Autoimmune Hepatitis Flashcards
What is thought to be the cause of autoimmune hepatitis?
T-cell mediated destruction of hepatocytes due to recent viral infection triggering TC to recognise hepatocytes as foreign cells and therefore mount immune response
NOTE:
-BC and plasma cells are also involved
Eg hypergammaglobulinaemia and auto-antibodies
Which form of autoantibody is associated with younger patients?
LKM:
-liver kidney microsomal antibodies
What are the 2 types of AI hepatitis?
Who is generally affected by each type and how would they present?
Type 1:
-adults
Eg women in late 40s/50s presenting with fatigue and signs of liver disease post-menopause
Type 2:
- teenagers + early twenties
- more acute hepatitis= high transaminases and jaundice
- lethargy
- anorexia
- non-specific abdo pain
- spider naevi + splenomegaly in the absence of cirrhosis
Which autoantibodies are associated with each type of AI hepatitis?
Type 1:
- Anti-nuclear antibodies (ANA)
- Anti-smooth muscle antibodies (ASM)
- Anti-soluble liver antigen (anti-SLA)
Type 2:
- Anti-liver kidney microsomes-1 (anti-LKM1)
- anti-liver cytosol antigen type 1 (anti-LC1)
What are the histological changes associated with AI hepatitis?
Portal inflammation with plasma cells
Interface hepatitis with rosetting of periportal hepatocytes
Lobular inflammation
What are the 3 main presentations someone with autoimmune hepatitis might present with?
Acute hepatitis-> jaundice
Chronic hepatitis
Cirrhosis
How is AI hepatitis diagnosed?
NOT one singular test:
- LFTs -> any elevated liver enzymes could be AI hepatitis so will need other tests to confirm or deny
- raised bilirubin
- high ferritin= due to being acute phase response protein (need to rule out haemochromatosis)
- histological tests via biopsy= biopsy required for diagnosis
- Autoantibodies
What is the importance of detecting and treating AIH early?
Early treatment can prevent progression to liver cirrhosis meaning patient has excellent prognosis
What signs might a patient present with that would indicate their AIH had progressed to liver cirrhosis?
Splenomegaly
Ascites
Variceal bleeding
Encephalopathy= due to liver not clearing ammonia via the urea cycle
How is AIH managed?
High dose steroid eg Prednisolone
-used to induce remission (marked by normal LFTs) but should not be used longer term due to associated risks of high dose steroids
Steroid sparing agent used as MAINTENANCE drug Eg Azathioprine (immunosuppressant)
Liver transplant for late stage AIH
What are the 3 possible points in AIH natural history which would be indicators for liver transplant?
Decompensated cirrhosis
Hepatocellular carcinoma
Fulminant hepatitis
What histological changes occur in AIH?
Florid interface hepatitis
- inflammation spilling over the portal tract
- rich in plasma cells