Liver problems Flashcards
(33 cards)
What does the organ do in a double organ transplant?
The liver can become tolerised so the person won’t reject the liver.
It can also protect the second organ if it is from the same donor against rejection.
Why does liver disease go undetected?
The liver regenerates and has massive functional reserve.
Person won’t see loss of normal function if 25% of liver is removed, so don’t realise they have liver disease until it is extreme - cirrhosis, at risk of developing liver cancer.
What are the symptoms of cirrhosis?
Scarring:
Renal failure
Varices in oesophagus
Ascites
Splenomegaly
Portal hypertension
How do the symptoms of cirrhosis cause effects?
Hypertension in blood vessels to liver, which causes altered blood flow to other organs.
Hypertension also forces tissue fluid into the abdomen - ascites acummulation.
Causes renal failure, splenomegaly, varices (bulge) in oesophagus - bleed easily, as a sick liver doesn’t make coagulation factors.
What are the main causes of cirrhosis?
Fatty liver disease and alcohol abuse.
What is viral hepatitis?
Viruses selectivity infect hepatocytes.
Hepatitis B and C are particularly damaging.
Hep B vaccines can help combat this, but can inadvertently causes hepatitis C and causes cirrhosis.
How does hepatitis occur?
Viruses selectively infect hepatocytes.
Very strong immune response causes severe hepatitis.
The immune system kills the infected hepatocytes.
Some viruses are cleared but some cause chronic infection and immune response, which drives fibrosis and end stage liver failure.
What is MALSD?
Metabolic associated liver disease.
Ranges from fat to hepatitis and fibrosis.
Caused by obesity, diabetes, dyslipidaemia, hypertension.
Can cause insulin resistance, lipotoxicity, oxidant stress, apoptosis, inflammation, scarring risk.
What is acute liver disease?
Can be caused by alcohol binge, or a bad drug reaction.
The injury is removed, and the liver regenerates.
But the injury can persist, e.g. chronic Hep C, where the immune response and inflammation becomes chronic and damages tissue, by activating stellate cells to cause scarring.
What is jaundice?
Yellow discolouration of the skin, eye and other tissues.
Due to a build-up of bilirubin in tissue fluids and bloodstream.
In excess of 2mg/ml.
How can jaundice be detected?
Increased levels of aspartate transaminases and alanine transaminases shows that the hepatocytes are damaged.
Alkaline phosphatase and gamma glutamyl transferase (gGT) also shows biliary disease.
Albumin levels would decrease.
How can jaundice be detected through antibodies?
Autoantibody levels might be increased, which target the biliary tree or hepatocytes.
In advanced liver disease, there may be altered white blood cell count.
Viral DNA or antibodies in the blood can indicate hepatitis virus.
How can jaundice be detected by metabolic indicators?
Metabolic liver disease, dyslipidaemia and type 2 diabetes can all indicate liver disease.
As tumours grow, tumour specific molecules like alpha feta protein increase, which indicates liver cancer.
What are technologies for detecting liver disease?
MRI or CT imaging to see the tumours.
Ultrasound using a fibroscan, the faster the sound waves bounce back the more scarred the liver is.
What is prothrombin time?
Can measure how fast the liver makes clotting factors by measuring how fast blood clots.
Increased prothrombin time shows the blood clotting is slow.
What is bilirubin?
A product of haem catabolism.
It comes from red blood cells, myoglobin, cytochromes and peroxidases.
It is an orange/yellow pigment.
Lots of bile is needed for excretion of substances and for digestion, some is lost by the faecal route.
So bile salts are recycled often in the day.
What do Kupffer cells do for bilirubin?
The macrophages break the RBCs into heme.
Heme is modified by heme oxygenase, to form green biliverdin. Fe2+ is kept, CO is removed.
Biliverdin is further reduced by biliverdin reductase to form the orange bilirubin.
How does bilirubin go to the liver?
Unconjugated bilirubin is not water soluble, so it is complexed to albumin so it can travel in the blood to the liver.
In the hepatocytes, it is conjugated with glucoronic acid by UDP glucooronyltransferase.
Conjugated bilirubin is water soluble.
What can conjugated bilirubin do?
Conjugated bilirubin is excreted as bile from the bile duct.
Some bile is used to digest food and for lipid emulsification.
It can be metabolised by b-glucuronidase in the gut in bacterial or epithelial cells, to form urobilinogens.
Some urobilinogens are reabsorbed and sent back to the liver via the portal vein, some are excreted in urine.
What is haemochromatosis?
Increased serum ferritin suggests there is too much iron in the liver, which causes oxidative injury.
This damages the liver and leads to cirrhosis.
But there are specific gene mutations in haemochromatosis, so this can indicate if disease is this or something else liver related.
What are the different forms of jaundice?
Pre-hepatic upstream of liver
Intrahepatic - liver
Extrahepatic - downstream of liver
All linked to haem metabolism, which makes the pigments.
What is pre-hepatic jaundice?
The macrophages eat the RBCs as normal.
Levels of unconjugated bilirubin are elevated, which shows the issues are before the liver.
Associated with fragile RBCs rupturing - haemolysis.
There are normal AST/ALT and normal AP/gGT.
What are the causes of fragile RBCs?
Haemolytic anaemia - RBC destruction.
Paroxysmal nocturnal haemoaglobulinurea (PNS), genetic.
Sickle cell disease - genetic, variant haemoglobin,
Malaria.
Can have inherited diseases which alter the phospholipid membranes of RBCs.
What are the liver symptoms in anaemias?
Bilirubin causes gallstones - darker urine, elevated unconjugated bilirubin.
Enlarged liver - thrombisis, increased transaminases.
Iron overload due to high RBC turnover.
Splenomegaly.
Coagulation deficit.
MRI shows defections.
