61 - Investigations of the liver and pancreas Flashcards
SER in liver responsible for
bilirubin conjugation + drug detox
Lysosomes in liver responsible for
intracellular scavengers (copper, ferritin)
Storage of ions and vitamins in liver - which ones?
Iron
A, D, E and B12 storage and metabolism
Whats are LFTs?
Alk. phos
ALT (alanine aminotransferase)
Bilirubin
Albumin
Total protein
GGT (y-glutamyl transferase)
Available other liver function tests?
Production of metabolites
Clearance of endogenous substances
Clearance of exogenous substances
Imaging, biopsy
Hepatocyte damage will release what
Aminotransferases: Alanine/ALT, Aspartate/AST, found intracellularly and only released by cell damage.
ALT is more specific for liver than AST, as AST is found in muscle and RBC too.
Tumour markers - a-fetoprotein is present in primary hepatocellular carcinoma.
Biliary tract damage would cause
Impaired excretory function -> increased conjugated bilirubin
Increased synthesis of enzymes by cells lining the bile canaliculi - ALP, yGT
Biliary tract damage - ALP
alk. phos
Elevated due to increased production by cells lining the bile canaliculi and overflow into blood
Due to: cholectasis (intra + extrahepatic), infiltrative diseases, tumours, cirrhosis
Made in liver, bone, intestine, placenta
Biliary tract damage - gamma glutamyltransferase
Can support a liver source of raised ALP
Elevated due to structural dmg
Biochemical markers of fibrosis
Imaging, biopsy and predictive scores
Novel markers: ELF Score
PIIINP
TIMP-1
Hyaluronic acid
Bilirubin
Excretory capacity of the liver and free flow of bile
Measured as total, uncojugated, conjugated
Jaundice at serum bilirubin >40-50 umol/l
Unconjugated bilirubin
Pre-hepatic and hepatic
Conjugated bilirubin
Post-hepatic (obstructive) and hepatic
Bilirubin metabolism
slide 21
Pre-hepatic aetiology for hyperbilirubinaemia
Haemolysis e.g. Rh incompatibility
Ineffective EPO e.g. spherocytosis
Post hepatic (obstructive) aetiology for hyperbilirubinaemia
Gallstones
Biliary stricture
Cancer e.g. cholangiocarcinoma, head of pancreas
Cholangitis
Unconjugated bilirubin aetiology for hyperbilirubinaemia
pre-microsomal
microsomal
inherited disorders of conjugation e.g. Gilberts, Crigler-Najjar
Conjugated bilirubin aetiology for hyperbilirubinaemia
Post-microsomal/impaired excretion
Intrahepatic obstruction
Inherited disorders of excretion e.g. Dubin-johnson, Rotor
Gilbert’s is due to… what is name of other disease affected in similar way
Decreased activity of UDP glucuronyl transferase
Crigler-Najjar
Dubin-Johnson and ROTOR is due to….
Reduced ability to excrete bilirubin glucuronide
Blood tests in the differential diagnosis of jaundice
AST/ALT high & normal ALP = hepatitis
AST/ALT normal & elevated ALP = obstructive jaundice
Urine tests in the differential diagnosis of jaundice - prehepatic
Prehepatic: unconjugated bilirubin - no urinary bilirubin
Urine tests in the differential diagnosis of jaundice - hepatic
Hepatocellular
Variable based on obstruction due to disease or inflammatory oedema
Urine tests in the differential diagnosis of jaundice - post-hepatic
Obstruction
Dark urine and pale stools
Specific tests for Wilson’s disease
Caeruloplasmin, urine copper, plasma copper, liver biopsy
Specific test for hepatocellular cancer
AFP
Systemic effects of liver disease
Jaundice Oestrogen excess Bruising Pigmentation Clubbing Dependent oedema Ascites Encephalopathy Osteomalacia/porosis
Oestrogen excess
Gynaecomastia
Spider naevi
Liver palms
Testicular atrophy
Endocrine secretions of pancreas
Islets of langerhans
Insulin, glucagon
Pancreatic polypeptide
Exocrine secretions of pancreas
Bicarb
Digestive enzymes: trypsin, chymotrypsin & elastase, carboxypeptidases, amylase, lipase
Acute pancreatitis - aetiology
Acute necrotising liquefaction
Aetiology: gallstones, -OH, drugs, hypertiglyceridaemia, trauma, infectious, rare tumours, autoimmune, scorpion toxins
Acute pancreatitis - symptoms
Severe epigastric pain
Sudden onset
Radiating to back
Acute pancreatitis - biochemical features
Uraemia Hypoalbuminaemia Hypocalcaemia Hyperglycaemia Metabolic acidosis Abnormal LFTs
Acute pancreatitis - diagnosis
Amylase or lipase
Imaging
Clinical history
Chronic pancreatitis - presentation
Ab pain
Malabsorption
Impaired glucose tolerance
Alcohol often an important factor
Chronic pancreatitis - diagnosis and management
Imaging
Pancreatic function test
Misc: vit D, Ca, FBC, LFTs, glucose, lipids
Direct tests for pancreas
Intubation to collect aspirates in duodenum
Secretin, CCK, Lundh tests
Indirect tests for pancreas
Pancreatic enzyme analysis in stools (elastase)
Trypsinogen (IRT) measured in blood in CF screening
Pancreolauryl & NBT-PABA tests
