Viral hepatitis (A, B, C, D, E) - causes, symptoms, diagnosis, treatment & pathology

Summary

This video explains the various types of viral hepatitis and their impact on the liver. It covers the mechanisms of liver inflammation, immune responses, and the role of specific liver enzymes, antibodies, and markers in diagnosis. The script highlights key differences between Hepatitis A, E, C, B, and D, detailing transmission methods, symptoms, and the progression from acute to chronic stages. It also emphasizes the importance of immunization and proper testing, particularly for Hepatitis B and C, as well as the risks associated with chronic infections like liver cirrhosis and cancer.

Takeaways

• 😀 Hepatitis refers to liver inflammation, often caused by viral infections targeting liver cells.
• 😀 Immune cells, especially CD8-positive T-cells, recognize abnormal proteins from infected liver cells, leading to cytotoxic killing and apoptosis of hepatocytes.
• 😀 Hepatocytes undergoing apoptosis are known as Councilman bodies, which can be seen in histology, often in the portal tracts and lobules of the liver.
• 😀 Common symptoms of hepatitis include fever, malaise, nausea, hepatomegaly (enlarged liver), and increased blood transaminases (ALT and AST).
• 😀 Elevated ALT and AST are markers of liver damage, with ALT typically being higher than AST in viral hepatitis.
• 😀 Atypical lymphocytosis (large lymphocytes) is a common finding in viral hepatitis due to immune cell activation.
• 😀 Jaundice in hepatitis results from a mix of conjugated and unconjugated bilirubin in the blood, with darker urine due to increased conjugated bilirubin excretion.
• 😀 If hepatitis lasts more than six months, it transitions from acute to chronic hepatitis, potentially progressing to cirrhosis.
• 😀 Hepatitis A and E are transmitted via the fecal-oral route and usually do not cause chronic infection, but HEV can be particularly dangerous for pregnant women.
• 😀 Hepatitis C and B are transmitted through blood, with HBV being linked to liver cancer, and both having chronic forms that require specific diagnostic tests like PCR or antigen tests.

Q & A

What is the primary cause of hepatitis?

Hepatitis is most commonly caused by viral infections that target liver cells, leading to inflammation and liver damage.

What is the role of CD8-positive T-cells in hepatitis?

CD8-positive T-cells recognize abnormal proteins presented by infected liver cells and initiate cytotoxic killing, leading to hepatocyte apoptosis and inflammation in the liver.

What are Councilman bodies, and where are they found?

Councilman bodies are apoptotic hepatocytes, which are often seen in histology during viral hepatitis. They are typically found in the portal tracts and lobules of the liver.

What are some common symptoms of viral hepatitis?

Common symptoms include fever, malaise, nausea, hepatomegaly (enlarged liver), jaundice, and increased liver enzymes such as ALT and AST.

Why do transaminase levels increase in viral hepatitis?

Transaminase levels (ALT and AST) increase in viral hepatitis because liver cells (hepatocytes) are damaged and leak these enzymes into the bloodstream.

What is the significance of atypical lymphocytosis in viral hepatitis?

Atypical lymphocytosis, characterized by large lymphocytes, is a common finding in viral hepatitis. These large lymphocytes result from stimulation by the hepatitis virus antigens.

How does bilirubin metabolism change in hepatitis, leading to jaundice?

In hepatitis, hepatocytes are damaged, leading to a loss of the ability to conjugate bilirubin. This results in both conjugated and unconjugated bilirubin accumulating in the blood, causing jaundice.

What is the difference between Hepatitis A and Hepatitis E?

Both Hepatitis A and E are transmitted via the fecal-oral route and are usually acute infections with no chronic state. The major difference is that Hepatitis E can be very severe in pregnant women, potentially causing acute liver failure, whereas Hepatitis A is typically self-limited and has a vaccine.

What is the diagnostic method for Hepatitis C, and why is PCR important?

For Hepatitis C, an HCV RNA test using PCR is the gold standard for diagnosis. It detects viral RNA early in infection, providing accurate insight into viral load and whether the patient is recovering or has chronic infection.

What role does immunization play in the prevention of hepatitis B?

Immunization for Hepatitis B introduces the IgG antibody for the Hepatitis B surface antigen, effectively preventing infection without going through the steps of acute infection and immune response.

How does Hepatitis D virus affect patients with Hepatitis B?

Hepatitis D virus requires the presence of Hepatitis B to infect the host. If the two infections occur simultaneously, it is co-infection, but if Hepatitis D infects after Hepatitis B, it is superinfection, which is considered more severe.