Liver Conditions Flashcards
What duration defines chronic liver disease?
Disease greater than 6 months
What is the clinical pathway of cirrhosis?
1) Causes of chronic liver disease - presents as signs and symptoms of the causal disease
2) Recurrent inflammation and process of fibrosis
3) Compensated cirrhosis - presents with stigmata of cirrhosis
4) Decompensated cirrhosis leading to chronic liver failure or acute-on-chronic liver disease
What are the 4 cells of the liver?
Hepatocytes, Endothelial cells, Kupffer cells and Hepatic stellate cells
What is the function of hepatic stellate cells?
Storage of vitamin A as retinol
What is the function of Endothelial cells in the liver?
Regulate the passage of molecules from the blood to the liver
What is the function of Kupffer cells?
Liver’s own immune system
What is liver fibrosis?
The accumulation of tough, fibrous scar tissue in the liver as a result of injury healing process going wrong
What is the pathophysiology of progression of fibrosis to cirrhosis?
1) Hepatocytes are injured due to infection with a virus, heavy alcohol consumption, toxins, trauma etc, and activates the immune system.
2) Hepatocyte injury stimulates inflammatory immune cells to release cytokines, growth factors etc which direct hepatic stellate cells (source of most ECM) to activate and produce collagen type I and III, glycoproteins, proteoglycans, and other substances
3) These substances are deposited in the hepatic parenchyma and space of disse of the liver, the latter causing capillarisation - where capillaries lose fenestration which blocks exchange (portal hypertension)
4) At the same time, the process of breaking down or degrading collagen is impaired so regeneration is limited to small nodules
What is Chronic Liver Disease, and what is it not?
Chronic liver disease is a disease process resulting in cirrhosis – not a disease in itself
How long does it normally take to get from a healthy liver to chronic liver disease?
20 years
What are the main causes of cirrhosis?
Common: - Alcohol - NAFLD - Hep C/B - PBC/PSC - Autoimmune hep Less common: -Haemachromotosis - Wilson’s -alpha 1 antitrypsin
What actually is cirrhosis?
Pathological end-stage of any chronic liver disease. Irreversible liver damage with loss of normal liver architecture histologically with bridging fibrosis and nodular regeneration
What is steatosis?
Infiltration of liver cells with fat, associated with disturbance of the metabolism by, for example, alcoholism, malnutrition, pregnancy, or drug therapy.
What is the most common cause of chronic liver disease in the western world?
NAFLD
What is the 2 Hit Paradigm for the pathophysiology of NAFLD?
First hit: Most likely insulin resistance leading to accumulation of triglycerides in the liver and hepatic steatosis development Second hit: additional oxidative injury required to manifest the nectro-inflammatory component
True or False: NAFLD and metabolic syndrome aren’t associated
False, nice try
What is the relationship between NASH and NAFLD?
NAFLD is an umbrella term which encompasses simple steatosis (fatty liver) without liver inflammation, and Non-alcohol steatohepatitis (NASH) where there is inflammation as a result of fatty infiltration with risk of fibrosis and cirrhosis
How would you differentiate between simple steatosis and NASH?
US and Liver biopsy
Which conditions does auto-immune liver disease cover?
• Primary Biliary Cholangitis (Cirrhosis) • Auto-immune Hepatitis • Primary Sclerosing Cholangitis
What is Primary Biliary Cholangitis?
Chronic autoimmune disease where the epithelial cells of the small intrahepatic bile ducts are damaged by the immune system. Characterised by progressive bile duct damage (and eventual fibrosis/loss)
What is the underlying aetiology of PBC?
There is a very high incidence of autoantibodies, most characteristically directed against mitochondrial antigens (antimitochondrial antibody).
What is the pathophysiology of PBC?
Process in PBC is damage to, and progressive destruction of, the biliary epithelial cells lining the small intrahepatic bile ducts. Bile ducts are damaged in the context of portal tract inflammation, further supporting the concept of an autoimmune component to the disease. Loss of bile duct cross-sectional area within the liver leads to cholestasis with progressive bile acid retention. Bile acid pooling can cause secondary damage within the liver, further contributing to progressive bile duct loss
Which is more common in women: PBC or PSC?
PBC (B for burds)
What are the symptoms of PBC?
Asymptomatic initially, then fatigue, itch without rash, xanthesalma and xanthomas
How would you diagnose PBC?
• Positive AMA (anti-mitochondrial antibody) • Cholestatic liver function tests (LFTs) • Liver Biopsy
What is the treatment for PBC?
Urseo deoxycholic acid (UDCA)
What is the beneficial effects of UDCA on PBC?
1) it increases the rate of bile flow from the hepatocytes, thereby combating cholestasis and diluting toxic bile acids in bile. 2) it inhibits the body’s production of toxic bile acids, thereby preventing further injury to the hepatocytes. 3) it inhibits apoptosis of the hepatocytes 4) it mildly inhibits the immune response in the liver, thereby possibly reducing immunological injury to the bile ducts and liver.
What is auto-immune hepatitis characterised by?
Characterised by the presence of circulating auto-antibodies with a high serum globulin concentration and inflammatory changes on liver histology,
Who is affected by autoimmune hepatitis more, men or women?
Women (of course)
Who is affected by Type 1 and Type 2 auto-immune hepatitis?
Type 1 - adults
Type 2 - children and young adults
Which antibodies characterised Type 1 auto-immune hepatitis?
• ANA (anti-nuclear antibodies) • ASMA • SLA severity • IgG • AMA • pANCA
Which antibodies characterised Type 2 auto-immune hepatitis?
Just LKM -1 and AMA
How does auto-immune hepatitis present?
- Hepatomegaly - Jaundice - Stigmata of chronic liver disease - Splenomegaly - Elevated AST and ALT - Elevated PT - Non-specific symptoms: malaise, fatigue, lethargy, nausea, abdominal pain, anorexia
How is autoimmune hepatitis diagnosed?
- Elevated AST and ALT - Elevated IgG - Rule out other causes - Presence of autoimmune antibodies - Liver biopsy
What is the hallmark histological finding of autoimmune hepatitis?
Interface hepatitis, neutrophils everywhere
What is the treatment for auto-immune hepatitis?
Prednisolone and Azathioprine (steroids and immunosuppressants)
What is cholestasis?
When bile can’t flow from the liver to the duodenum
What is Primary Sclerosing Cholangitis?
Cholestatic autoimmune liver disease causing continued inflammation, fibrosis and strictures of the intra and extra hepatic bile ducts, leading to cirrhosis, and end-stage liver disease.
Which is more common in men: PBC or PSC?
PSC
What is haemochromotosis?
Genetic iron overload syndrome. Specifically: autosomal-recessive disorder leading to dysregulated intestinal absorption of dietary iron and increased iron release from macrophages.
Which genes are associated with haemochromotosis?
C282Y or H63D, mutations in HFE gene on short arm of chromosome 6 (according to Zack anyway..)
What is the treatment for haemochromotosis?
Venesection (regular blood transfusion)
What is Wilson’s disease?
Autosomal-recessive disease of copper accumulation and toxicity caused by a defect in an enzyme involved in the biliary excretion of excess copper. Loss of function of caeruplasmin (copper binding protein).
What is lenticulo-hepatic degeneration in Wilson’s?
Get copper deposition in liver and basal ganglia
How does Wilson’s clinically present?
• Neurological- chorea-atheitoid movements • Hepatic – cirrhosis or sub-fulminant liver failure • Kaiser Fleisher rings
What is the treatment for Wilson’s?
Copper chelation drugs
What is Alpha 1 Anti-trypsin Deficiency?
Mutation in the A1AT gene causing deficient of aloha 1 anti-trypsin
What does alpha 1 anti-trypsin normally do?
Breaks down proteases to stop them breaking down proteins of membranes
What are the clinical pathologies of Alpha 1 Anti-trypsin Deficiency?
• Lung emphysema (as the proteins of membranes are broken down) • Liver deposition of mutant protein, cell damage
What is the management for Alpha 1 Anti-trypsin Deficiency?
Supportive
What is Budd Chiari Syndrome?
Hepatic venous outflow obstruction at any level from the small hepatic veins to the inferior vena cava and the right atrium, regardless of the cause of the obstruction. (blockage of drainage of liver)
Hows does Budd Chiari present?
• Acute: Jaundice and tender hepatomegaly • Chronic- Ascites
How would you diagnose Budd Chiari?
US visualisation of hepatic veins
How would you treat Budd Chiari?
Recanalization or TIPS
What is a TIPS procedure?
Transjugular intrahepatic portosystemic shunt - An artificial channel within the liver that establishes communication between the inflow portal vein and the outflow hepatic vein. Mostly used in portal hypertension and Budd chair
What is methotrexate and which implications can it have for the liver?
Drug used for rheumatoid arthritis and psoriasis. Can be toxic to the liver causing fibrosis
What is cardiac cirrhosis?
Cirrhosis secondary to high right heart pressures
What is Acute Liver Disease?
Rapid development of hepatic dysfunction without prior liver disease. Due to any insult to the liver causing damage
What is acute hepatic encephalopathy?
Occurs when the liver stops being able to filter blood so get neurological effects, confusion and a flap
What is the limit to the proportion of hepatocytes which can die and the liver will still regenerate?
90%
What are the clinical features of acute liver disease?
- None (common) - Jaundice - Lethagy - Nausea - Anorexia - Itch - Abnormal LFTs
With acute liver disease, what does high ALTs make you think of?
Paracetamol
What are some of the main causes of acute liver disease?
Viral A-E, Ebstein-barr, drugs, shock liver (suddenly hypotensive), cholagnitis, alcohol, malignancy, chronic liver disease, budd chiari
What is the management of acute liver disease?
- Rest with fluids and no booze - Increase calories (but not high fat) - sodium bicarbonate bath, for itch
What is Fulminant Hepatic Failure?
Sub-group of acute liver disease. A clinical syndrome resulting in massive necrosis of liver cells leading to severe impairment of liver function
What are the characteristics of Fulminant Hepatic Failure?
Jaundice and encephalopathy in a patient with a previously normal liver
What is the treatment for Fulminant Hepatic Failure?
- Supportive
- Inotropes & Fluids
- Renal replacement
- Management of raised ICP
- Transplant
What should the liver look like normally?
light, tan in colour with a smooth surface
What is the main rule of pathogenesis of almost any liver disease?
Any insult causes death of hepatocytes, which causes inflammation results in activation of fibroblasts which causes scarring. This recurring results in cirrhosis
Which two ways can jaundice be classified?
By site (pre-hepatic ec) and by type of bilirubin (conjugated vs. unconjugated)
What is the underlying cause of pre-hepatic jaundice?
Too much haem to break down e.g. haemolytic anaemia
What is the underlying cause of hepatic jaundice?
Liver cells injured or dead e.g. acute liver failure, alcoholic hepatitis, decompensated cirrhosis
What is the underlying cause of post-hepatic jaundice?
Bile cannot escape into the bowel e.g. gallstones, tumours of head of pancreas
What is cirrhosis?
A special type of fibrosis that occurs as an end-point as a result of repeated insult
What are the 3 main complications of cirrhosis?
Portal hypertension, ascites and liver failure
What are the 3 main sites of portal-systemic anastomoses?
Oesophageal varices, caput medusa and haemorrhoids
How is alcohol normally metabolised in the liver?
By 2 main pathways: alcohol dehydrogenase and cytochrome P-450 2E1. Alcohol is metabolised to acetaldehyde by alcohol dehydrogenase, which then is metabolised to acetate by the mitochondrial enzyme acetaldehyde dehydrogenase. Alcohol dehydrogenase and acetaldehyde dehydrogenase reduce nicotinamide adenine dinucleotide (NAD) to NADH (reduced form of NAD).
How can excess alcohol then cause damage to the liver, considering alcohol metabolism?
Excessive NADH in relation to NAD inhibits gluconeogenesis and increases fatty acid oxidation, which in turn promotes fatty infiltration in the liver. Results in an inflammatory response and fibroblast activation