Patterns of Liver Injury 2 - Chronic Hepatitis Flashcards
What is chronic hepatitis?
persistence of liver injury with raised serum aminotransferase levels for more than 6 months
What causes chronic hepatitis?
chronic HBV and HCV, autoimmune hepatitis, drugs
Do all patients with chronic elevation of liver enzymes have chronic hepatitis?
no - may be non alcoholic fatty liver disease - need biopsy to confirm diagnosis
What are the symptoms of chronic hepatitis?
may have no symptoms - or may have few symptoms like fatigue and loss of appetite
What are the histological features of chronic hepatitis?
portal tract is heavily infiltrated by lymphocytes and show interface hepatitis (where lymphocytes spill over into periportal tissue)
What determines the grade of chronic hepatitis?
degree of interface hepatitis
Is interface hepatitis specific for chronic hepatitis?
no - but it is a hallmark feature
What is the pattern of fibrosis in chronic hepatitis?
bands that radiate outward from the portal tract
What determines the stage of chronic hepatitis?
the degree of fibrosis - stage 1 to stage 4 (stage 4 is cirrhosis)
What happens in the progression of fibrosis in chronic hepatitis?
Starts of as enlarged portal tract, then strands of collagen extend towards central vein, then get bridging of fibres and eventual get fibrous tissue contraction, loss of normal anatomical structure and cirrhosis
What is non alcoholic fatty liver disease?
steatosis with or without steatohepatitis and fibrosis
What are the associations of NAFLD?
obesity, metabolic syndrome, diabetes
What is steatosis?
an accumulation of abnormal amount of lipid in hepatocytes
What are the two types of steatosis?
macrovesicular (common) and micro vesicular (rare)
What causes macro vesicular steatosis?
increased triglyceride synthesis - caused either by obesity or alcohol
What is steatohepatitis?
steatosis accompanied by inflammation and hepatocyte injury - at risk of fibrosis
What is the hallmark feature of steatohepatitis?
hepatocellular ballooning
How do you determine whether the liver has steatohepatitis or alcoholic hepatitis?
Clinical diagnosis - histological features are identical
What is the pattern of fibrosis in non alcoholic steatohepatitis (NASH)?
pericellular fibrosis- ‘chicken wire fibrosis’
What causes the inflammation in NASH?
hepatocellular free fatty acids develop into lipotoxic metabolites because they can no longer be converted to triglycerides as the pathway is overloaded (due to diet and insulin resistance)
