Autoimmune hepatitis

Question 1

What are the risk factors for autoimmune hepatitis?

Answer 1

Female to male (4:1), HLA-DR3 or HLA-DR 4 (MHC II), Hashimoto’s thyroiditis, Graves disease.
Most common association in IBD ulcerative colitis.

Question 2

What are the types of autoimmune hepatitis?

Answer 2

Type 1 (80%): ANA +ve, ASMAs, decreased albumin, elevated prothrombin time.
Type 2: ALKM-1; young girls associated with other immune disease
Both types show ALT>AST

Question 3

How does azothioprine work?

Answer 3

Blocks the pathway for DNA synthesis. Common side effects include bone marrow suppression, vomiting and pancreatitis. Reduced TPMT levels lead to an increased production of cytotoxin thioguanine nucleotide (TGN) with an increased risk of AE.
Rare cases of hepatosplenic T-cell lymphoma have been reported (also with anti-TNF) and idiopathic pancreatitis.

Question 4

What is overlap syndrome?

Answer 4

Patients diagnosed with autoimmune hepatitis should have a cholangiogram to exclude biliary tree involvement (i.e. sclerosing cholangitis). This results from chronic inflammation of the bile ducts leading to fibrosis and can be secondary to recurrent stones/infection and is strongly associated with IBD.
There is an increased malignancy risk of colorectal and cholangiocarcinoma