Liver pathologies and ano-rectal disorders Flashcards
What are the 3 pathways of lipid metabolism in the liver?
Reverse transport pathway (HDL)
Exogenous pathway (Chylomicrons)
Endogenous pathway (LDL)
Describe the metabolism of lipids in the liver?
Bile digests lipids in the gut, forming chylomicrons
Remnant receptors on liver take in chylomicrons
VLDL and HDL released by the liver
VLDL converted to LDL by lipoprotein lipase and taken up by the liver
HDL delivers cholesterol to tissue that needs it
Describe the metabolism of protein in the liver
Proteins are broken down into amino acids in the small intestine
Hepatocytes transport amino acids which are metabolised via the krebs cycle, forming hormones, neurotransmitters, plasma protein, nucleotides and ammonia
Describe the metabolism of ammonia in the liver
Ammonia is detoxified in the liver by conversion to urea by the krebs cycle, which is consumed in the conversion of glutamate to glutamine, a reaction that depends upon glutamine sythetase
Describe the metabolism of vitamin D by the liver
Vitamin D is metabolised to cholecalciferol and then to 25-hydroxy-cholecalciferol
What are the 3 phases of drug metabolism in the liver?
Phase I
Phase II
Phase III
What occurs in phase I of drug metabolism?
The drug can undergo oxidation, reduction and hydrolysis by cytochrome P450 in the endoplasmic reticulum
Some of these P450 proteins include CYP1, 2, 3 and 3A4
What occurs in phase II of drug metabolism?
The drug undergoes conjugation in the cytoplasm of hepatocytes
These conjugation processes include addition of glucuronic acid, sulphate, acetate, glycine or glutathione
What occurs in phase III of drug metabolism?
The drug is secreted into the bile, mediated by ATP
What is the function of albumin?
It is involves in the transport of insoluble molecules such as bilirubin, hormones and fatty acids in the blood
What are some proteins that are synthesised by the liver?
Ferritin
Caeruloplasmin
Transferrin
Ferritin
Alpha 1 anti-trypsin
CRP
AFP
Complement system components
Fibrinogen
Vitamin K dependant coagulation factors (X, IX, VII, II, V)
What role does the liver play in bile synthesis?
Primary bile is made up in the liver
Secondary bile acids are absorbed by the liver
What are some components of bile?
Phospholipids
Cholesterol
Bilirubin
Conjugated drugs
Electrolytes (e.g. Na+, Cl-, HCO3-, Cu)
Describe the pathway from formation to excretion of bilirubin
Haem -> In spleen
Biliverdin ->
Unconjugated bilirubin -> In blood
Conjugated bilirubin -> In liver
Urobilinogen -> In intestines and kidneys
Urobilin (kidneys) or Sterocobilin (Intestine)
Describe the role of the liver in immune response
The liver contains Kupffer cells which phagocytose gut pathogens
It also produces interleukins and tumour necrosis factors
What is liver cirrhosis?
The development of regenerative nodules, surrounded by fibrous bands in response to chronic liver injury
Describe the pathophysiology of liver cirrhosis
Injury causes inflammation, matrix deposition, parenchymal cell death and angiogenesis
Damage to cells releases cell contents and ROS which activates stellate cells
Stellate cells release CCL2 which activates macrophages
Phagocytosis of liver cells releases pro-inflammatory mediators which activates neutrophils, and releases TGFß which transdifferentiate stellate cells into myofibroblasts
Myofibroblasts release collagen and alpha-SMA causing scarring, which neutrophils cause damage
What occurs when chronic injury to the liver is stopped during fibrosis pathophysiology?
There is a decrease in MMP release from immune cells, which causes net matrix degradation
How can liver cirrhosis lead to portal hypertension?
An increase in type I and III collagen as well as angiogenesis and sinusoidal remodelling leads to increased sinusoidal resistance
What are some general symptoms of liver cirrhosis?
Jaundice
Fever
Loss of body hair
What are some presentations of compensated liver disease?
Xanthelasma
Parotid enlargement
Spider naevi
Gynaecomastia
Splenomegaly
Liver palms
Scratch marks
Testicular atrophy
Perpura pigmented ulcers
What is meant by liver palms?
Clubbing
Duputren’s contracture
Xanthoma
What are some presentations of decompensated liver disease?
Neurological conditions (e.g. disorientation, drowsiness, stroke)
Encephalopathy - Hepatic flap
Fetor hepaticus
Ascites
Caput medusae
Oedema
What are some investigations in liver cirrhosis?
Liver biopsy
Serum markers
Elastography
What are some of the serum markers that can be used in liver cirrhosis?
Albumin - Decreased in end stage
Prothrombin time - Decrease synthesis of clotting factors
Bilirubin - Increased in end stage cirrhosis due to decreased clearance
Platelets - Decreased thrombopoetin decreases megakaryocytic growth
What occurs in alcoholic liver disease?
Ethanol is absorbed into hepatocytes, altering their micrometabolism, especially their fat metabolism, which causes cell injury and death, manifested by formation of Mallory’s hyalin
Describe the progression of alcoholic liver disease
Fatty liver
Hepatitis
Fibrosis
Cirrhosis
How will 2-3 days of drinking alcohol affect the liver?
Cause reversible fatty liver
How will 4-6 weeks of chronic high alcohol intake affect the liver?
Cause reversible hepatitis
How will months of chronic high alcohol intake affect the liver?
Cause reducible liver fibrosis
How will years of chronic high alcohol intake affect the liver?
Cause irreversible cirrhosis
What occurs in fatty liver disease?
There in an increased number of fat vacuoles within the hepatocytes
What are some possible complications of alcoholic liver disease?
Cirrhosis
Portal hypertension
Malnutrition
Hepatocellular carcinoma
Social disintegration
How are units of alcohol calculated?
. Volume (mls) x ABV (%)
. ———————————
. 1000
What does CAGE stand for in alcohol misuse screening?
do you think you should (C)ut down
do you get (A)nnoyed by criticism of your intake
do you feel (G)uilty about your drinking
do you use alcohol as an (E)ye opener
What is the alcohol misuse screening test used in A&E?
PAT (Paddington Alcohol Test)
What is the cycle of change in alcohol misuse?
1 - Pre-contemplation
2- Contemplation
3 - Preparation
4 - Action
5 - Maintenance
6 - Established change or Relapse
What are the 2 stages of alcoholism treatment?
Detox
Maintenance of abstinence
What are some methods of abstinence maintenance in alcohol misuse?
White knuckling
Peer support (AA)
Disulfiram
Acomprasate
How does disulfiram work?
It creates an increase ethanol sensitivity and so causes adverse effects if alcohol in taken in
What is non-alcoholic fatty liver disease?
This is a spectrum of disease ranging from steatosis to steatohapatitis to fibrosis and cirrhosis, with an identical pathology to alcoholic liver disease
What causes non-alcoholic fatty liver disease?
Increased fat intake and insulin resistance
How is steatohepatitis pathologically characterised?
Inflammation
Hepatocyte degeneration
Ballooning
Mallory bodies
Eventual fibrosis
How is simple steatosis diagnosed in NAFLD?
Ultrasound
What is NASH?
Non-Alcoholic SteatoHepatitis
How is NASH diagnosed?
Liver biopsy
What is the management of simple steatosis in NAFLD?
Weight loss
Exercise
What is the management of NASH in NAFLD?
Weight loss
Exercise
Some experimental treatments
What are some viruses that can cause hepatitis?
Hepatitis A, B, C, D, E
Epstein-Barr Virus (EBV)
Yellow fever virus
Hepres Simplex Virus (HSV)
Cytomegalovirus (CMV)
How is hepatitis A spread?
Faecal-oral route
Who is most at risk of hepatitis A?
Children and young adults
Those in the tropics
Those with poor sanitation
How will hepatitis A show on LFTs?
High ALT and AST
Possible high bilirubin
How is a diagnosis of Hepatitis A made?
Blood clotting testing for HAV IgM
Does hepatitis A cause acute or chronic hepatitis?
Acute
Does hepatitis B cause acute or chronic hepatitis?
Both
How is hepatitis B transmitted?
Vertical transmission (Mother to child)
Blood
Sexually
Who is most at risk of hepatitis B?
People born in high prevalence areas
Children of infected women
PWID
People who have many partners in high prevalence areas
Men who have sex with men
What is the incubation period for hepatitis B?
30-180 days
When would a patients with Hepatitis B require treatment?
If there’s acute liver failure, coagulopathy or prolonged course of illness (>4 weeks)
What are the 7 diagnostic markers of hepatitis B?
HBsAg = Viral surface antigen
Anti-HBs = Antibody to surface antigen
HBeAg = Viral replication protein
Anti-HBe = Antibody to replication protein
HBcAg = Viral core antigen
Anti-HBc = Antibody to core antigen
HBV DNA = DNA of hepatitis B
How is a neonate treated for hepatitis B?
Immunoglobulin infusion and vaccination
What are the 2 nucleoside analogues for hepatitis B treatment in adults?
Tenofivir
Entecavir
Does hepatitis C cause acute or chronic infection?
Chronic
How many genotypes of hepatitis C are there and which are most common in the UK?
6 genotypes
I and III are most dominant in UK
How is hepatitis C transmitted?
Blood
Sexual (rare)
What are the main risk factors of hepatitis C?
PWID
Transfusions in the developing world
Tattoos in the developing world
Who is offered treatment in hepatitis C?
Everyone who will accept, as there is a low rate of spontaneous clearance
What are the 3 classes of drugs that can be used in hepatitis C treatment?
Protease inhibitors
Polymerase inhibitors
NS5A inhibitors
How is hepatitis C diagnosed?
HCV IgG = Indicated exposure
HCV RNA = Indicates active infection
How does hepatitis D cause infection?
It causes progressive or acute hepatitis in patients with pre-existing HBV infection as it required the HBsAg
What are the treatment options for hepatitis D?
Pegylated interferon - 48 weeks treatment
Bulveritide
Is hepatitis E acute or chronic?
Acute
What are some symptoms of hepatitis E?
Jaundice
Nausea
Vomiting
How is hepatitis E transmitted?
Faecal-oral route
Significant zoonotic spread (Pigs)
What is the incubation time for hepatitis E?
15-60 days
What are the 4 serotypes of hepatitis E and where are they found?
Type I and II are found most in Asia
Type III and IV are found most in Europe
How is hepatitis E diagnosed?
HEV IgM
Which forms of hepatitis virus cause acute infection?
A
B
E
Which forms of hepatitis virus cause chronic infection?
B
C
What are some symptoms of acute viral hepatitis?
Abdominal pain
Nausea
Vomiting
Jaundice
Diarrhoea (Occasionally)
Describe the LFTs of acute viral hepatitis?
Raised ALT and AST (>1000)
Possibly raised bilirubin
Normal ALP
Normal Gamma-GT
When will chronic hepatitis infection cause symptoms?
If it progresses to decompensated cirrhosis
What are some symptoms suggestive of chronic hepatitis infection?
Jaundice
Ascites
Encephalopathy
What is primary biliary cholangitis (Cirrhosis)?
This is a genetic condition leading to inflammation of the cholagiocytes lining the biliary tree
What causes primary biliary cholangitis (PBC)?
This is an autoimmune condition in which anti-mitochondrial antibodies target the pyruvate dehydrogenase enzyme of the inner leaflet of the mitochondrial membranes of cholangiocytes
Describe the pathology of primary biliary cholangitis?
Damage to cholangiocytes causes inflammation and granuloma formation, which can cause obstruction, leading to cholestasis, necrosis and fibrosis
Who is most at risk of PBC?
Females (10:1 ratio)
What are some symptoms of PBC?
Fatigue
Itch without rash (Due to bile build up in blood)
Xanthelasma
Xanthoma
RUQ pain or discomfort
How is PBC diagnosed?
Positive AMA test
Cholestatic LFTs
Liver biopsy
How is PBC treated?
Treatment is mostly to prevent symptoms such as itching, with urseodeoxycholic acid or obeticholic acid
Liver transpantation can be performed
How many types of autoimmune hepatitis are there?
2
What is the age distribution for Type I autoimmune hepatitis?
Bimodal age distribution
Ages 15-25
ges 45-70
What gender is most at risk of autoimmune hepatitis?
Females (3.6:1 ratio)
What are some conditions associated with Type I autoimmune hepatitis?
Autoimmune thyroiditis
Grave’s disease
Pernicious anaemia
Systemic sclerosis
What antibodies are the cause of type I autoimmune hepatitis?
ANA - Anti-Nuclear Antibodies
ASMA - Anti-Smooth Muscle Antibodies
What antibodies are the cause of type II autoimmune hepatitis?
LKM-1 - Liver Kidney Microsomal
AMA - Anti-Mitochonrial Antibodies
What age is most at risk of type II autoimmune hepatitis?
Children and young adults
What are some common mutations that can lead to autoimmune hepatitis?
HLA mutations
IgG mutations
T-cell receptor mutations
What are some drugs that can trigger autoimmune hepatitis?
Oxyphenistan
Methyldopa
Nitrofurantoin
Diclofenac
Minocycline
Statins
What are some symptoms of autoimmune hepatitis?
Malaise
Fatigue
Nausea
Abdominal pain
Anorexia
Jaundice
What are some clinical signs of autoimmune hepatitis?
Hepatomegaly
Jaundice
Splenomegaly
How will autoimmune hepatitis affect LFTs?
Elevated AST and ALT (100-800)
Elevated prothrombin time
Antibodies
What tests are used in diagnosis of autoimmune hepatitis?
LFTs
Liver biopsy
What is the treatment regime used in autoimmune hepatitis?
Prednisolone (30mg to 15mg at week 4 then 10mg daily)
Azathioprine (50-100mg)
What are some common drugs that can cause chronic drug induced hepatitis?
Antibiotics (Co-amoxiclav, flucloxicillin)
NSAIDs
Paracetamol
Methotrexate