Autoimmune hepatitis

Question 1

def

Answer 1

chronic hepatitis of unknown cause
characterised by autoimmune features
-hyperglobulinaemia
-presence of circulating autoantibodies

Question 2

aetiology

Answer 2

combination of environmental & genetic factors

1 a genetically predisposed individual exposed to an environmental agent (virus/drugs) may lead to hepatocyte expression of HLA antigens
2 HLA antigens become the target of a T-cell-mediated autoimmune attack
3 chronic inflammatory changes are similar to those seen in chronic viral hepatitis:
-lymphoid infiltration of portal tracts
-hepatocyte necrosis
which leads to fibrosis & cirrhosis

features of PBC or PSC can be present

Question 3

what are the two types of autoimmune hepatitis

Answer 3

type 1 (classic)
-ANA
-anti-smooth muscle antibodies (ASMA)
-anti-actin antibodies (AAA)
-anti-soluble liver antigen
type 2 (anti-SLA)
-antibodies to liver/kidney microsomes (ALKM-1)
-antibodies to liver cytosol antigen (ALC-1)

Question 4

epi

Answer 4

type 1 in all age groups (commonly young women)

type 2 is a disease of girls & young women

Question 5

history

Answer 5

may be asymptomatic

insidious onset
-weight loss
-jaundice
-amenorrhoea
-epistaxis
acute hepatitis (25%)
-fever
-nausea, vomiting, diarrhoea
-jaundice
-RUQ pain
-serum sickness (arthalgia, polyarthritis, maculopapular rash)
-personal/family history of other autoimmune disease

Question 6

what is a maculopapular rash

Answer 6

flat, red area on the skin which is covered in bumps

Question 7

examination

Answer 7

• stigmata of chronic liver disease (spider naevi)
• ascites, oedema, encephalopathy are late features
• cushingoid features (rounded face, thin skin, hirsuitism)

Question 8

investigations - overview

Answer 8

1 bloods
2 liver biopsy
3 other investigations
4 imaging
5 ERCP

Question 9

investigations - bloods

Answer 9

1 LFTs
-very high AST, ALT, GGT
-high alkphos, bilirubin
-low albumin in severe disease
2 clotting
-prolonged PT time in severe disease
3 FBC
-low Hb
-low platelets & WCC if hypersplenism from portal HTN present

4 hypergammaglobulinaemia typical with presence of ANA, ASMA - type 1 (classic)

Question 10

investigations - liver bipsu

Answer 10

establish diagnosis

Question 11

investigations - other investigatiosn

Answer 11

for exclusion
1 viral serology (hep B & C)
2 caeruloplasmin & urinary copper (wilson’s disease)
3 ferritin & transferrin (haemochromatosis)

Question 12

investigations - imagine

Answer 12

USS/CT/MRI

-to visualise structural lesions

Question 13

investigations - ERCP

Answer 13

to exclude PSC