Conditions Affecting LFTs Flashcards
What are the LFTs?
- Bilirubin (BR)
- Alkaline phosphatase (AP)
- Alanine transaminase (ALT)
- Aspartate transaminase (AST)
- Gamma GT (GGT)
- Albumin
Which LFTs rise in hepatitis?
ALT and AST
What is cholestasis?
Obstructive jaundice, liver obstruction
What are the 3 types of cholestasis?
1) Pre-hepatic
2) Hepatic
3) Post-hepatic
Which LFTs rise in cholestasis?
AP and GGT
What are the 3 types of biliary disorders (affect bile ducts)?
1) Large duct obstruction (extra hepatic biliary disorder)
2) Primary sclerosing cholangitis (large and/or small biliary disorder)
3) Primary biliary cholangitis (small interlobular biliary disorder)
What are common causes of abnormal liver enzymes/cirrhosis?
- Alcohol
- Medications
- NAFLD incl. NASH
- Space occupying lesion
- Chronic Hep B/C
- Haemochromatosis
What do you have to do for every patient with abnormal LFTs?
Investigate
What are rarer causes of abnormal liver enzymes/cirrhosis?
- Autoimmune hepatitis
- Primary biliary cholangitis
- Primary sclerosing cholangitis
- Alpha 1 antitrypsin deficiency
- Wilson’s disease
- Coeliac disease
- Sero-negative arthritis
What investigations do you do for someone with abnormal LFTs?
- FBC
- INR
- U&E
- Lipids
- Imaging - US and dopplers
- Immunology
- Virology (HBsAg, Hep C AB)
- Chemistry - ferritin, copper/caeruloplasmin
What immunology tests do you do for someone with abnormal LFTs?
- Autoantibodies - ANAs, smooth muscle antibodies, anti-mitochondrial antibodies, anti-endomyseal antibodies
- Immunoglobulins
What is normal ALT?
50 IU/L
What is haemochromatosis?
Autosomal recessive disorder that leads to iron overload (HFE gene)
When do you want to diagnose haemochromatosis before?
Before ferritin is 1000 and before organ failure
What are clinical features of haemochromatosis?
- Cirrhosis
- Skin pigmentation
- Diabetes
- Cardiomyopathy
- Arthritis
- Pituitary failure
- Hepatomegaly
How do you diagnose haemochromatosis?
- Screen for haemochromatosis with transferrin saturation
- Abnormal LFTs - high ALT
- Raised ferritin (> 200 female, > 300 male)
- HFE genotype for mutation
- Liver biopsy
- Hepatic iron estimation
- Hepatic iron index > 1.9
What condition is haemochromatosis difficult to differentiate between?
Alcoholic haemosiderosis (alcoholic iron overload) - use HII to differentiate
What is primary biliary cholangitis
- Autoimmune disease of the liver
- It results from a slow, progressive destruction of the small bile ducts of the liver, causing bile and other toxins to build up in the liver (cholestasis)
What is the typical primary biliary cholangitis patient?
Middle aged female
Why is primary biliary cholangitis no longer called primary biliary cirrhosis?
Because not everyone is cirrhotic