Week 4: Liver Pathology - Acute and Chronic Viral Hepatitis Flashcards
What are the general characteristics of Viral Hepatitis, and what are common causative agents?
Viral Hepatitis = characterised by the presence of Hepatocyte Necrosis and Inflammation, resulting from systemic viral infection
Causative Agents:
Most commonly one of the 5 hepatotropic viruses: Hepatitis A, B, C, D or E
Other Viruses: EBV (Epstein-Barr virus), HSV (Herpes Simplex Virus) and CMV (Cytomegalo virus) can also be associated
Basic Features of Hep A (HAV)
Occurs sporadically or endemically
Faecal-oral transmission
Causes Acute disease only
Basic Features of Hep B (HBV)
Occurs sporadically or endemically
Transmission: sexual, perinatal and parenteral
Chronic disease persists in 5% of adults and in up to 90% of infants
*Clinical severity is increased if co-infected with HDV
Chronic Hep B infection is associated with Hepatocellular Carcinoma (HCC) - primary malignant liver tumour
Basic Features of Hep C (HCV)
Sporadic occurrence
Transmission: Parenteral. Perinatal and sexual spread is less common
Chronic disease develops in 60-80% of individuals
Chronic Hep C infection with accompanying Liver Cirrhosis is associated with Hepatocellular Carcinoma (HCC) - primary malignant liver tumour
Basic Features of Hep D (HDV)
Sporadic or Endemic occurrence
Can also occur as a co-infection with HBV (Hep B)
Transmission: Parenteral and sexual
Chronic disease is seen in patients with cronic HBV
HDV worsens the clinical severity of HBV
Basic Features of Hep E (HEV)
Sporadic or Endemic occurrence
Transmission: Faecal-oral
Results in Acute disease only
Mortality in pregnant women is 25%
What types of syndromes can occur as a result of hepatitis?
Acute subclinical and anicteric (non-jaundice) with recovery
Acute symptomatic and icteric (jaundiced) with recovery
Fulminant hepatitis occurs in <1% cases - mortality rate exceeds 80% in patients who have not had a liver transplant
Chronic Hepatitis - asymptomatic without hepatocyte necrosis, compensated and decompensated cirrhosis
Describe the Histology of acute hepatitis
Acute Hepatitis:
Predominantly lobular inflammation, with subsequent lobular regeneration and disarray
“Ballooning” hepatocyte degeneration
Apoptotic bodies (acidophils)
Mononuclear inflammatory cells, with occasional eosinophils and neutrophils
Canalicular cholestasis
Hepatocyte dropout and necrosis which is
- Focal
- Confluent with bridging necrosis (seen in fulminant hepatitis)
- Interface
What are the major differential diagnoses to consider whilst diagnosing viral hepatitis?
Drug toxicity
Toxin exposure
Alcohol
Autoimmune Hepatitis
Wilsons Disease (AR disorder involving copper accumulation in tissues - neurological and liver symptoms)
Idiopathic
Other infectious Hepatitis’ - e.g. bacterial, fungal, parasitic
What are the major differential diagnoses to consider whilst diagnosing viral hepatitis?
Drug toxicity
Toxin exposure
Alcohol
Autoimmune Hepatitis
Wilsons Disease (AR disorder involving copper accumulation in tissues - neurological and liver symptoms)
Idiopathic
Other infectious Hepatitis’ - e.g. bacterial, fungal, parasitic
Describe the basic features and most common causes of bacterial infectious hepatic lesions
Generally, pyogenic abscesses are secondary infections resulting from seeding from other sites - usually the GI or biliary tracts. Often polymicrobial.
Hepatic abscess formation/infection from local spread - predisposing conditions:
- diabetes
- intra-abdominal malignancies
- cholangitis (inflammation of bile duct)
- idiopathic IBD
- Appendicitis
- Diverticulosis (affects bowel wall)
- Tumours, cysts and infarctions may also become secondarily infected, leading to abscess formation
Hepatic involvement may also occur due o systemic bacteriaemia (sepsis)
Granulomatous inflammation can be seen in TB or atypical mycobacterial infarction
Describe the basic features of bacterial infectious hepatic lesions
Generally, pyogenic abscesses are secondary infections resulting from seeding from other sites - usually the GI or biliary tracts. Often polymicrobial.
Hepatic abscess formation/infection from local spread - predisposing conditions:
- diabetes
- intra-abdominal malignancies
- cholangitis (inflammation of bile duct)
- idiopathic IBD
- Appendicitis
- Diverticulosis (affects bowel wall)
- Tumours, cysts and infarctions may also become secondarily infected, leading to abscess formation
Hepatic involvement may also occur due o systemic bacteriaemia (sepsis)
Granulomatous inflammation can be seen in TB or atypical mycobacterial infarction
Describe the most common causes of parasitic infectious hepatic lesions
Hepatic parasitic infections can occur due to:
- Hydatid disease (caused by echinococcosis - dog tape worm)
- Schistosomiasis (infection caused by genus schistosoma - types of trematodes)
- Amoebic Liver Abscess (caused by amoebiasis)
- Malaria (mosquitto-bourne infectious disease caused by protozoans)
Describe the most common causes of parasitic infectious hepatic lesions
Hepatic parasitic infections can occur due to:
- Hydatid disease (caused by echinococcosis - dog tape worm)
- Schistosomiasis (infection caused by genus schistosoma - types of trematodes)
- Amoebic Liver Abscess (caused by amoebiasis)
- Malaria (mosquitto-bourne infectious disease caused by protozoans)
What are the most common aetiologies of Chronic Hepatitis?
Viral: Hep B, C and D are most common
Autoimmune
Drug Induced
Alcohol
Metabolic: alpha-1 anti-trypsin deficiency, Wilson’s Disease, Haemochromotosis, NASH
Chronic Biliary DIsorders: Primary and Secondary Biliary Cirrhosis, and Primary Sclerosing Cholangitis
Describe the Histology of Chronic Hepatitis
Chronic Hepatitis Histology:
Predominantly Portal Tract Inflammation
Lobular Acidophil Bodies
Mononuclear inflammatory cells
Occasional Plasma Cells
Portal-based lymphoid aggregates and lymphoid follicle formation
Progressive fibrosis with eventual cirrhosis
Interface Hepatitis (loss of demarcation between portal area and hepatic parenchyma)
Bile ductular proliferation
Describe the Grading and Staging of Chronic Hepatitis
CH is graded in terms of: Portal/Periportal activity, Lobular activity, and Fibrosis
Portal/Periportal Activity: None/minimal = 0 Portal inflammation only = 1 Mild interface hepatitis = 2 Moderate interface hepatitis = 3 Severe interface hepatitis = 4
Lobular activity:
None = 0
Inflammatory cells but no hepatocellular death = 1
Focal cell death = 2
Severe focal death, +/- confluent necrosis, without bridging = 3
Damage includes bridging necrosis = 4
Fibrosis:
None = 0
Enlarged, fibrotic portal tracts = 1
Periportal or portal-to-portal septa, but intact architecture = 2
Fibrosis with architectural distortion, but no obvious cirrhosis - 3
Probable or definite cirrhosis = 4
Describe the Grading and Staging of Chronic Hepatitis
CH is graded in terms of: Portal/Periportal activity, Lobular activity, and Fibrosis
Portal/Periportal Activity: None/minimal = 0 Portal inflammation only = 1 Mild interface hepatitis = 2 Moderate interface hepatitis = 3 Severe interface hepatitis = 4
Lobular activity:
None = 0
Inflammatory cells but no hepatocellular death = 1
Focal cell death = 2
Severe focal death, +/- confluent necrosis, without bridging = 3
Damage includes bridging necrosis = 4
Fibrosis:
None = 0
Enlarged, fibrotic portal tracts = 1
Periportal or portal-to-portal septa, but intact architecture = 2
Fibrosis with architectural distortion, but no obvious cirrhosis - 3
Probable or definite cirrhosis = 4
Describe the characteristics of Chronic Hep C
Chronic HCV is the most common viral cause of hepatitis
Characterised by:
- Steatosis (fat in the liver)
- Prominent lymphoid aggregates, or even fully developed lymphoid follicles with germinal centres
- Inflammatory bile duct damage
Describe the characteristics of Chronic Hep C
Chronic HCV is the most common viral cause of hepatitis
Characterised by:
- Steatosis (fat in the liver)
- Prominent lymphoid aggregates, or even fully developed lymphoid follicles with germinal centres
- Inflammatory bile duct damage
Describe the important pathological/histological features of Autoimmune Hepatitis
Typical picture:
- Chronic hepatitis with prominent interface hepatitis
- Plasma cells are more prominent than in other forms of chronic hepatitis
- Significant steatosis, cholestasis/bile duct damage is NOT SEEN
Describe the important pathological/histological features of Autoimmune Hepatitis
Typical picture:
- Chronic hepatitis with prominent interface hepatitis
- Plasma cells are more prominent than in other forms of chronic hepatitis
- Significant steatosis, cholestasis/bile duct damage is NOT SEEN
Describe the basic features associated with drug/toxin induced liver injury:
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