LFTs

Question 1

What are the homeostatic functions of the liver?

Answer 1

Gluconeogenesis
Protein metabolism.
Fat metabolism    
Bilirubin metabolism.                                        
Acid/Base Balance.
Heat production.

Question 2

What is stored within the liver?

Answer 2

Glycogen.
Iron.
Fat.                                              
Vitamins A, B12, D, E, K.
Copper and Selenium.

Question 3

What are the metabolic functions of the liver?

Answer 3

Amino acid metabolism creates Ammonia
Ammonia + CO2 = UREA
UREA excreted renally.
Nucleoprotein from worn out cells is broken down to form uric acid, which is renally excreted.

The liver processes hormones such as insulin, glucagon, oestrogens and growth hormones.
It is the most important site for the metabolism of drugs and alcohol. Fat-soluble drugs are converted to water-soluble substances to facilitate excretion in bile or urine.

Question 4

what are the synthetic functions of the liver

Answer 4

Albumin.
Coagulation factors.
Acute Phase Proteins.
Vitamin A (but not in the building it sense)
Bile.

Question 5

Define Pre-Hepatic Jaundice

Answer 5

Increased destruction of red blood cells = increased amounts of bilirubin.
red cell abnormalities (sickle cell), hemolysing diseases such as malaria, very rarely drugs such as levodopa, NSAIDs and some antibiotics.

Question 6

Define Hepatocellular Jaundice.

Answer 6

Results from the livers inability to transport bilirubin into bile. Causes are related to liver cell damage. For example alcohol use, hepatitis, potential certain drugs (salicylates, oral contraceptives, rifampicin).

Question 7

Define post hepatic jaundice

Answer 7

Obstructive Jaundice.
Results from obstruction to the excretion of bilirubin.

Causes of large duct obstruction include gallstones, biliary duct strictures, sclerosing cholangitis (inflammation of the bile ducts) and carcinoma (particularly head of pancreas).

Causes of small duct obstruction include, damage to liver cells (by drugs and alcohol), viral hepatitis, bacterial infections and primary biliary cirrhosis.

Question 8

Define Hepatitis

Answer 8

Inflamation of the liver with accompanying liver cell damage or death. Associated with viral infection, certain drugs or auto-immune

Question 9

symptoms of hepatitis

Answer 9

Symptoms include jaundice, nausea, vomiting, loss of appetite, tenderness in the right upper abdomen, aching muscles, and joint pain. In severe cases, liver failure may result.

Question 10

Define Cirrhosis

Answer 10

chronic damage to liver cells and the eventual formation of scar tissue (fibrosis).

Question 11

Symptoms of cirrhosis

Answer 11

mild jaundice, oedema, confusion and haematemasis.

Question 12

What causes a rise in ALT/AST

Answer 12

Hepatitis (viral or auto-immune) 
Excessive alcohol intake or alcohol related liver disease 
Liver inflammation. 
Inherited liver diseases 
Liver tumours 
Heart failure

Question 13

What is ALT

Answer 13

Alanine aminotransferase (ALT)
an enzyme necessary for energy production.
It is present in a number of tissues, including the liver, heart, and skeletal muscles, but is found in the highest concentration in the liver.

Question 14

What conditions would you expect a significant rise in ALT

Answer 14

The highest ALT levels are associated with acute and massive liver cell necrosis. E.g acute viral hepatitis, acute shock, paracetamol OD)
A persistent moderately raised ALT (10 x normal) is associated with chronic liver disease.

Question 15

What is AST

Answer 15

Aspartate aminotransferase (AST)
] is also necessary for energy production
It is found primarily in the liver, but is in other organs as well. High levels in the blood can indicate liver disease, but may also indicate other systemic diseases.

Question 16

What causes a rise in ALP and GGT

Answer 16

Primary biliary cirrhosis, 
Fatty liver (steatosis), 
Alcoholic liver disease, 
Liver inflammation,  
Liver tumours, 
Gallstones or gall bladder problems.

Question 17

Define ALP and GGT

Answer 17

GGT and ALP are also called cholestatic liver enzymes. Chloestasis is a term used for partial or full blockage of the bile ducts. If the bile duct is inflamed or damaged, GGT and ALP back up into the liver and then the blood.

Question 18

What is GGT

Answer 18

Gamma-glutamyltranspeptidase (GGT) is found in the liver. The normal range is 5 – 80 U/L. GGT levels may be elevated in patients taking phenytoin and can be lower in those taking oral contraceptives.
Elevated GGT levels are induced by alcohol so it can be used to monitor alcohol abuse (in the absence of liver disease)

Question 19

What is ALP

Answer 19

Alkaline phosphatase (ALP) is formed in the bones, intestines (cells lining the bile duct), kidneys and placenta as well as the liver.

Question 20

What is ALP

Answer 20

Alkaline phosphatase (ALP) is formed in the bones, intestines (cells lining the bile duct), kidneys and placenta as well as the liver. 
Diseases of impaired bile formation - cholestatic

Question 21

If ALP is raised but GGT is normal

Answer 21

Bone disease or metastatic spread

Question 22

What are the two forms of bilirubin

Answer 22

Unconjugated - formed in the spleen and is not water-soluble

Conjugated - soluble form, converted in the liver from the unconjugated form. Secreted into bile

Question 23

What are the two forms of bilirubin

Answer 23

Unconjugated - formed in the spleen and is not water-soluble

Conjugated - soluble form, converted in the liver from the unconjugated form. Secreted into bile

Question 24

What can cause a rise in bilirubin?

Answer 24

Haemolysis
Gilberts syndrome
Certain drugs - anabolic steroids, antibiotics, antimalarials, ascorbic acid, codeine, adrenaline, oral contraceptives, vitamin A

Question 25

In split monitoring of bilirubin - what causes a rise in unconjugated bilirubin

Answer 25

Unconjugated (indirect-reacting) bilirubin. The normal is < 10 umol/L. Elevated levels of indirect reacting bilirubin are usually caused by haemolysis and impaired conjugation from liver cell dysfunction (e.g. hepatitis)

Question 26

In split monitoring of bilirubin - what causes a rise in conjugated bilirubin

Answer 26

Conjugated (direct reacting) bilirubin testing measures bilirubin made in the liver. The normal value is < 7 umol/L. Elevated levels typically result from obstruction either within the liver (intrahepatic) or a source outside the liver such as gallstones or cancer of the pancreas.

Question 27

Isolated rise in Bilirubin?

Answer 27

Gilberts syndrome | Haemolysis - specifically in patients with anaemia

Question 28

Rise in ALP/GGT - Cholestatic

Answer 28

Common – Primary biliary cirrhosis, Primary sclerosing cholangitis, biliary obstruction, hepatic congestion, drug-induced liver injury Isolated raised ALP may be Vit D deficiency

Question 29

Rise in AST/ALT

Answer 29

Hepatic – predominantly raised ALT and AST indicate hepatocellular liver injury (hepatitis) Common – viral, NAFLD, Alcohol-Related LD, AutoImmune Hepatitis, drug-induced

Question 30

What are the causes of acute liver failure?

Answer 30

``` Viral Drugs and toxins Pregnancy Metabolic Other ```

Question 31

Causes of chronic liver disease

Answer 31

``` Alcoholic liver disease Primary biliary cirrhosis Sclerosing cholangitis Post viral hepatitis Cryptogenic cirrhosis ```

Question 32

What is the clinical significance of portal hypertension

Answer 32

Hypertension within the portal vein, causing back pressure within the abdomen Portal hypertension leads to increased hydrostatic pressure leading to ascites, oedema and potential for oesophageal varices NB. Ascites and oedema are also related to ; Decreased renal blood flow = sodium and water retention. Impaired synthesis of albumin = reduced osmotic pressure.