Liver and Biliary Tract Pathology Flashcards
what is cirrhosis of the liver?
scarring of the liver after long term damage
what are the 4 main consequences of liver cirrhosis?
reduced metabolic capacity
portal hypertension
ascites
shunting of blood by-passing liver
why in liver cirrhosis does ascites occur mainly in the abdomen?
because of the low albumin and very higher pressure from portal system
(large hydrostatic pressure of capillaries [Pc], low osmatic drive of capillaries [pieC])
what are the 4 main causes of liver damage?
obesity/diabetes
alcohol
viruses
drugs
what happens to the size of the liver in cirrhosis?
becomes small shrunken and hard
what is ‘caput medusae’?
when the umbilical vein (ligamentum hepes) becomes back in use because of portal hypertension
what is the function of up-regulating of the umbilical vein?
to help with the diversion of blood from portal system to systemic system (shunting) in order to combat the high portal pressure
what happens to highly metabolised drugs when there is portal-systemic shunting?
increased plasma levels
why is there increased plasma levels of some drugs due to portal-systemic shunting?
due to lack of first pass metabolism
what is meant by saturable kinetics of drugs?
metabolism increases until a certain point where it then remains at a constant rate- because liver has become saturated
why in liver cirrhosis is the renin-angiotensin-aldosterone system up regulated?
because low albumin causes low plasma volume which activates renin production from the kidneys
what can this up-regulation of the RAAS system cause in a patient with a cirrhotic liver?
secondary aldosteronism (liver is unable to break the aldosterone down anymore)
why do both endothelin and oestrogen concentrations of the plasma increase in patients with cirrhotic livers?
because the liver become unable to metabolise endothelin and oestrogen leading to their accumulation
what does the increased oestrogen due to liver cirrhosis cause to males?
gynaecomastia
feminisation of men and loss of secondary sexual characteristics
what are the 3 main consequences of cirrhotic liver in respect to the kidneys?
water retention
sodium retention
potassium loss
what is produced in response to hormone vasoconstrictors (such as endothelin, aldosterone, angiotensin II) that acts to maintain kidney function?
renal vasodilator prostaglandins
why should NSAIDs be avoided if possible in patients in dehydrated states (such as alcoholism/cirrhotic livers)?
NSAIDs inhibit vasodilator prostaglandins so will worsen kidney impairment due to vasoconstriction
(due to the high concentration of vasoconstrictors produced because of the dehydration)
if you are prescribing a NSAID for a patient with cirrhotic liver what must be co-prescibred?
a proton pump inhibitor
what 2 phases occur in drug metabolism in the liver?
phase 1: biotransformation
phase 2: conjugation
what drug metabolism phase is affected early in liver disease and what phase is affected late in liver disease?
phase 1 affected early
phase 2 affected late
what is the highly reactive intermediate that knackers your liver and is formed from the metabolism of paracetamol?
N-acetyl-p-benzoquinonimine
why are healthy patients unaffected by n-acetyl-p-benzoquinonimine?
(at advised doses of paracetmol)
n-acetyl-p-benzoquinonimine is removed quikly with glutathione
what happens if the glutathione runs out and herefore not all the n-acetyl-p-benzoquinomine can be removed?
paracetamol overdose
-can lead to fulminant hepatitis
why does being drunk reduce risk of overdosing when taking too many paracetamol tablets?
alcohol has used up all the enzyme paracetamol needs for metabolism, so paracetamol isn’t metabolised as quickly and acetyl-p-benzoquinomine is formed at a much slower rate
why does being a long term alcoholic increase risk of overdosing when taking too many paracetamol tablets?
(if not currently drunk)
as a long term alcoholic your body has more receptors and so the paracetamol will be metabolised much quicker and acetyl-p-benzoquinomine is formed at a much faster rate
why does liver failure increase risk of overdosing when taking normal doses of paracetamol?
liver failure reduces glutathione stores, so even though paracetamol is being metabolised at a normal rate, there isn’t enough glutathione to remove the acetyl-p-benzoquinomine
what is Hy’s Rule?
if ALT/AST > 5x Upper Limit Normal
and
Bilirubin > 3mg/dl
the drug is causing liver disease
which diuretic is best for people with liver cirrhosis to remove excess fluid?
spironolactone
due to potassium-sparing effects
what type of excretion route do you want the drugs you are prescribing to a patient with liver cirrhosis to have?
renal excretion
what is acute liver disease?
rapid development of hepatic dysfunction without prior liver disease
(less than 6 months duration of symptoms)
in acute liver disease how do you get the liver to recover without scarring or ongoing damage?
remove stimulus
what do liver function tests measure?
ALT
AST
Alk Phos
GGT
what do true liver function tests measure?
bilirubin
albumin
prothrombin time
what happens to prothrombin time if there is liver disease?
increases
what does acute liver failure do on top of acute liver disease?
causes encephalopathy and prolonged coagulation
what must be abnormal for acute liver disease?
LFTs
where is pain most likely to be felt in acute liver disease?
right upper quadrant
what are the 8 clinical features you might expect with acute liver disease?
none jaundice lethargy nausea anorexia pain itch arthralgia (although usually more chronic)
what are the 7 main causes of acute liver disease?
viral drugs shock liver cholangitis alcohol malignancy chronic liver disease
what are the most common viral causes of hepatitis?
hep A hep B hep C hep D hep E cytomegalovirus epstein-barr virus toxoplasmosis
what drug is an important cause of acute liver disease?
paracetamol
how are hep B and C passed?
blood and some body fluids
-mainly sex and passed through needles
how are hep A and E passed?
faecal-oral route
when can hep D cause infection?
only hepatitis B is also present
what is shock liver caused by?
sudden hypoperfusion leading to massive hepatocyte necrosis
what is Budd Chairi?
a rare cause of acute liver disease caused by obstruction of hepatic veins
who does Budd Chairi typically present in?
young women starting oral contraceptives
what are 2 rare causes of acute liver disease that are disease of pregnancy?
acute fatty liver of pregnancy
cholestatsis of pregnancy
what are the 4 main factors for liver disease?
direct toxicity
nutrition
immunological
genetic predisposition
what is haemochromatosis?
a genetic condition where iron levels accumulate in the body
patient absorbs more iron from their food than they should
what is non-alcoholic steatoic hepatitis caused by?
usually due to unhealthy lifestyle (high in fats) causing ongoing inflammation in the liver
what is the treatment of acute liver disease?
- rest (usually up to 3 months, may be 6)
- fluids
- no alcohol
- increase calories (but high fat food poorly tolerated)
- sodium bicarbonate bath, cholestryamine or uresodeoxycholic acid- for itch
why is hyoglycaemia a very serious clinical sign of acute liver disease?
because the liver usually makes glucose until the very end
what is fulminant hepatic failure?
jaundice and encephalopathy in a patient with previous normal liver
out of the hepatitis viruses which is the most likely to cause fulminant hepatic failure?
hepatitis B
what is the treatment of fulminant hepatic failure?
supportive inotropes and fluids renal replacement management of raised ICP possible transplantation
what is the main clinical manifestation of hepatitis viruses?
liver disease
how long does it take for patients with hep A to recover and rid their body of the virus?
usually within 3 months
how can all viral hepatitis infection be confirmed?
blood serology
which hepatitis’ have a vaccine?
hep A
hep B
when is chronic infection of hep B most likely to result?
if first exposure is in childhood
what 4 groups of people have a higher than average risk of hep B in the UK?
- people born in areas of intermediate/high prevalence
- people with multiple sexual partners
- people who inject drugs
- children of infected mothers
what antigen is present in the blood of all individuals infected with Hep B?
HBsAg
if HBsAg is in the blood of an individual for over 6 months what does this mean?
chronic Hep B infection
what 2 makers indicate an individual with hep B is highly infectious?
HBeAg (usually)
high titre of HBV DNA
when does a patient have anti-HBs?
if a patient is immune to hep B- natural infection or vaccination
what marker does a patient who gained immunity through natural infection to hep B have that a patient who gained immunity through vaccination doesnt?
anti-HBc
as well as the anti-HBs that vaccination also gives
what marker of Hep B is best at giving an indicator of prognosis?
HBV DNA
why do individuals with hep B need to be monitored regularly even if at first their viral load is very low?
relationship with infection is dynamic and so later on in disease progression they might have a very high HBV DNA load
what can be given a post-exposure prophylaxis for an individual who has come into contact with another individual with Hep B?
vaccine + HBIG
HBIG = hyperimmune Hep B immunoglobulin
which is more easily transmitted by sex- hep B or C?
hep B
if patient has antibody to hep C virus what does this mean?
past or active infection
if a patient has hep C RNA what does this mean?
active infection
compare the nucleic acid present in hep B compared to hep C?
hep B= DNA
hep C= RNA
once a patient with hep B has chronic infection can they have a spontaneous cure?
yes
once a patient with hep C has chronic infection can they have a spontaneous cure?
no
what is the progression of disease from chronic hepatitis?
chronic hepatitis
cirrhosis
hepatocellular carcinoma or chrnoic liver failure
death
compare the chances of hep B and hep C becoming a chronic infection?
hep C is more likely to become chronic than resolve
hep B is more likely to resolve than become chronic (unless child is infected at birth)
if child is infected at birth with hep B what is the likely progression?
likely to become chronic rather than resolve
what is the management of acute viral hepatitis?
- supportive
- no antivirals given
- monitor for encephalopathy
- monitor for resolution
- notify public health
- immunisation of contacts
- test for other infections if at risk
- vaccinate against other infections if at risk
what is the management of chronic viral hepatitis?
- antivirals
- vaccination of other infections
- infection control
- reduced alcohol intake
- hepatocellular carcinoma awareness/screening
compare the number of antivirals on the market for hep C compared to hep B?
hep B= 6 antivirals
hep C= 8 antivirals
what is a complete contraindication to the treatment of chronic hepatitis with antivirals?
hepatocellularcarcinoma
as HBV DNA load at initial infection increases what happens to the risk of hepatocellular carcinoma if infection becomes chronic?
greater risk of cancer
for chronic hepatitis, how is alpha interferon administered?
peginterferon injections
what are the common side effects of peginterferon?
flu-like symptoms
what are the less common, but more severe side effects of peginterferon?
thyroid disease
autoimmunde disease
psychiatric disease
what are the side effects of older HCV antivirals such as ribavirin, telaprevir and boceprevir?
anaemia
telaprevir and boceprevircan also cause a sever rash
what are the 2 options for chronic hep B therapy?
- peginterferon alone
2. suppressive antiviral drugs
what are the advantages of peginterferon treatment of chronic hep B?
sustained cure possible from a few months of therapy
what are the disadvantages of peginterferon treatment of chronic hep B?
only minority gain benefit
side effects
injections
what are the advantages of suppressive antiviral drug therapy for chronic hep B?
safer than peginterferone therapy
what are the diseadvantages of suppressive antiviral drug therapy for chronic hep B?
suppression not cure
resistance can develop
what are the 3 virological aims in terms of chronic hep B therapy?
- reduction in HBV DNA (suppression)
- loss of HBeAg (further suppression)
- loss of HBsAg (cure)
what are the 6 main aims of chronic hep B therapy?
- virological aims
- improved liver biochem
- improved histopathology
- reduced infectivity
- reduced progression to cirrhosis and primary hepatocellular carcinoma
- reduced mortality
what is a hepatitic C therapy response defined as?
SVR: sustained virological response (cure as relapse is rare)
what defines sustained virological response?
loss of HCV RNA in blood sustained to 6 months after end of therapy
even if patients have sustained virological response what must be continued if the patient already has cirrhosis?
6 monthly ultrasound screening for hepatocellular carcinoma
even though risk has been reduced, because the liver is cirrhotic patient still has significant risk