LFT bloods Flashcards
Functions of the liver
conjugates and eliminates bile
clotting factor production
albumin synthesis
detox- fats, chemicals, meds
iron storage
bile production
What causes a low/ high albumin level in the blood?
Albumin- protein made in liver to maintain oncotic pressure
Hyper- servere dehydration
Hypo (2 categories)
-synethis (liver damage, inflammation, malnutrition, malignancy)
- excess loss (nephrotic syndrome, burns)
Name the LFT biomarkers.
Presence elsewhere in the body?
ALT
AST
ALP
GGT
Bilirubin
Albumin
Amylase
Clotting- PT
Autoimmune- Ig
- Bilirubin- break down of haem
Isolated rise -> Gilberts of haemolysis - ALT- liver only
AST- skeletal and cardiac muscle - ALP- present in biliary epithelial cells and bone.
Isolated increase may be bone pathology/ Paget’s disease - GGT- isolated rise indicates alcohol abuse
Can be used to monitor progression of liver disease - INR/ PT- assess clotting (fibrinogen, factors II, V, VII, X)- checked in warfarin, paracetamol OD
- Albumin- protein made in liver to maintain oncotic pressure
Hyper- server dehydration
Hypo- synethis (liver damage, inflammation, malnutrition)
excess loss (nephrotic syndrome, burns) - Autoimmune liver disease screening immunoglobulins- raised levels of IgM (PBC), IgA (alcohol), IgG (hepatitis)
- Amylase- check for pancreas function/ pancreatitis
What does an isolated AST mean?
MI- AST present in heart muscles
Haemolysis (malaria, sickle cell, thalassemia)
Biliary obstruction
Liver disease- jaundice
Renal failure- oedema
What does an isolated bilirubin rise mean in pre, hepatic and post-hepatic jaundice?
Pre-hepatic (usually unconjugated)- Haemolysis, Ineffective erythropoiesis
Hepatic (usually conjugated)- due to hepatitis or very severe liver failure
Chronic liver disease.
Post-hepatic- Obstructive jaundice secondary to intra- or extrahepatic causes
How is jaundice determined clinically?
Dark urine
Pale stool
Increased serum bilirubin
Causes of hepatocellular jaundice?
Pre-hepatic
Hepatic
Post-hepatic
Pre-hepatic: haemolytic anaemia
Hepatic- enzyme defects (gilberts syndrome, Crigler-syndrome), hepatitis, cirrhosis, drug-induced, alcohol
Post-hepatic- cholangitis, cholestasis, pancreatitis, cholangiocarcinoma
Causes of isolated ALP rises?
Paget’s disease- bone disorder, bones grow larger and become weaker
Causes of isolated GGT rises?
Alcohol abuse
Viral hepatitis
Epstein-Barr virus-
Enzyme-inducing drugs- statins, antiepileptics, antidepressants, PPIs
Low PT causes?
Warfarin medication
Liver clotting factor synthesis issue
Paracetamol OD
What is the fatty-liver pattern and its causes?
GGT 2-10 x ULN
Raised AST > ALT
Raised IgA
ALP normal
Macrocytosis- large RBC and higher MCV
Bilirubin normal
Albumin normal
Causes:
Obesity
Type-2 diabetes
Excessive alcohol
Explain the hepatocellular injury LFT ratios.
Which LFTs are raised in a hepatitic pattern?
Causes of hepatocellular injury?
AST:ALT ratio >2:1 indicative of acute alcohol related hepatitis.
AST:ALT >1 indicative of cirrhosis.
AST:ALT <1 suggestive chronic hepatitis/cholestatic syndromes.
Causes:
Hepatitis
Cirrhosis
Malignancy
Hepatotoxicity- meds OD/ SE
What is cholestasis?
Causes?
Impediment of bile flow through the biliary system- dark urine/ pale stools
Gallstones
Malignancy- strictures
Pregnancy
Medication
Intra/ extramural
PSC/ PBC
What LFTs are raised in a cholestatic picture?
ALP/ GGT
Bilibrubin
