Liver function
Haemotological regulation
Organ = metabolism
Gland = secretions
Phagocytosis and antigen
presentation
Metabolic regulation
Plasma protein synthesis
Carbohydrate
metabolism
Removal of circulating
hormones
Lipid metabolism
Removal of antibodies
Amino acid metabolism
Removal /storage of
toxins
De-toxification and
excretion
Bilirubin metabolism
Storage - vitamins [A, D,
B12], Cu, Fe
Bile production
Carbohydrate metabolism
Glycogenesis
Glycogenolysis
Gluconeogenesis
IMPAIRMENT
Hypoglycaemia
Glucose
Intolerance
http://static.howstuffworks.com/gif/diabetes-glucose-regulation.gif
Lipid Metabolism
•Lipoprotein synthesis
•Oxidation of fats
•Synthesis of cholesterol,
phospholipids
•Catabolism of steroids
IMPAIRMENT
Altered lipid profiles
2O Hyperaldosteronism
→↑BP ↓K ↑pH
2O Hypercorticolism =
Cushing’s disease
Gonadal dysfunction → ∆
oestrogen:testestorone
http://www.medscape.com/pi/editorial/clinupdates/2001/608/art-cu02.fig04.gif
Amino acid metabolism
•
Deamination and transamination of amino acids
•
Removal of ammonia
•
Synthesis of amino acids
Hepatic encephalopathy
IMPAIRMENT
Hypoproteinaemia
Source: seqcore.brcf.med.umich.edu/ mcb500/aametov.gif
Synthesis of hormones and plasma proteins…….
•
•
•
•
•
•
Insulin-like growth factor (IGF-1) → stimulated by pituitary growth hormone
Thrombopoietin → platelet production
Angiotensinogen (α-2-globulin) → hydrolysed by renin to angiotensin [reninangiotensin-aldosterone system (RAAS)]
Heparin
Albumin
Extrinsic pathway clotting factors →I (fibrinogen), II (Prothrombin), IV, V, VI, and VII
http://www.biosbcc.net/doohan/sample/images/blood%2520cells/clottingcascade
IMPAIRMENT
Clotting disorders, ↓ osmotic pressure
Bile production ….
Water
Bile Acids e.g. taurocholic
and glycocholic acid
Electrolytes
Cholesterol
Phospholipids
Bilirubin
IMPAIRMENT
• Malabsorption of fats
and fat soluble
vitamins
• Jaundice
http://sbsweb.bangor.ac.uk/images/bsx1016/sm_liver_position
Detoxification – refer to Biochemistry and PK done in years 2/3.
Phase I = modify
Phase II = conjugate
IMPAIRMENT
Reduced drug metabolism, reduced
protein binding of drugs
http://www.aspartame-detox.info/images/brain-01.jpg
Filtration – Reticuloendothelial system
Blood filtration,
phagocytosis of bacteria
and other particulate
matter
IMPAIRMENT
Exposure to bacteria
and other particles
Source :www.bu.edu/histology/ i/15204loa.jpg
Symptoms of liver disease
• Most symptoms non specific - anorexia, malaise,
fatigue, fever
• ↓ general health
• cirrhotic habitus = wasted extremities plus protuberant
abdomen with ascites
• Generalised pruritus (itchiness) – due to retention of
bile salts
• Xanthelasma (fat build up under skin surface),
xanthomas
• Pale stools – lack of bile
• Which of these is most specific?
akimichi.homeunix.netXanthom
a disappearance Document
272 x 324 pixels - 55k - gif
Disorders of coagulation/circulation
• ↑ bleeding and bruising
• ↑ prothrombin time (PT) →
extrinsic clotting pathway
(Prothrombin ratio (PR) and
international normalized ratio (INR)
are derived measures of PT).
• Thrombocytopaenia (↓platelets)
• Dysfibrinogenaemia (altered
fibrinogen function)
• Portal hypertension → endothelial
stretching and shear stress → ↑
NO → systemic vasodilation =
hyperdynamic circulation
• Hepatopulmonary syndrome =
pulmonary vasodilation → ↑blood
flow (ventilation-perfusion
mismatch) → arterial desaturation
• Cyanosis and clubbing →
enlargement of distal fingers and
toes. Due to vasodilation?
http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/18127.jpg
Liver disease?
http://upload.wikimedia.org/wikipedia/en/thumb/e/e0/Gollum.PNG/220px-Gollum.PNG
Other changes
• ↑ parotid salivary gland → fatty infiltation
• Gynecomastia (mammary gland development
in males), testicular atrophy, impotence
• Amenorrhoea (absence of menstrual period)
• Erythema (redness of skin) – build up of
unmetabolised wastes in body
http://www.sciencephoto.com/images/download_lo_res.html?id=771500153
Jaundice
• Icterus (icteric)
• Accumulation of
bilirubin =
hyperbilirubinaemia
• Skin, conjuctiva,
mucous membranes
• Dark urine from renal
excretion of bilirubin
http://www.modulomedico.com/fotos/imgJaundiceBig.jpg
Serum chemistry/diagnostic testing
Bilirubin
•Breakdown product of haemoglobin
•Globin = protein
•Heme = iron containing → biliverdin
(green bruising) → bilirubin → yellow
(bruising/bile)
•Bilirubin → conjugated with
glucuronides in liver
•Excreted in bile
•Can be measured in the unconjugated
(indirect) or conjugated (direct) form
•Relatively insensitive indicator of liver
disease
Source:web.indstate.edu/thcme/
mwking/hemedegradation.jpg
From Beckett - Lecture Notes : Clinical Biochemistry 7th ed 2005
From Swaminathan – Handbook of Clinical Biochemistry 2004
Aminotransferases (ALT and AST)
Transaminase enzymes (aminotransferases) → reversible
transfer of an amino group between two a-keto acids.
• Alanine aminotransferase = liver cytosol (ALT)
• Aspartate aminotransferase = liver and other tissues (AST)
• Reasonably sensitive indicators of liver disease, ALT >> AST
Source: http://www.np.edu.sg/~dept-bio/biochemistry/aab/topics/asptrans.gif
Alterations in ALT and AST
Mild elevations(<100U/L)
•
Fatty liver/non-alcoholic steatohepatitis (fatty degeneration)
•
Chronic viral hepatitis
Moderate elevations(100-300 U/L)
•
Acute or chronic hepatitis
•
Alcoholic hepatitis
•
Mild/moderate inflammation
High elevated(>300 U/L)
•
Acute viral hepatitis
•
Hepatic necrosis → drugs or toxins
•
Ischemic hepatitis /circulatory shock. VALUES CAN BE 500-1500 U/L
•
Values >3000 U/L- toxic necrosis, or severe hypoxia
AST/ALT ratio
•
•
•
Significant overlap between different conditions BUT
> 2 suggestive alcoholic liver disease (if ALT < 500 U/L)
< 1 viral hepatitis can ↑ratio as fibrosis and cirrhosis develop
Alkaline phosphatases (ALP)
•ALP = hydrolase →removes phosphate groups
•Present in bile canaliculi, bone and placenta
•↑ sensitivity for hepatobiliary disease
•↓ specificity for hepatobiliary disease
•Due to its numerous isoenzymes, its presence in nonhepatic tissues, and its sensitivity to drug induction
Increases in liver ALP
• Cholestasis, cholecystitis, cholangitis, cirrhosis,
hepatitis, fatty liver, liver tumour, liver metastases,
drug intoxication
• Drugs e.g. verapamil, carbamazepine, phenytoin,
erythromycin, allopurinol, ranitidine
• ↑ → enhanced synthesis rather than hepatocytic
leakage
• ↓ ≠ clinically significant
• If source ↑ ALP is not clear check other liver enzymes
Gamma glutamyl transpeptidase (GGT)
• GGT → hydrolysis of gamma-glutamyl peptide
bonds
• Biliary enzyme → obstruction of biliary tract +
damage to biliary capillaries
• Easily induced (alcohol, drugs) →
disproportionately ↑ in alcoholic liver disease
• Can be elevated in other diseases e.g. CHD, MI,
COPD, pancreatitis, renal disease
Patterns of enzyme alterations
ALT
Hepatocellular
≥ 2x upper
limit of normal
Cholestasis
Normal
(bile flow
obstruction)
Mixed disease
↑
ALP
Normal
ALT/ALP ratio
≥5
≥ 2x ULN
≤2
↑
2-5
Ramachandran and Kakar J Clin Pathol 2009;62;481-492 Histological patterns in
drug-induced liver disease
ERCP = Endoscopic Retrograde Cholangiopancreatography From Beckett - Lecture Notes : Clinical Biochemistry 7th ed 2005
From Beckett - Lecture Notes : Clinical Biochemistry 7th ed 2005
Other tests
•
Haematology (anaemia, RBC parameters)
•
Clotting tests (PT) NOTE – these are vitamin K-dependent clotting factors
•
•
•
Lipid tests (total cholesterol, HDL, LDL, triglycerides)
Biochemistry (albumin, glucose)
Serology
-Hepatitis virus
-Antimitochondrial antibody (present in >90% of biliary cirrhosis cases)
-Antinuclear factor- inflammatory marker
-Antismooth muscle antibody-inflammatory marker
-Alpha fetoprotein-hepatic carcinoma marker
•
Functional tests
-Clearance tests (caffeine, bromosulphthalein), Elimination tests (galactose)
•
Imaging procedures
-Abdominal radiographs
-US, NMR, CT
-Direct biliary visualisation → contrast studies
•
Liver Biopsy
-
Percutaneous
-Surgical
Drug Induced Liver Disease (DILD)
• > 1000 drugs → DILD
• ↑Hz drug withdrawal from the market
Reference Hughes et al. Use of laboratory test data: a process guide and
reference for health care professionals. 2nd Ed, PSA, 2009.
Drug Induced Liver Disease (DILD)
• Consider wherever altered liver function
tests
• However
– Broad range of drugs
– Wide variation in hepatic injury caused
Drug Induced Liver Disease (DILD)
• Types of hepatic injury
–
–
–
–
–
–
Hepatitis
Cholestasis
Mixed
Fibrosis
Granulomatous lesions
Neoplasms
http://www.health-writings.com/img/mk/drug-induced-liver-disease/drugs_MIC062ML.jpg
Drug induced hepatic failure
http://www.path.cam.ac.uk/Normal/AR_Alimentary/LV_Liver/N_AR_LV_02.jpg
http://mayoresearch.mayo.edu/mayo/research/nyberg_lab/images/histology.jpg
Drug Induced Liver Disease (DILD)
•
•
•
•
•
Other changes (functional)
Enzyme induction and inhibition
Dietary /other deficiencies e.g. cysteine, Vit K
Steatosis = fatty change
Phospholipidosis
Drug Induced Liver Disease (DILD)
• Intrinsic
– Dose related
– Occurs within few days of use
– Related to drug or toxic metabolite of drug
– Known/reported/expected
• Idiosyncratic
– Unexpected
– Variable latency
– Not usually dose related
Intrinsic - usually dose related:
Drug
Reason
Paracetamol
Hepatocellular necrosis
Amiodarone
Chronic steatosis- due to total dose
over time
Cyclosporine
Cholestasis due to toxic serum levels
Methotrexate
Elevated aminotransferase and fibrosis
after single large dose
Niacin
Vascular injury after prolonged
administration
Oral Contraceptives
Hepatic tumour after prolonged
administration
Tetracycline
Steatosis after large total dose and
renal dysfunction
Idiosyncratic - usually hypersensitivity
Drug
Reason
Isoniazid, diclofenac, nefazodone,
trazodone, venlafaxine etc
Hepatocellular necrosis
CPZ, oestrogen, macrolides
Cholestasis
Phenytoin, sulphamethoxazole
Immune reaction
Diltiazem, sulphonamides
Granulomatous Hepatitis
Didanosine, tetracycline, valproic
acid
Steatosis
Methotrexate
Fibrosis
Amoxycillin/Clavulonic Acid
Cholestatic injury
Factors affecting DILD
•
•
•
•
•
•
•
•
•
Age
Gender
Genetic factors
Nutritional status
Renal function
Dose and duration
Alcohol
Cigarette smoking
Other conditions- Hep C, HIV, RA
Paracetamol toxicity
• Paracetamol = #1 drug → calls to poisons information centres
in Australia and NZ. 1
• Paracetamol = #1 drug overdose → hospital presentation and
admission. 2,3
• Hepatic failure and death → uncommon outcomes
• #1 cause of acute fulminant hepatic failure in Western
countries.4
1. Buckley N, Eddleston M. Paracetamol (acetaminophen) poisoning. Clin Evid 2005; (14): 1738-1744.
2. Dart RC, Erdman AR, Olson KR, et al. Acetaminophen poisoning: an evidence-based consensus guideline for out-of-hospital
management. Clin Toxicol (Phila) 2006; 44: 1-18.
3. Linden CH, Rumack BH. Acetaminophen overdose. Emerg Med Clin North Am 1984; 2: 103-119.
4. Ostapowicz G, Fontana RJ, Schiødt FV, et al. Results of a prospective study of acute liver failure at 17 tertiary care centers in
the United States. Ann Intern Med 2002; 137: 947-954.
Phases of paracetamol hepatotoxicity
PHASE 1 (0-24 H)
•Asymptomatic
•Anorexia
•Nausea or vomiting
•Malaise
•Subclinical rise in serum transaminases
levels begins at about 12 hours
postingestion
PHASE 3 (72-96 H)
•Centrilobular hepatic necrosis with continued
abdominal pain
•Jaundice
•Coagulopathy
•Hepatic encephalopathy
•Nausea and vomiting
•Renal failure
•Fatality
PHASE 2 (18-72 H)
•Right upper quadrant abdominal pain,
anorexia, nausea, vomiting
•Continued rise in serum transaminases
levels
•Admitted to hospital
PHASE 4 (4 D TO 3 WK)
•Complete resolution of symptoms
•Complete resolution of organ failure
Paracetamol toxicity
• Toxicity when GSH
reserves
overwhelmed by
N-acetyl-pbenzoquinone
imine (NAPQi)
• ± gastric lavage
and activated
charcoal
• Treatment → IV
N-acetylcysteine
http://drugdiscoveryopinion.com/images/paracetamol_metabolism.jpg
Management plan- dose thresholds for
NAC treatment
≠ serum readings <4 hours of poisoning
Frank F S Daly, John S Fountain, Lindsay Murray, Andis Graudins and Nicholas ABuckley(2008).Guidelines for the management of
paracetamol poisoning in Australia and New Zealand — explanation and elaboration. A consensus statement from clinical toxicologists
consulting to the Australasian poisons information centres. MJA 2008; 188 (5): 296-302.
Management Plan
Source- Frank F S Daly, John S Fountain, Lindsay Murray, Andis Graudins and Nicholas ABuckley(2008).Guidelines for the
management of paracetamol poisoning in Australia and New Zealand — explanation and elaboration. A consensus statement from
clinical toxicologists consulting to the Australasian poisons information centres. MJA 2008; 188 (5): 296-302.
Source: Frank F S Daly,
John S Fountain, Lindsay
Murray, Andis Graudins
and Nicholas A
Buckley(2008).Guidelines
for the management of
paracetamol poisoning in
Australia and New Zealand
— explanation and
elaboration. A consensus
statement from clinical
toxicologists consulting to
the Australasian poisons
information centres. MJA
2008; 188 (5): 296-302.
Source: Frank F S Daly, John S Fountain,
Lindsay Murray, Andis Graudins and
Nicholas A Buckley(2008).Guidelines
for the management of paracetamol
poisoning in Australia and New Zealand
— explanation and elaboration. A
consensus statement from clinical
toxicologists consulting to the
Australasian poisons information
centres. MJA 2008; 188 (5): 296-302.
Source- Frank F S Daly, John S Fountain, Lindsay Murray, Andis Graudins and Nicholas ABuckley(2008).Guidelines for the
management of paracetamol poisoning in Australia and New Zealand — explanation and elaboration. A consensus statement from
clinical toxicologists consulting to the Australasian poisons information centres. MJA 2008; 188 (5): 296-302.
Management Plan cont…
Management Plan cont…
• Monitoring of liver function
• Post –discharge patient education
• Referral to Psychologist if needed
Kava (Piper methysticum)
• Kava = plant native to South Pacific Islands
• Western society → herbal remedy anxiety
• Kavalactones = active components
-6 KL ~ 95% of the activity
• Anxiolytic effect ~ benzodiazepines
-few side effects
-limited cognitive and motor impairment
• Kava → hepatotoxicity e.g. hepatitis, cirrhosis,
fulminant liver failure, death
• Banned in many countries
• Australia → voluntary recall 2002
Isolated Perfused Rat Liver (IPRL)
PUMP
Perfusate
• Kavalactone
• 95% O2/5% CO2
• Taurocholic acid
• Krebs-Henseleit
(KH) buffer
Inferior
Vena
Cava
Hepatic
Portal Vein
37°C
10 µg/mL Kavain for 2 hours is
hepatotoxic in IPRL studies
Light Microscopy
Scanning Electron Microscopy
Control Liver
Following Kavain Treatment
Fu (2008) World J Gastroenterology 14: 541546
Membranes and electron
dense structures
Distorted cell nuclei
Autophagosome
Whirled ER surrounding
mitochondrion
Advice for case studies
• Common things occur commonly.
• Uncommon things don’t.
• When you have eliminated the impossible,
whatever remains, however improbable, must
be the truth.
Sherlock Holmes - The Sign of the Four (1890)
Case Study #1 – history and signalment
•
•
•
•
•
•
68 YO male retired labourer
Lethargy but no pain
BW ↓19kg in the last 3 months
Eating normally up to last 3 weeks
Dark urine and pale stools
‘Moderate’ drinker throughout lifetime
Clinical findings
• Jaundice
• Weakness
• Palpable, non-tender mass in upper RHS
abdominal quadrant
Serum chemistry
•
•
•
•
Analyte
Result
Reference Range
Units
Albumin
32
36-47
g/L
ALP
632
40-125
U/L
ALT
55
10-40
U/L
Total bilirubin
90
2-17
µmol/L
GGT
200
10-55
U/L
Bilirubin predominantly conjugated
↑↑ ALP and GGT
Predominantly cholestasis
Pancreatic tumour obstructing common bile duct
Case Study #2 – history and signalment
•
•
•
•
21 YO female student
Flu-like symptoms for 2 days
Condition deteriorating – dark urine, vomiting
Recently returned from long holiday in Asia
Clinical findings
• Jaundice
• Temperature 38.6oC (36.5-37.5 oC)
• Liver enlarged and tender
Serum chemistry
•
•
•
•
•
Analyte
Result
Reference Range
Units
Albumin
40
36-47
g/L
ALP
190
40-125
U/L
ALT
560
10-40
U/L
Total bilirubin
110
2-17
µmol/L
GGT
60
10-55
U/L
Bilirubin predominantly conjugated
↑↑ ALT
Predominantly hepatocellular
Any other tests?
Serology - high Hepatitis A titre
Case Study #3 – history and signalment
•
•
•
•
48 YO male gardener
Fatigue
BW ↓8 kg over last 4 months
Denies any history of hepatitis, alcohol use,
family history of liver disease, exposure to
hepatotoxins
Clinical findings
• No abnormalities detected
Serum chemistry
•
•
•
•
Analyte
Result
Reference Range
Units
Albumin
20
36-47
g/L
ALP
56
40-125
U/L
ALT
16
10-40
U/L
Total bilirubin
13
2-17
µmol/L
GGT
24
10-55
U/L
Any other tests?
PT = 18 s (10-13 s)
IM dose 10 mg Vitamin K returned PT to 12 s < 48 hours
Serology and endoscopy → Coeliac disease → interfering
with Vit K and protein absorption
Case Study #4 – history and signalment
• 13 YO male
• Muscle pain and feeling hot for 2 days
• Eaten little over this time
Clinical findings
• Jaundice
• Temperature 38.3oC
• No abdominal pain or swelling
Serum chemistry
•
•
•
•
•
•
•
•
•
Analyte
Result
Reference Range
Units
Albumin
45
36-47
g/L
ALP
180
40-125
U/L
ALT
30
10-40
U/L
Total bilirubin
60
2-17
µmol/L
GGT
35
10-55
U/L
Bilirubin 90% unconjugated
Any other tests?
Haematology – RBC and reticulocyte count normal
Gilbert’s syndrome = most common hereditary hyperbilirubinaemia
Familial autosomal dominant in 2-3% men
↓ activity of the glucuronyltransferase → ↓ bilirubin conjugation
Exposed by caloric restriction while ill with cold
↑ ALP but GGT normal ??
Raised ALP from bone turnover with onset of puberty
Case Study #5 – history and signalment
•
•
•
•
•
36 YO female lawyer
Very stressful job
Working 12 hour days striving for promotion
Feeling run down
Annual blood test
Clinical findings
• No abnormalities detected
Serum chemistry
•
•
•
•
Analyte
Result
Reference Range
Units
Albumin
42
36-47
g/L
ALP
130
40-125
U/L
AST
180
8-42
IU/L
ALT
70
10-40
U/L
Total bilirubin
15
2-17
µmol/L
GGT
380
10-55
U/L
Any other tests?
Haematology – leukopaenia (↓WBC), macrocytosis (↑MCV)
Toxic effects on bone marrow?
Finally admits drinking one bottle wine per day over lunch and after
work
• Quit job. Quit drinking
• 3 months later – ALT 28 IU/L, GGT 50 IU/L, ALP 54 IU/L
Case Study #6 – history and signalment
• 26 YO male
• Admitted to hospital with 5-day history of
excruciating abdominal pain radiating up back
• Patient reports persistent nausea and
vomiting
Clinical findings
• Vital stable signs on admission
• No fever
• Extreme reaction to abdominal palpation
Serum chemistry
•
•
•
•
•
•
Analyte
Result
Reference Range
Units
Albumin
34
36-47
g/L
ALP
110
40-125
U/L
ALT
24
10-40
U/L
Total bilirubin
16
2-17
µmol/L
GGT
23
10-55
U/L
Any other tests?
Blood test normal
Serum amylase normal
US and CT normal
Requested ongoing opiates for pain control
Opiates withdrawn → patient checked out → continue search for
opiates elsewhere
Summary
•
•
•
•
•
•
•
•
•
Variable interspecies anatomy
Histological structure open to interpretation
Metabolic functions (glucose, protein, fat)
Glandular function (produces bile)
Jaundice = hyperbilirubinaemia
Bilirubin is a product of heme catabolism
Pre-hepatic (unconjugated)
Hepatic (unconjugated + conjugated – glucuronic acid)
Cholestatic/obstructive → intra/post-hepatic
(conjugated)
• Diagnosis – symptoms, laboratory, imaging, biopsy
Any Questions?