Gastroenterology - Hepatology Flashcards
List the functions of the liver.
Metabolic function:
- stores glycogen
- releases glucose
- absorbs fats, fat soluble vitamins (A, D, E, K) and iron
- cholesterol synthesis
Stores bile salts:
- dissolves dietary fats
Conjugates billirubin:
- breakdown product of haemoglobin
Synthesises most clotting factors
Detoxification:
- drug excretion / activation (CYP 450)
- alcohol breakdown
Immune function:
- Kupfer cells engulf antigens
Manufactures proteins:
- albumin
- binding proteins
What are the risk factors for liver disease?
- blood transfusion (esp. before 1990)
- IVDU
- sexual exposure
- medications
- FHx of liver disease, diabetes or IBD
- obesity
- alcohol use
- foreign travel
What are the features of acute liver disase?
- no pre-existing liver disease
- resolves within 6 months
For example:
- hepatitis A
- EBV
- drug induced liver injury
What are the features of chronic liver disease?
- asymptomatic
- persists past 6 months
- may lead to cirrhosis and its complications
For example:
- alcohol use
- hepatitis C
- autoimmune disease
What are some signs of liver disease that could be identified upon examination?
- spider naevae
- clubbing
- palmar erythema
- ascites
How can liver disease be investigated?
- FBC (thrombocytopenia sensitive marker of liver fibrosis)
- ALT (hepatocyte damage)
- ALP (cholestatic damage; concurrent rise in GGT confirms ALP in liver in origin)
- billirubin, albumin and INR are markers of synthetic function
Give some causes of hepatitic liver disease (ALT > 500).
- viral
- ischaemia
- toxins (e.g. paracetamol)
- autoimmune
Give some causes of hepatitic liver disease (ALT 100-200).
- non-alcoholic steatohepatitis
- autoimmune hepatitis
- chronic viral hepatitis
- drug induced liver injury
Give some causes of cholestatic liver disease (dilated ducts).
- gallstones
- malignancy
Give some causes of cholestatic liver disease (non-dilated ducts).
- alcoholic hepatitis
- cirrhosis (e.g. alcohol, PSC, PBC)
- drug induced liver injury (e.g. abx)
What is hepatitis?
Inflammation of the liver, which can range from chronic and low level inflammation, to acute and severe inflammation.
What are the causes of hepatitis?
- alcohol hepatitis
- non-alcoholic fatty liver disease
- viral hepatitis
- autoimmune heptatitis
- drug induced hepatitis (e.g. paracetamol overdose)
Presentation of hepatitis.
- abdominal pain
- fatigue
- pruritis
- myalgia / arthralgia
- n+v
- jaundice
- fever
What are the biochemical findings that are consistent with hepatitis?
Hepatic picture:
- elevated AST / ALT
- proportionally less of a rise in ALP
- hyperbillirubinaemia (conjugated and unconjugated)
What is the most common viral hepatitis worldwide?
Hepatitis A - although fairly rare within the UK.
What type of virus is Hepatitis A?
RNA virus
How is Hepatitis A transmitted?
Faecal-oral route, usually by contaminated food or water.
Presentation of Hepatitis A.
- n+v
- anorexia
- jaundice
Why do patients with hepatitis A commonly have pale stool?
Hepatitis A can cause cholestasis, meaning less stercobillin reaches the rectum causing pale stool.
Urine becomes darker as urobillogen accumulates and is excreted by the renal route.
Treatment of Hepatitis A.
Resolves without treatment within 1-3 months.
Management is usually basic analgesia.
Vaccination is available to reduce the chance of developing infection.
What type of virus is Hepatitis B?
DNA virus
How is Hepatitis B transmissed?
Direct contact with blood or bodily fluids (e.g. sexual intercourse, sharing needles).
Vertical transmission (mother to child through pregnancy and delivery).
What do the following viral markers indicate in hepatitis B?
a) HBsAg
b) HBeAg
c) HBcAb
d) HBsAb
e) HBV DNA
a) surface antigen, suggestive of active infection
b) E antigen, marker of viral replication and suggestive of high infectivity
c) core antibodies, suggestive of past or current infection
d) surface antibody, suggestive of vaccination or past or current infection
e) direct count of the viral load
Which viral markers should be tested for when screening for Hepatitis B?
- HBcAb (previous infection)
- HBsAg (active infection)
Note IgM (acute) and IgG (chronic) versions of HBcAb can indicate whether previous infection was acute or chronic.
If these are positive, do further testing for HBeAg and viral load.
Describe the vaccination programme for Hepatitis B.
Vaccination to Hepatitis B is included as part of the 6 in 1 vaccination for infants.
The vaccine requires 3 doses at different intervals.
Involves injecting the HBsAg - patients tested for HBsAb to confirm their response to vaccine.
What is the management of Hepatitis B?
- prophylactic vaccination
- low threshold for screening
- screen for other blood born viruses
- refer for specialist management
- notify Public Health England
- stop smoking and alcohol
What type of virus is Hepatitis C?
RNA virus
Describe the disease course of Hepatitis C.
- 25% clear the virus independently
- 75% do not clear, and infection becomes chronic
Chronic infection associated with liver cirrhosis and hepatocellular carcinoma.
How is Hepatitis C detected?
Hepatatis C antibody is screening test.
Hepatitis C RNA testing can confirm diagnosis, calculate viral lobe and assess for genotype.
Management of Hepatitis C?
- low threshold for screening
- screen for other blood born viruses
- refer for specialist management
- notify PHE
- stop smoking and alcohol
Medical management using direct acting antivirals (DAA) tailored to specific viral genotype.
What type of virus is Hepatitis D?
RNA virus
Pathophysiology of Hepatitis D.
Only survive in patients with Hepatitis B, as it attaches to the HBsAg to survive.
Hepatitis D increases the risk of complications and disease severity of Hepatitis B, but is very rare in the UK.
What type of virus is Hepatitis E?
RNA virus
How is Hepatitis E transmitted?
Faecal oral route
Presentation of Hepatitis E?
Mild illness, with the virus cleared within a month and no treatment required.
Autoimmune hepatitis causes
a) acute
b) chronic
disease?
a) acute
Describe
a) Type 1 autoimmune hepatitis
b) Type 2 autoimmune hepatitis
a) occurs in adults, typically presenting in post-menopausal women with fatigue and features of liver disease upon examination.
b) occurs in children and young adults, presenting with acute hepatitis and jaundice.
Give the autoantibodies associated with Type 1 autoimmune hepatitis.
- ANA
- anti-actin
- anti-SLA
Give the autoantibodies associated with Type 2 autoimmune hepatitis.
- anti-LKM1
- anti-LC1
How is autoimmune hepatitis treated?
- high dose prednisolone
- azathioprine
- liver transplant in end-stage liver disease*
*Note autoimmune hepatitis can recur in transplanted livers, so is not necessarily curative.
Give the steps of alcoholic liver disease.
Chronic and excessive alcohol consumption leads to:
- Alcohol related fatty liver: drinking leads to a build up of fat in the liver. If drinking stops, this process reverses within around 2 weeks.
- Alcoholic hepatitis: chronic alcohol consumption causes inflammation within the liver. Permanent abstinence may allow reversal of mild alcoholic hepatitis.
- Cirrhosis: irreversible scarring of the liver.
Department of Health, 2016, gives which recommendations on alcohol consumption?
Do not regularly drink more than 14 units per week, spread evenly over 3 or more days and not more than 5 units per day.
Pregnant women should avoid alcohol completely.
Any level of alcohol consumption increases the risk of cancers, particularly breast, mouth and throat.
Which questioning technique can be used to screen for harmful alcohol use?
CAGE questions:
- Have you ever thought you should CUT down?
- Do you get ANNOYED at others commenting on your drinking?
- Do you ever feel GUILTY about drinking?
- Do you EVER drink in the morning to help your hangover or nerves?
The Alcohol Use Disorders Identification Test (AUDIT) is a questionnaire developed by WHO to screen people for harmful alcohol use.
What are the complications of chronic alcohol use?
- alcoholic liver disease
- cirrhosis
- hepatocellular carcinoma
- alcohol dependance and withdrawal
- Wernicke-Korsakoff syndrome
- pancreatitis
- alcoholic cardiomyopathy