also include some notes on general concepts where applicable.

I. General Concepts

  • Acute Viral Hepatitis: Characterized by elevated liver enzymes (ALT), often accompanied by jaundice, fatigue, and other systemic symptoms. Serum alkaline phosphatase is usually normal or mildly elevated, and a fall in serum albumin is uncommon in uncomplicated cases.
  • Immunopathology: The immune response plays a crucial role in liver damage in viral hepatitis. The host's immune system attacks infected hepatocytes, contributing to inflammation and necrosis.
  • Serological Markers: Antibodies (IgM, IgG) and viral antigens are used to diagnose, monitor, and assess the stage of infection.
  • Etiology: Viral hepatitis is caused by different viruses, each with its own mode of transmission and clinical presentation.

II. Hepatitis A Virus (HAV)

  • Etiopathology:
    • Non-enveloped, single-stranded RNA virus.
    • Infects hepatocytes, leading to inflammation and necrosis.
    • Transmitted via the fecal-oral route (contaminated food/water, close personal contact).
  • Viral Markers:
    • HAV antigen: Detection of HAV antigen in stool or serum can indicate acute infection.
    • Viral RNA: PCR assays can detect HAV RNA in stool or serum.
  • Serological Markers:
    • Anti-HAV IgM: Indicates acute infection. Appears early in the disease course and usually disappears within several months.
    • Anti-HAV IgG: Indicates past infection and immunity. Remains detectable indefinitely and confers protection against reinfection.
    • Neutralizing antibody: Correlates with anti-HAV IgG and provides protection.
  • Diagnosis: Diagnosis is made by detecting anti-HAV IgM during acute illness.

III. Hepatitis B Virus (HBV)

  • Etiopathology:
    • DNA virus with a complex structure.
    • Infects hepatocytes, leading to inflammation, necrosis, and potentially chronic infection.
    • Transmitted through blood, semen, or other body fluids (sexual contact, sharing needles, mother-to-child transmission).
  • Viral Markers:
    • HBV DNA: Detectable in serum or liver tissue. Used to assess viral load and monitor treatment response.
    • HBsAg (Hepatitis B surface antigen): Indicates active infection. Present in serum during acute and chronic infection.
    • HBcAg (Hepatitis B core antigen): Found in the nucleus of infected hepatocytes.
    • HBeAg (Hepatitis B e-antigen): Indicates high viral replication and infectivity.
  • Serological Markers:
    • Anti-HBs (Anti-Hepatitis B surface antibody): Indicates immunity (either from vaccination or past infection).
    • Anti-HBc IgM: Indicates recent or acute infection.
    • Anti-HBc IgG: Indicates past or chronic infection.
    • Anti-HBe: Indicates low viral replication and often appears as HBeAg declines.

Key points regarding HBV serology:

  • HBsAg positive, Anti-HBc IgM positive: Acute HBV infection.
  • HBsAg positive, Anti-HBc IgG positive, Anti-HBe positive: Chronic HBV infection with low replication.
  • Anti-HBs positive: Immunity.

IV. Other Considerations from the Text

  • Autoimmune Hepatitis: The text mentions autoimmune hepatitis, which can mimic viral hepatitis but is caused by an autoimmune response. It's characterized by autoantibodies and other immunological abnormalities.
  • Fulminant Hepatitis: Severe acute liver failure, often associated with viral hepatitis.

Disclaimer: This information is based solely on the provided text and is intended for educational purposes only. It should not be used as a substitute for professional medical advice. Diagnosis and treatment of viral hepatitis should be performed by a qualified healthcare provider.