Alcoholic Liver Disease Flashcards
How does Ethanol metabolism effect NADH/NAD ratio
Increases it
How does increased ethanol metabolism effect fatty acid synthesis in the liver
Increases it
How does ethanol effect fatty acid oxidation in the liver
Decreases it
What is the consequence of increased fatty acid synthesis and decreased oxidation
Hepatic accumulation of fatty acids which are esterified to glyceries
How does changed in oxidation-reduction effect carbs and protein metabolism
Impairs them - causes centrilobular necrosis od the hepatic acinus (typical of alcohol damage)
What do kupffer cells release in reaction to ethanol accumulation
TNF-alpha
Result of TNF-alpha release
Release of ROS leading to tissue injury and fibrosis
How is acetaldehyde formed
By the oxidation of ethanol and its effect on hepatic proteins could be a factor in producing liver cell damage
How does alcohol effect drugs
Enhance the effects of their toxic metabolites
Main causes of alcoholic liver disease
- Abuse
- Genetic predisposition
- Immunological mechanisms
How does fatty liver occur
- Metabolism of alcohol produces fat in liver
- No liver cell DAMAGE
- Sometimes, collagen lays down around central hepatic veins + this can progress to cirrhosis without a preceding hepatitis
How does alcohol effect stellate cells
Transforms them to myofibroblastic cells
Can fat disspear on stopping alcohol
Yes
How does alcoholic hepatitis occur
Infiltration of polymorphonuclear leucocytes and hepatocyte necrosis
Features of alcoholic hepatitis
Dense cytoplasmic inclusions - Mallory bodies
Giant mitochondria
Characteristics of alcoholic cirrhosis
- Micronodular Types
- Fatty change seen
- Evidence of pre-existing alcoholic hepatitis
Clinical presentation of Fatty Liver
- Asymptomatic
- Vague abdominal symptoms of nausea, vomiting, diarrhoea
- Hepatomegaly
Clinical presentation of alcoholic hepatitis
- Mild jaundice
- Signs of chronic liver disease (ascites, bruising, clubbing)
- Abdominal pain with high fever
- Deep jaundice
- ankle oedema
Diagnosis of fatty liver
- ELEVATED MCV
- RAISED Alt and AST
- Ultrasound demonstrates fatty infiltration as well as liver histology
Diagnosis of alcoholic hepatitis
- Leucocytosis
What would blood tests show in alcoholic hepatitis
Serum bilirubin
Serum AST and Alt
Serum alkalin phosphate
PTT
How to treat alcoholic liver disease
- STOP DRINKING
How to treat withdrawal symptoms from not taking alcohol
Diazepam
How do we prevent Wernicke-Korsakoff encephalopathy associated with alcoholic liver disease
IV THIAMINE
What is Wernicke-Korsakoff encephalopathy
Presents with ataxia
Confusion
Nystagmus
When do people suffer from Wernicke-Korsakoff
During withdrawal
When does Wernicke-Korsakoff occur
6-24 hours after last drink (lasts up to a week)
How do we alter diet for those with alcoholic liver disease
High in vitamins and proteins
Ho wis fatty liver disease treated
Stopping alcohol
How is alcoholic hepatitis treated
- Nutrition maintained by enteral feeding + supplements
- Steroids
- Infections should be treated
- Stop drinking alcohol for life
How are infections in alcoholic hepatitis treated
anti-fungal prophylaxis
How is alcoholic cirrhosis treated
Reduce salt intake
Stop drinking for life
Avoid aspirin and NSAIDS
Liver transplant
When should drugs be considered as a cause of live injury
When abnormal liver biochemical tests are found
What four ways can drugs cause liver damage
- Disruption of intracellular Ca homeostasis
- Disruption of bile canalicular transport mechanisms
- Induction of apoptosis
- Inhibition of mitochondrial function
How is inhibiting mitochondria function dangerous
Prevents fatty acid metabolism and accumulation of both lactate and reaction oxygen species
What is the most common cause of acute liver failure in the USA
Drug hepatotoxicity
When do most drug reactions occur
Within 3 months of starting the drug
‘not so much what drug bu what drug you started recently’
When is onset of drug hepatotoxicity seen
1-12 weeks of starting
Main causes of drug haeptotoxicity
- Antibiotics (Augmentin, Flucloxacillin, TB drugs and Erythromycin)
- CNS
- Immunosuppressants
- Analgesics
- GI Drugs
Name two CNS drugs that can induce liver damage
Chlorpromazine
Carbamazepine
Name an analgesic that causes liver injury
DICLOFENAC
What drugs do not induce liver injury
- ASPIRIN
- NSAIDS (except diclofenac)
- Beta0blockers
- ACE
- Thiazides
- Calcium channel blockers
How is drug-induced liver injury treated
Stops within 3 months of stopping the drug
How is paracetamol metabolised
Phase II reaction: conjugated with glucuronic acid or sulphate
What happens to paracetamol if glucuronic acid and sulphate stores are low
Phase I metabolism via oxidation to produce NAPQI then conjugated with glutathione and excreted
How does paracetamol poisoning occur
Liver GLUTATHIONE becomes depleted eventually so NAPQI can’t be conjugated
Clinical features of paracetamol hepatotoxicity
- ANorexia
- Nausea
- Vomiting
- Upper right quadrant pain
- Jaundice and encephalopathy due to liver damager
Is paracetamol-induced liver injury detectable on liver biochemistry
Not until 18 hours after ingestion
How long do patients initially remain asymptomatic for following overdose on paracetamol
24 hours
When does liver damage reach its peak
Raised ALT
PTT
72-96 hours after ingestion
What is encephalopathy
impaired functioning of the brain
What happens if paracetamol induced liver injury is not treated
Hepatic failure (fulminant)
Why is there acute kidney injury from paracetamol-induced liver injury
Acute tubular necrosis
Blood tests for paracetamol-induced liver damage
- Metabolic acidosis
- Hypoglycaemia (overdose inhibits glucose production)
- Prolonged PTT
- Raised creatinine
How is paracetamol-induced liver damage treated
Gastric decontamination
Replenish cellular glutathione stores
Treat rash
How is gastric decontamination treated
ACTIVATED CHARCOAL
How do we replenish cellular glutathione stores
IV N-ACETYLCYSTEINE
How is rash treated
CHLORPHENAMINE
Where is aspirin metabolised
Liver
How is aspirin metabolised
To salicylic acid by esterase’s -> salicylic acid and sailcyl phenolic glururonide
What happens in an overdose
Metabolic pathway is oversaturated so kidneys compensated by increasing renal excretion of aspirin (PATHWAY IS EXTREMELY SENSITIVE to urinary pH)
How does overdose of aspirin effect respiratory centre
Stimulates it, increasing depth and rate of respiration = repisratoy alkalosis as you excrete more acidic CO2
Compensatory mechanisms for respiratory alkalis
Renal excretion of bicarbonate and potassium = metabolic acidosis
What processes does aspirin interfere with
Carbs, fat and protein metabolism
Disrupt oxidative phosphorylation
Increased conc. of lactates, pyruvate and ketones (metabolic acidosis)
Clinical features of aspiring poisoning
- Patients with respiratory alkalosis due to stimulation of salicylic acid on the central respiratory centre and develop metabolic acidosis to compensate
- Hyper- or hypoglycaemia
- HYPERVENTILATION and TACHYPNOEA (this causes respiratory alkalosis)
- Sweating, vomiting, dehydration, epigastric pain, tinnitus and deafness
- Rarely in severe poisoning there may be coma and convulsion
Treatment of aspirin
- Fluid + electrolyte replacement with special attention (mild cases)
- Urine alkalisation (enhance renal elimination of aspirin)
- Haemodialysis (treatment of choice for poisoned patients)
How is metabolic acidosis with apisirn poisoning treated
IV NA BICARBONATE
What is Hereditary HAEMOCHROMATOSIS
Inherited disorder of iron metabolism where there is increased intestinal iron absorption leads to iron deposition in joints, liver, heart, pancreas, adrenals and skin
What does hereditary haemochromatosis lead to
Fibrosis and functional organ failure
What people does this disorder commonly effect
Caucasians Male
Why is hereditary haemochromatosis not common in females
Since menstrual blood loss is protective
Main cause of hereditary haemochromatosis
HFE gene mutation on chromosome 6 - AUTOSOMA RECESSIVE
High intake of iron and chelating agents
Alcoholics
Is autosomal dominant mutation common
No
Risk factors for hereditary haemochromatosis
Family history
Alcoholic
Pathophysiology for hereditary haemochromatosis
- HFE gene protein interacts with transferrin R1
- Hepcidin is increases in iron deficiency states and decreases in iron overload
- Expression of hepcidin is decreased in hereditary haemochromatosis and causes iron overload
- Excess iron is taken up by the liver
- Fibrosis
- Iron content is increased in th liver and pancreas
- Cirrhosis
What age group is hereditary haemochromatosis common in
50s
Early onset of hereditary haemochromatosis
Tiredness and arthralgia
How does hereditary haemochromatosis effect endocrine function
Hypogonadism (less testosterone and oestrogen)
Pituitary dysfunction
Late sunsets of hereditary haemochromatosis
Slate-grey pigmentation Chronic liver disease Hepatomegaly Cirrhosis Dilates Cardiomyopathy Osteoporosis Cardiac Manifestations (e.g. heart failure, arrhythmias)
Symptoms in hereditary haemochromatosis due to iron overload
- Bronze skin pigmentation
- Hepatomegaly
- Diabetes mellitus
How is hereditary haemochromatosis diagnosed (homozygotes)
- Raised resume iron
- Raised scrim ferritin
- Normal liver biochemistry
hereditary haemochromatosis diagnosed (heterozygotes)
- Normal biochemical tests
2. Raised serum iron transferring saturation or serum ferritin
How is MRI good in hereditary haemochromatosis
Shows iron overload
How does a liver biopsy help in hereditary haemochromatosis
Extent of tissue damage
How does ECHO and ECG help in hereditary haemochromatosis
Cardiomyopathy suspected
How is hereditary haemochromatosis treated
Venesection Treat Diabetes 3. Testosterone replacement 4. Diet low in iron 5. Avoid druit/fruit juice 6. Screening all first-degree relatives
Benefits of venesection
Prolongs life and reverses tissue damage
How often do we do venesection
3-4 times a year
How is hereditary haemochromatosis managed
Monitor serum iron and ferritin during venesection
What is done when patients can’t tolerate venesection
DESFERRIOXAMINE is given (Chelation therapy - preventing absorption of iron by forming bonds with a single metal ion)
What is Wilson’s Disease
Inherited disorder where too much copper is in the liver (not enough excretion) and CNS
What kind of genetic inheritance is wilson’s disease
AUTOSOMAL RECESSIVE on chromosome 13 resulting in a molecular defect within a copper-transporting ATPase
In which population is Wilson’s disease common
Countries where marrying first degree relatives is common
Where is dietary copper commonly absorbed
Stomach
Small upper intestines
Where is copper transported to
Liver bound to albumin
What happens to copper in liver
Incorporated into Caeruloplasmin and secreted into the blood
Is Liver histology for Wilson’s disease diagnostic
No
Appearance of inner body in Wilson’s disease
Basal ganglia are damaged and show cavitation, kidney shows tubular degeneration
Erosions seen in bone
Clinical presentation of Wilson’s disease
- Hepatitis/Cirrhosis/Fulminant liver failure
- Young adults have CNS problems (dementia, tremors, dysphagia)
- educed memory
4, Liver disease (acute hepatitis to chronic to cirrhosis) - Kayser-Fleischer ring
What is Kayser-Fleischer ring caused by
Copper deposition in corners results in greenish-brown pigments at the corneoscleral junction
Blood tests in Wilson’s disease
- Serum copper and caeruloplasmin are reduced
What does liver biopsy show in wilson’s disease
Increased hepatic copper, hepatitis and cirrhosis
Haemolysis and anaemia
What will an MRI show for Wilson’s disease
Basal ganglia and cerebella degeneration
How is Wilson’s Disease treated
- Avoid foods high in copper
2. Lifelong chelating agent (PENICILLAMINE)
Side-effects of using lifelong chelating agents
- Skin rashes
- Fall in WBC
- Haematuria
- Renal Damage
Symptoms of alcoholic hepatitis
- Fatigue
- Ascites
- Jaundice
- Hepatic encephalopathy (Wernicke-Korsakoff syndrome)
- Delirium tremens
What is delirium tremens
SHAKING
Irregular heart rate
Sweating
Hallucination
Histopathology seen in alcoholic hepatitis
- Mallory’s hyaline body
- Hepatocytes swell up with excess fat, water and protein
- Inflammation due to neutrophilic invasion (necrotic changes causes this)
- MEGAMITOCHONDRIA
What causes Wernicke’s encephalopathy
- Thiamine deficiency
- Poor diet
- Poor intake of vitamins
- Gastritis
How is Wernicke’s encephalopathy treated
- PABRINEX + Vit B/Thiamine
How is alcoholic withdrawal relapse prevented
- ACAMPROSATE
- DISULFIRAM
- NALMEFINE
Pharmacology of DISULFIRAM
- directs oxidative metabolism of alcohol:
Causes build up of acetaldehyde
Side-Effects of DISULIFRAM
- Flushing of skin
- Tachycardia
- SOB
- Nausea
- VOmiting
What is NALMEFINE
- Opioid receptor antagonist
- Modifies activity at receptor sites linked to reward centres (acts on dopamine)
- Reduced feeling of reward