Investigating liver disease Flashcards
Is icterus always present in liver disease?
No
Can have severe disease without icterus
Also present in serum before grossly visible
What should ALWAYS be done before taking a liver biopsy?
Coagulation profile
Which liver enzymes are hepatocellular markers?
ALT
AST
Which liver enzymes are cholestatic markers?
ALP
GGT
Give examples of liver function tests that are part of serum biochemistry
Serum proteins - esp albumin Glucose, urea, cholesterol Bilirubin (icterus) Bile acids (Ammonia)
What is a method of contrast radiography that can be used to investigate liver disease?
Portovenography
What is the only diagnostic investigation that can diagnose most liver diseases?
Liver biopsy
What are the 3 techniques of liver biopsy? (in terms of approach - not in terms of wedge biopsy etc)
Percutaneous - blind or US guided Tru-cut
Laparoscopy
Coeliotomy
Give examples of contraindications for percutaneous liver biopsy
Bleeding disorder Severe anaemia Small liver (unless US guided) Extrahepatic cholestasis Focal disease
What liver enzyme is mostly liver specific in small animals?
ALT - some muscle involvement
What are reactive hepatopathies?
An extrahepatic disease that causes liver enzyme eleevation
E.g. endocrine disease, hypoxia, GI disease
What are the 2 forms of ALP? Is the sensitivity good for small animals?
Liver - L-ALP
Bone - B-ALP
Good sensitivity for dogs, poor in cats
What breed of dog has a naturally high ALP activity?
Scottish terrier
Name 2 drugs that can cause an increase in liver enzymes
Steroids
Phenobarbitone
What causes pre-hepatic hyperbilirubinaemia?
Haemolysis
What causes hepatic hyperbilirubinaemia?
Hepatocyte dysfunction - decreased bilirubin uptake/conjugation/excretion
Intrahepatic cholestasis
What causes post-hepatic hyperbilirubinaemia?
Obstruction of extrahepatic bile ducts
How does decreased hepatocellular function affect biochemistry? (give examples of what is raised and decreased)
Raised - liver enzymes, bilirubin, bile acids, ammonia, immunoglobulins
Decreased - urea, albumin, cholesterol, glucose, coagulation factors
How does a PSS affect bile acids and bilirubin levels?
Increased bile acids
Bilirubin normal
Bile acids are produced by hepatocytes, and go into the intestine where 90% are reabsorbed and return to the liver via the portal vein. When is it pointless to measure bile acids?
If bilirubin already increased
What fasting serum bile level is considered abnormal, therefore indicating hepatobilliary pathology?
> 25-30mmol/l
Haematology with liver disease is often unremarkable, but what cells may you see?
Microcytosis
Ovalocytes - hepatic lipidosis in cats
Acanthocytes
