Autoimmune Liver Disease Flashcards
(44 cards)
Give examples of autoimmune liver disease.
Primary biliary cholangitis (PBC)
Primary sclerosing cholangitis (PSC)
Autoimmune hepatitis
What is PBC?
Interlobular bile ducts are damaged by chronic autoimmune granulomatous inflammation causing cholestasis which may lead to fibrosis, cirrhosis and portal HTN.
Cause of PBC.
Unknown environmental triggers + genetic predisposition leading to loss of immune tolerance to self-mitochondrial proteins.
What is the hallmark antibody for PBC?
Antimitochondrial antibodies (AMA)
Prevalence of PBC.
<4/100000
Female 9:1 Male
Risk factors of PBC.
+ve FH
Many UTIs
Smoking
Past pregnancy
Other autoimmune conditions
Use of nail polish and hair dye.
Typical age of presentation of PBC.
50 years old
Clinical features of PBC.
Usually asymptomatic and diagnosed after incidental finding of increased ALP.
Lethargy, sleepiness and pruritus may precede jaundice by years.
Jaundice
Skin pigmentation
Xanthelasma
Xanthoma
Hepatosplenomegaly
Complications of PBC.
Cirrhotic complications
Osteoporosis
Malabsorption of fat-soluble vitamins (A, D, E, K) due to the cholestasis
Osteomalacia
Coagulopathy
HCC
Blood test findings in PBC.
Increased ALP and gamma GT
Mildly increased or normal AST and ALT
Increase in bilirubin and decrease in albumin.
Increase in prothrombin time.
AMA +ve
Other autoantibodies might be present.
Immunoglobulins are increased and especially IgM
TSH and cholesterol might be increased or normal
Why might you do an ultrasound in PBC?
To exclude extrahepatic cholestasis.
Biopsy findings in PBC.
This is usually not needed unless drug-induced cholestasis or hepatic sarcoidosis needs to be excluded.
Granulomas around the bile ducts and cirrhosis can be present.
Treatment of PBC.
Treat the symptoms;
Pruritus - try colestyramine 4-8g/24h PO, naltrexone or rifampicin
Diarrhoea - codeine phosphate 30mg/8h PO
Osteoporosis management
Give fat-soluble vitamin prophylaxis of A, D, E and K.
Consider high-dose ursodeoxycholic acid which can improve survival and delay transplantation.
Monitoring of PBC.
Regular LFTs
Ultraound and AFP twice yearly if cirrhotic
Indications for liver transplantation in PBC.
End-stage disease or intractable pruritus.
Prognosis of PBC.
Highly variable
Mayo survival model is a validated predictor of survival that combines age, bilirubin, albumin, PT time, oedema and need for diuretics.
What is primary sclerosing cholangitis? (PSC)
Progressive cholestasis with bile duct inflammation and strictures.
Clinical features of PSC.
Jaundice
Chronic right upper quadrant pain
Pruritus
Fatigue
Hepatomegaly
If it is advanced you might see ascending cholangitis, cirrhosis and hepatic failure.
Associations of PSC.
Male sex
HLA-A1, B8, DR3
Autoimmune hepatitis
80% of northern europena patients also have IBD (usually UC)
Cancer risks in PSC.
Bileduct cancer
Gallbladder cancer
Liver cancer
Colon cancer
How are cancers in PSC monitored?
Yearly colonscopy and ultrasound
Consider doing a cholecystectomy for gallblader polyps.
Test findings in PSC.
Increased ALP and bilirubin
Hypergammaglobulinaemia
Increased IgM
AMA -ve
Can be ANA, SMA or ANCA positive.
Gold standard investigation for diagnosis of PSC
MRCP
Will show bile duct lesions and strictures
Findings on ERCP or MRCP in PSC.
Abnormal duct anatomy and damage.
It can show strictures and a characteristc beaded appearance.
MRCP might show intrahepatic ducts with multifocal strictures.
These strictures might be hard to distinguish from cholangiocarcinoma.
