Liver Disease CPC Lecture Flashcards
What is the reference range for bilirubin?
5-17 micromol/L
What is ALT? AST? GGT?
- Alanine Aminotransferase
- Aspartate Aminotransferase
- Gamma-glutamyltransferase
These are enzymes. Many more could be measured.
Explain the anatomy of liver lobules.
Sinusoids are lined by epithelial cells.
Hepatic portal vein to central vein is where everything is removed
Portal veins go to gut
Central vein goes to IVC
Describe this picture.
Hepatocytes are born proximal to the sinusoid and die distal to it.
What does the portal triad consist of?
- Portal vein
- Hepatic artery
- Bile duct
What might you see on US in someone with high bilirubin?
Tumour of head of pancreas
Gall stones
What other bloods would you do in someone with high bilirubin?
Bloods - amylase (pancreatic function), repeat LFTs, FBC
Viral screen - hepatitis
How are causes of high bilirubin categorised?(3)
Pre-hepatic e.g. haemolysis
Hepatic -
Post-hepatic - obstructive jaundice
Why are neonates commonly jaundiced? How are they treated?
Unconjugated bilirubin - lack of light so giive phototherapy?
What condition causes high fasting bilirubin?
Gilbert’s
How is Gilbert’s inherited?
Recessive
What is the cause of jaundice in paediatric cases?
- It usually is, but the bilirubin should be unconjugated as the cause is usually liver immaturity coupled with a fall in the haemoglobin early in life.
- If it doesn’t settle, other rare causes should be looked for including hypothyroidism, other causes of haemolysis (including a Coombes test or DAT), and the unconjugated bilirubin will be useful.
What reaction is used to measure serum bilirubin (conjugated)?
The van den Bergh reaction
The addition of methanol causes a complete reaction, which measures total bilirubin (conjugated plus unconjugated); the difference measures unconjugated bilirubin (an indirect reaction).
Describe the pathophysiology of Gilberts.
- UDP glucuronyl transferase activity reduced to 30%
- Unconjugated bilirubin tightly albumin bound and does NOT enter urine.
- Worsened by fasting
- Effects of phenobarb : reduces levels
Which marker is most representative of liver function?
- Prothrombin time (liver makes clotting factors) - if PT rises by one second per hour then you might need to refer pt for a transplant (normal PT - 11-13.5)
- Albumin is also useful
- Bilirubin
Other tests are enzymes and not truly tests of liver function (rather, damage).
How is paracetamol overdose treated?
N-acyetyl-cysteine
What are the
- Pre-hepatic (Gilberts, heamolysis)
- Hepatic
- Viral hepatitis
- Alcoholic hepatitis
- Cirrhosis
- Post-hepatic - gallstones, pancreatic Ca
If AST and ALT are high, what does this suggest(in an alcoholic)?
Suggests there is hepatocyte damage
High Alk Phos would mean obstructive causes instead.
Describe Hep A.
Nothing hammens for 3 weeks
At 4 weeks you make antibodies
Either kills you or nothing happens.
Once IgG is formed you are immune.
Hep A is a one-off infection.
There is no carrier status for Hepatitis A virus
Hep B
- Blood transmission e.g. sharing needles
- E antigen and surface antigen replicate so you make many virions
- Antibodies are made - IgM gets rid of E antigen (called “core” antigen)
- Immunity is established after 6 months and they become immune from second attack.
- Vaccination is only against surface antigens.
Can you have a Hep B carrier?
Yes
Some people have a subclincal illness from not clearing the antigen - remain secreting active virus for 10-20 years but are immune against one of the antigens.
What are the 3 stages of ALD?
- Fatty change - small and large
- Alcoholic hepatitis - Mallory-Denk bodies (ballooning of hepatocytes) and neutrophil infiltration.
- Cirrhosis - scarring
All 3 may coexist.
Acetaldehyde is what is actually damaging to hepatocytes, not the alcohol itself.
List 5 histological features of alcoholic hepatitis.
defining histological features:
- liver cell damage
- inflammation
- fibrosis
associated histological features:
- fatty change
- megamitochondria
What is the main cause of NASH?
NASH (Non Alcoholic Steato Hepatitis)
Insulin resistance (diabetes and obesity)
Why is Pabrinex yellow?
Riboflavin (B2) is yellow
How do you treat alcoholic liver disease?
- Supportive.
- Stop alcohol.
- Nutrition:
- Vitamins (esp B1, thiamine)
- Occasionally steroids.
Which disease is caused by B1 deficiency?
- A.Rickets
- B.Scurvy
- C.Pernicious anaemia
- D.Beri-Beri
- E.Pellagra
- F.Neural tube defects
Beri-beri
A.Rickets - Vit D
B.Scurvy - Vit C
C.Pernicious anaemia - B12
D.Beri-Beri B1
E.Pellagra B3
F.Neural tube defects Folate
What do these signify?
- Palmar erythema
- Spider naevi
- Dupytren’s contracture
- Gynaecomastia
Chronic stable liver disease
What is a visible vein on anterioir abdminal wall?
Pressure in portal venous system causes portal hypertension which leads to collateral veins growing from umbilicus.
Ductuc venosus REOPENS - if the high pressure is longstanding
What are the consequences fof portal hypertension (on examination)?
- Visible abdominal VEINS - blood can pass azygos vein up oesophagus to bypass liver
- Splenic vein drains into the portal vessel - SPLENOMEGALY is an important feature of portal hypertension.
- SHIFTING DULLNESS - ascites
This is the TRIAD of PORTAL HYPERTENSION
How do you stop oesophageal variceal bleeding in an emergency?
Sengstaken-Blakemore tube (this is a nasogastric tube with a balloon at the end)
They would vomit whole blood volume in 15 mins so must be done before endoscopy.
What is a flap a feature of?
- A.Jaundice
- B.Hepatitis
- C.Chronic stable liver disease
- D.Portal hypertension.
- E.Liver failure
- F.Obstruction of the bile ducts
Liver failure - waste such as ammonia is not cleared causing encephalopathy.
What are some features of liver failure which cause a flap?
- Failed synthetic function
- Failed clotting factor and albumin
- Failed clearance of bilirubin
- Failed clearance of ammonia
- (encephalopathy)
What are the hallmarks of cirrhosis?
- Involves whole liver
- Nodules consist of regenerating hepatocytes
- Pallor
NB: Fibrous scar tissue forms joining portal tract and central vein - this is intrahepatic shunting - blood no longer goes past the hepatocytes. Avoiding all hepatocytes prevents clearing toxins –> encephalopathy.
How can you treat portal hypertension surgically?
TIPS - hole is drilled from portal to central vein causing pressure to fall in oesophageal gastric junction. They will no longer vomit blood but instead encephalopathy will result (but only if the TIPS hole is too big).
But there is no treatment other than LIVER TRANSPLANT.
List some porto-systemic anastomoses
- Oesophageal varices
- Rectal varices
- Umbilical vein recanalising
- Spleno-renal shunt
What is the cause of itching? (in a patient with jaundice, cachexia, palpable gall bladder, scratch marks)
- A.Jaundice
- B.Hepatitis
- C.Chronic stable liver disease
- D.Portal hypertension.
- E.Liver failure
- F.Obstruction of the bile ducts
Bile duct obstruction
Itching - colourless bile salts start to leak into circulation due to obstruction.
What does the absence of urobilinogen signify?
Urobilinogen is present in urine
If no urobilinogen in urine then obstructive jaundice
Stercobilinogen and urobilinogen are theh same thing in different locations.
What is Courvoisier’s Law?
If you can feel the gall bladder then the cause is pancreatic cancer.
Unlikely to be gall stones - if you have stones the gall bladder is small and fibrotic and cannot become large.
Name two common causes of obstructive jaundice.
Pancreatic cancer
Gallstones
