Liver Disease Flashcards
What are the main liver function tests and what are they associated with (detect)
AST, ALT: enzymes associated with hepatocyte damage
ALP: associated with cholangiocyte damage (i.e. Biliary disease)
Gamma GT: associated with cholangiocyte damage (i.e. Biliary disease)
What are ALT & AST?
Which is more specific for liver disease
Alanine aminotransferase
Aspartate aminotransferase
Enzymes that help process proteins
ALT more specific to liver disease
AST found in other types of cell (e.g. Heart, intestine, musc)
Why are ALP and Gamma GT used together in testing?
ALP elevated in large number of disorders affecting drainage of bile (e.g. Gallstones, tumour blocking common bile duct)
Also released from damages bone/placenta/intestine
So Gamma GT used as supplementary to ensure elevated ALP coming from liver/biliary tract
What 2 other substances can be measured as a marker of liver function
Albumin
Bilirubin
In what clinical condition(s) is albumin levels affected by
Reduced in advanced liver disease
Reduced more acutely in sepsis
In what clinical condition(s) is bilirubin levels affected by
Raised in Liver / biliary tract diseases
Relatively non-specific
What is Gamma GT
Gamma Glutamyl Transpeptidase
Often elevated in liver disorders (high senstivity, low specificity)
but not in diseases of bone/placenta/intestine
Also elevated in: Obesity Hyperlipidaemia Diabetes congestive cardiac failure Diseases of kidney, pancreas, prostate
ALT elevated:
Key questions to ask in history (acute, chronic)
Acute: age, sex, drugs, alcohol, travel, contacts, high risk behavious, autoimmunity, fever, cardiac probs, pregnancy
Chronic: age, sex, eyhnicity, BMI, lipids, diabetes, alcohol, travel, high risk behaviour, family history
Main conditions that cause abnormal LFTs in asymptomatic patients
Diabetes / metabolic syndrome
Excessive alcohol
Chronic hepatitis B or C
Drugs
ALT elevated:
Main tests to carry out in acute vs chronic hepatic illness
Acute: Hep A, B, C, E, EBV, CMV, TOXO, drugs screen, immunoglobulins, autoimmune profile, caeruloplasmin
Chronic: TFT, diabetic screen, Hep B, C, lipidsm immunoglobulins, autoimmune profile, ferritin, caeruloplasmin, alpha-1 antitrypsin, TTG
Elevated ALP (cholestatic illness): Questions to ask in history (acute vs chronic illness)
Acute: age, sex, drugs/antibiotics, family hx - gallstones, abdo pain, reg flags, jaundice
Chronic: family hx, matabolic syndrome, recurrent fever, ith/lethargy, dry eyes/mouth, colitis, pain, SOB/resp symptoms, CCF
Elevated ALP (cholestatic illness) Causes (acute vs chronic illness)
Acute: CBD stones/gallstones, tumour, pancreatic patholgy, drugs (augmentin, flucoxacillin), infiltration, SOD
Chronic: PBC, sclerosin cholangitis, NASH (non-alcoholic steatohepatitis), alpha 1 antitrypsin, sarcoid, amyloid, HIV
Investigation of cholestasis (if ALP raised)
Check Gamma GT - if isolated rise:
Stop alcohol, hepatotoxic drugs
Weight loss if BMI >25
Re-check LFTs
If ALP persistently raised: full liver screen
Dilated bile ducts: MRCP, ERCP
Non-dilated bile ducts: treat underlying disease, or liver biopsy if no diagnosis
Differentials for isolated rise in bilirubin (>22)
Gilberts:
Unconjugated hyperbilirubinaemia
Harmless
Haemolysis:
Unconjugated hyperbilirubinaemia
Splenomagaly, anaemia, DCT, hepatoglobin, reticulocyte count
Pathological
Causes of acute liver failure
Drugs:
Paracetamol, isoniazid, halothane, ecstasy
Viral:
Hep A, B, E
Wilsons disease
Autoimmune hepatitis
Reye’s syndrome
Cardiovascular:
Ischaemic hepatitis, Budd Chiari
Pregnancy (acute fatty liver)
Signs of chronic liver disease
Often none Spider naevi Asterixis / flap Relative hypotension (high total body Na: dont give saline) Oedema Jaundice Enlarged liver Splenomegaly Gynecomastia (oestrogen not broken down) Testicular atropphy Impotence
Signs of decompensation in cirrhosis
Ascites
Hepatic encephalopathy
Portal hypertension (variceal haemorrhage)
Other Causes of ascites
Peritoneal disease
Heart failure
Diabetic nephropathy
Hypoalbuminaemia of other causes
Management of bleeding varices
Prevention
Prophylactic antibiotics
Resuscitation (blood + platelets to stop bleeding)
Endoscopy: band ligation, sclerotherapy
Pharm: Terlipressin (vasoconstrictor)
Antibiotics: reduce infection and bacteria translocated to gut (also stops bleeding)
Balloon tamponade (temporary: if cant stop bleeding in endoscopy)
TIPS (portal shunt thru liver to reduce pressure in portal vein)
What are the main functions of the liver
Nutrition/ metabolic:
Stores glycogen, releases glucose, absorbs fat/fat soluble vitamins, manufactures cholesterol
Makes bile salts
(Lipids derived from cholesterol, dissolves dietary fats)
Makes bilirubin (Breakdown product of Hb)
Makes clotting factors
Immune functions (Kupfer cells engulf antigens - bacteria)
Detoxification: Drug excretion (sometimes activation) Alcohol breakdown
Manufactures proteins
(E.g. Albumin, binding proteins)
