Investigation of the liver Flashcards
Hepatocytes make up what percenatge of liver mass?
60%
What are the 3 functions of the liver in terms of lipids?
1) Lipoprotein and cholesterol synthesis
2) fatty acid metabolism
3) Bile acid synthesis
Which kinds of hormones are inactivated and excreted by the liver?
Steroid hormones
What metal is stored in the liver?
Iron
Where are amino acids metabollised?
Liver - urea cycle
Which 4 vitamins are stored and metabolised in the liver?
A, D, E, B12
What 6 measurements are included in LFTs?
1) Alkaline phosphatase
2) ALT (alanine aminotransferase)
3) Bilirubin
4) Albumin
5) Total protein
6) GGT (gamma glutamyl transferase)
What substance can be measured to assess the liver function of carbohydrate metabolism?
Glucose
What 3 things can be measured in the blood to check the livers protein function?
1) Albumin
2) urea
3) Porthrombin
What 3 things can be measure in the blood to check the livers lipid function?
1) Cholesterol
2) triglycerides
3) Bile acids
What 3 substances can be measured in the blood to check the livers excretion and detoxification function?
1) Bilirubin
2) Drugs
3) Steroid hormones
What substance in the blood can be measured as an indicator of the livers iron storage capacity?
Ferritin
What blood measurement would reflect the livers Vit K storage capacity?
Pro-thrombin time
What are the 4 broad available liver function tests?
1) Production of metabolites
2) Clearance of endogenous substances
3) Clearance of exogenous substances
4) Imaging, biopsy
What are the 2 aminotransferase enzymes found in the liver?
AST and ALT
Is AST or ALT more specific for liver?
ALT
Where else in the body is AST found? 2
Muscle and RBCs
What protein is a tumour marker for primary HCC?
Alpha fetoprotein
Where are ALT and AST found in the liver?
Within the hepatocytes
What has to occur for ALT and AST to be released?
Cellular damage
If there was impaired excretory function of the biliary tract what would be raised?
Conjugated bilirubin
Which 2 enzymes are synthesised by the cells lining the bile canaliculi?
1) Alk Phos
2) gamma GT
Why at a basic level would Alk Phos be raised?
Elevated due to increased production by cells lining the bile canaliculi and overflow into blood
What are the 4 causes of raised Alk Phos?
1) Cholestasis (intra or extra hepatic)
2) Infiltrative diseases
3) Space-occupying lesions (tumours)
4) Cirrhosis
What are the 4 sights of production of alk phos?
Liver, bone intestine, placenta
How are liver and bone isoenzymes seperated?
By electrophoresis
What would elevated gamma glutamyltransferase indicate?
Structural damage to the biliary tract
Give 7 causes of biliary tract damaged and thus elevated gamma GT?
1) Alcohol
2) Enzyme inducing agents
3) Fatty liver
4) Heart failure
5) Prostatic disease
6) Pancreatic disease (acute and chronic)
7) Kidney damage (ARF, nephrotic syndrome, rejection)
How was fibrosis historically measured?
1) Imaging
2) biopsy
3) Predictive scores
What are the 3 novel biochemical markers of fibrosis?
1) PIIINP
2) TIMP-1
3) Hyaluronic acid
What 3 types of bilirubin can be measured?
1) total
2) unconjugated
3) Conjugated
What kind of bilirubin would be raised in pre-hepatic and intrahepatic jaundice?
unconjugated
What kind of bilirubin would be raised in post-hepatic jaundice?
conjugated
What protein is unconjugated bilirubin bound to in the blood?
Albumin
What are the 2 aetiologies of pre hepatic jaundice?
1) Haemolysis
2) Ineffective erythropoiesis eg. spherocytosis
Give the 4 main obstructive causes of jaundice?
1) Gall stones
2) Biliary stricture
3) Cancer
4) Cholangitis
What would be the hepatic causes of raised unconjugated bilirubin?
1) Premicrosomal, microsomal or inhertied disorders of conjugation
What would be the hepatic causes of raised conjugated bilirubin?
Post microsomal or impaired excretion
Intrahepatic obstruction
Inherited disorders of excretion
Inborn errors of bilirubin metabolism lead to 1 of what 2 situation?
Decreased activity of UDP glucuronyl transferase - Gilbert’s, Crigler-Najjar
Reduced ability to excrete bilirubin glucuronide - Dubin-Johnson, ROTOR
If a jaundice patient has elevated ALT/AST and normal ALP, what is the most likely cause of the jaundice?
Hepatitis (damage to liver cells, bile ducts fine)
If a jaundice patient has normal ALT/AST and elevated ALP what is the likely cause of the jaundice?
Obstructive jaundice
Via which 2 ways can bilirubin be excreted?
Via the GIT as bilirubin glucuronide
Via the urine as urobilin (from urobilinogen)
In pre hepatic jaundice will urinary bilirubin be found?
No
What enzymes can be measured to determine whether raised conjugated bilirubin is due to obstruction or liver damage?
measure AST and ALT - tell you about liver damage
Measure AST - tells you about bile duct obstruction
In hepatic jaundice will urinary bilirubin be found?
Depends of the degree of obstruction
In post hepatic jaundice will urinary bilirubin be found?
Yes - dark urine and pale stools
Dark urine - cant get out by GIT so more excreted by urine
Pale stools - not excreted via bile into GIT
What specific tests could you do in viral hepatitis?
Serology for viral proteins
What specific tests could be carried out in chronic active and autoimmune hepatitis? 4
Anti smooth muscle Ab
Anti liver/kidney Ab
Anti micosomal Ab
Anti nuclear Ab
What antibody could you specifically test for in primary biliary cirrhosis?
Anti mitochondrial Ab
What 4 specific tests could you do in hereditary haemachromatosis?
1) Ferritin
2) Transferrin saturation
3) Liver biopsy
4) genetic testing
What specific protein could you look for in HCC?
Alpha - feto protein
What 4 specific tests could you carry out in Wilson’s disease?
1) Caeruloplasmin
2) Urine copper
3) Plasma copper
4) Liver biopsy
What 2 specific tests could you carry out in suspected alpha 1 anti trypsin deficiency?
A1 anti trypsin
genetic testing
Gynacoemastia, spider naevi, liver palms and testicular atrophy are all systemic effects of liver disease causes by what?
Oestrogen excess
What sign on the fingers is a sign of liver disease?
Clubbing
What are the 2 possible bone signs of liver disease?
1) Osteomalacia
2) Osteoporosis
What percentage of people with abnormal LFTs have liver disease?
1%
Give 5 causes of abnormal LFTs not caused by liver disease?
1) Alcohol related
2) Gilbert’s syndrome
3) Obesity
4) Diabetes
5) Side effects of medication
What would be the 4 reasons for measuring LFTs?
1) If patient showed signs and symptoms
2) In risk lifestyles (recent travel, drug use, obesity, alcohol)
3) To see if liver disease is present
4) to assess the severity of liver disease
What are the 3 endocrine secretions of the pancreas?
1) Insulin
2) Glucagon
3) Pancreatic polypeptide
What are the 2 exocrine secretions of the pancreas?
Bicarbonate and digestive enzymes
Give the 5 main disorders of the pancreas?
1) Acute pancreatitis
2) Chronic pancreatitis
3) Pancreatic insufficiency
4) CF
5) carcinoma of the pancreas
What are the 6 causes of acute pancreatitis?
1) Toxins
2) Alcohol
3) drugs
4) Hypertridglyceridaemia
5) Trauma and infections
6) Rare tumours, autoimmune, scorpion toxin
What is the characteristic pain of pancreatitis?
Sudden onset severe epigastric pain radiating to the back
Via what 3 things is a diagnosis of acute pancreatitis made?
1) Amylase/lipase - tests of exocrine function
2) Imaging
3) Clinical history
What lifestyle behaviour is often an important factor in chronic pancreatitis?
High alcohol intake
What are the 3 presenting clinical features of chronic pacnreatitis?
1) Abdominal pain
2) malabsorption - often the presenting feature
3) Imapired glucose tolerance
What is chronic pancreatitis?
Progressive loss of both islet cells and acinar tissue
Are tests of exocrine function of any value in chronic pancreatitis?
No except during acute exacerbations
How is a diagnosis of chronic pancreatitis made and managed?
1) Imaging
2) Pancreatic function tests for investigating insufficiency
3) Miscellaneous tests - Vit D, calciu, FBC, LFTs, glucose, lipids
What are the 2 direct (invasive) tests of pancreatic function?
1) Intubation to collect aspirates in the duodenum
2) Secretin, CCK, Lundh tests
What are the 3 indirect (non invasive) tests of pancreatic function?
1) Pancreatic enzyme analysis in stools (elastase)
2) trypsinogen (IRT) measured in blood for CF screening
3) Pancreolauryl and NBT-PABA test
