Copy of 1. ACUTE AND CHRONIC HEPATITIS (1)

Learning Objectives

• Define acute hepatitis and identify its causes.

• Understand the pathophysiology of acute viral hepatitis (AVH).

• Recognize clinical presentations of patients with AVH.

• Outline diagnosis, outcomes, prevention, and treatments of AVH.

• Define chronic hepatitis and discuss its causes.

• Explore the clinical presentation, diagnosis, and prognosis of chronic hepatitis.

• Summarize prevention and treatment strategies for chronic hepatitis.

Hepatic Structures

The Hepatic Lobule

• Anatomic unit of the liver.

• Components include central vein and portal triad.

The Hepatic Acinus

• Functional unit, divided into 3 zones based on oxygen gradient and metabolic function.

Overview of Hepatitis

• Broad term for conditions with liver necroinflammation.

• Classified by duration: acute and chronic hepatitis.

Acute Hepatitis

Definition

• Acute necroinflammation associated with elevated serum aminotransferases.

Causes

• Viral Infection: Most common cause.

• Non-infectious: Alcohol, drugs (dose-dependent and non-dose-dependent).

• Immunologic Diseases: e.g., autoimmune hepatitis.

Acute Viral Hepatitis

• Virally-mediated acute necroinflammation.

• Caused by hepatotropic (liver-specific) and non-hepatotropic viruses.

Common Hepatotropic Viruses

• HAV, HBV, HCV, HDV, HEV

  • Transmission routes vary; some are vaccine-preventable.

  • Chronic infection potential differs by virus.

Pathogenesis of Acute Viral Hepatitis

• Injury primarily from immune responses rather than direct viral effects.

Clinical Presentation

• Varies from asymptomatic to acute liver failure.

• Phases include prodromal (influenza-like symptoms), icteric (jaundice), and post-icteric (recovery).

Diagnosis

• Based on serum aminotransferases, bilirubin, and urinalysis.

• Elevated levels indicate necrosis; imaging and biopsy rarely needed.

Prognosis and Prevention

• Varies by virus; HAV and HEV are usually self-limited.

• Vaccination for HAV and HBV recommended for high-risk populations.

Chronic Hepatitis

Definition

• Necroinflammation lasting 6 months or more.

Causes

• Viral: HBV, HCV, others.

• Drug-induced: e.g., isoniazid.

• Alcoholic and Autoimmune causes.

Clinical Presentation

• Often asymptomatic; can lead to cirrhosis and HCC.

• Mild symptoms such as fatigue and nausea.

Diagnosis

• Liver biopsy is gold standard; tests for viral markers and liver function.

Prognosis

• Varies by etiology; HBV can progress rapidly to cirrhosis.

Prevention and Treatment

• Focus on vaccination against hepatitis B and safe medical practices.

• Treatment involves managing causes, reducing inflammation, and preventing fibrosis.

Overview of Hepatitis

• Definition: Broad term for conditions involving liver necroinflammation. Classified into two durations: acute and chronic hepatitis.

• Acute Hepatitis:

  • Characterized by acute necroinflammation and elevated serum aminotransferases.

  • Causes:

    • Viral Infection: Most common cause (e.g., HAV, HBV, HCV, HDV, HEV).

    • Non-infectious: Alcohol, drugs (both dose-dependent and non-dose-dependent).

    • Immunologic Diseases: e.g., autoimmune hepatitis.

  • Clinical Presentation: Ranges from asymptomatic to acute liver failure, with phases including prodromal, icteric, and post-icteric.

  • Diagnosis: Based on serum aminotransferases, bilirubin, and urinalysis; imaging and biopsy are rarely needed.

  • Prognosis: Varies by virus; HAV and HEV typically self-limited.

  • Prevention: Vaccination for HAV and HBV recommended for high-risk populations.

• Chronic Hepatitis:

  • Defined as necroinflammation lasting 6 months or more.

  • Causes: HBV, HCV, drug-induced (e.g., isoniazid), alcoholic, autoimmune.

  • Clinical Presentation: Often asymptomatic; may progress to cirrhosis and hepatocellular carcinoma (HCC).

  • Diagnosis: Liver biopsy is the gold standard; tests for viral markers and liver function are crucial.

  • Prognosis: Dependent on etiology; HBV can rapidly progress to cirrhosis.

  • Prevention and Treatment: Focus on vaccination against hepatitis B, safe medical practices, and managing underlying causes to reduce inflammation and fibrosis.