Autoimmune hepatitis Flashcards
give the typical presentation for autoimmune hepatitis?
young patient
acute liver failure not due to viral or drugs
define autoimmune hepatitis?
Autoimmune hepatitis (AIH) is a chronic inflammatory disease of the liver of unknown aetiology. It is characterised by the presence of circulating auto-antibodies with a high serum globulin concentration, inflammatory changes on liver histology, and a favourable response to immunosuppressive treatment
what are the risk factors for autoimmune hepatitis?
female gender
genetic predisposition
immune dysregulation
measles virus
outline the aetiology of autoimmune hepatitis?
In a genetically predisposed individual, an environmental agent (e.g. viruses or drugs) may lead to hepatocyte expression of HLA antigens, which then become the focus of a principally T-cell-mediated autoimmune attack
Raised titre of anti-nuclear antibodies(ANA), anti-smooth muscle antibodies (ASMA) and anti-liver/kidney microsomes (anti-LKM) are NOT thought to directly injure the liver
The chronic inflammatory changes are similar to those seen in chronic viral hepatitis with lymphoid infiltration of the portal tracts and hepatocyte necrosis-> leads to fibrosis and, eventually, cirrhosis
what are the 2 major forms of autoimmune hepatitis?
Type 1 (Classic)
- ANA
- ASMA
- Anti-actin antibodies
- (AAA)
- Anti-soluble liver antigen (anti-SLA)
Type 2
- Antibodies to liver/kidney microsomes (ALKM-1)
- Antibodies to liver cytosol antigen (ALC-1)
summarise the epidemiology of autoimmune hepatitis?
Type 1: occurs in ALL age groups (but mainly young women)
Type 2: generally occurs in girls and young women
what are the presenting symptoms of autoimmune hepatitis?
May be asymptomaticand discovered incidentally through abnormal LFT
Insidiously present with:
- Malaise
- Fatigue
- Anorexia
- Weight loss
- Nausea
- Jaundice
- Amenorrhoea
- Epistaxis
Acute hepatitis (25%)presents with:
- Fever
- Anorexia
- Jaundice
- Nausea/Vomiting/Diarrhoea
- RUQ pain
- Some may present with serum sickness (e.g. arthralgia, polyarthritis, maculopapular rash)
what history is important to take for autoimmune hepatitis?
check for personal or family history of other autoimmune diseases
full history is important to rule out other causes of hepatitis-> viral, alcoholic
what are the signs of autoimmune hepatitis on physical examination?
Stigmata of chronic liver disease(e.g. spider naevi, hepatomegaly, jaundice)
Ascites, oedema and hepatic encephalopathy are late features
Cushingoid features(rounded face, acne, hirsuitism, cutaneous striae) may be present even before the administration of steroids
what are the appropriate investigations for autoimmune hepatitis?
LFTs:
High: AST, ALT, GGT, ALP and Bilirubin
Low: albumin (in severe disease)
Clotting:
High PT (in severe disease)
FBC:
Low Hb, platelets and WCC (if hypersplenism from portal hypertension)
TO CONSIDER: Hypergammaglobulinaemia is typical with:
Presence of ANA, ASMA and Anti-LKM antibodies
what investigations should we consider for autoimmune hepatitis?
To rule out other causes of liver disease:
- Viral serology (hep B/C)
- Urinary copper/caeruloplasmin (Wilson’s disease)
- Ferritin and transferrin saturation (haemochromatosis)
- a-1antitrypsin (for deficiency)
- Anti-mitochondrial antibodies (PBC)
US, CT or MRI of liver and abdomen
- Visualise structural lesions
ERCP
- To rule out PSC
what are the complications of autoimmune hepatitis?
Fulminant hepatic failure – severe impairment of hepatic functions in the absence of pre-existing liver disease
Cirrhosis
Complications of portal hypertension – varices, ascites
Hepatocellular carcinoma
Side-effects of corticosteroid treatment
outline the prognosis of autoimmune hepatitis?
Older patients more likely to have cirrhosis at presentation but may be more likely to respond to treatment
80% achieve remission by 3 years
35-50% remain in remission when immunosuppression withdrawn
50% require lifelong maintenance
5 year survival rate: 85% if treated, 50% if untreated
5 year survival rate after transplant > 80%
what are the indications for management for autoimmune hepatitis?
Aminotransferases > 10xthe upper limit of normal
Symptomatic
Histology: significant interface hepatitis, bridging necrosis or multiacinar necrosis
what is the management for autoimmune hepatitis?
Immunosuppression:
- Steroids, e.g. prednisolone, followed by maintenance treatment with gradual reduction in dose
- Maintenance phase: azathioprin or 6-mercaptopurine (steroid-sparing agents) with frequent LFT and FBC monitoring
- Note: test for TPMT1 activity before starting azathioprine or 6-MP
- Treatment is often long term
Monitor
- Ultrasound and alpha-fetoprotein level every 6-12 months in patients with cirrhosis – to detect hepatocellular carcinoma
- Repeat liver biopsies to check disease progression
- Hep A and B vaccinations
Liver transplant-> If patient refractory/intolerant to immunosuppression therapy/end-stage of disease
