Investigations
Blood Tests:
Liver function: Serum Albumin: marker of synthetic function; indicates severit
albumin = bad prognostic sign. Prothrombin time (PT): marker of synthetic fu
of acute and chronic liver disease. VitK def should be excluded as cause of pro
vit K. VitK def commonly occurs in biliary obstruction, as low conc of bile salts
Liver Biochemistry:
- Bilirubin: liver disease - often get inc se bilirubin with other abnormalitie
Liver/ Biliary Tract Anatomy + Function
between conjugated and unconjugated bilirubin is necessary in congenita
Liver = largest internal organ in body; situated in right hypochondrium. Divided into left and
to exclude haemolysis
right lobes by middle hepatic vein. Right lobe = larger; contains caudate and quadrate lobes.
- Aminotransferases = transaminases: contained in hepatocytes and leak in
Further divided into 8 segments by divisions of right, middle and left hepatic veins.
Alanine aminotransferases (ALT): reflects hepatocellular damage: liver-sp
Blood supply to the liver = 25% of resting cardiac output; via two main vessels, both enter liver
disease. Aspartate aminotransferase (AST): high levels seen in hepatic ne
via hilum (porta hepatitis): hepatic artery: branch of coeliac axis; 25% total blood flow.
Phosphatase (ALP): raised in both intra- and extra-hepatic cholestatic dis
Autoregulation of blood flow ensures constant total liver blood. The portal vein: drains most of
synthesis. In cholestatic jaundice, may be 4-6x normal limit. Raised levels
GIT and spleen. Supplies 75% of blood flow. Normal portal pressure is 5-8mmHg; post-prandial
(e.g. mets) and cirrhosis, frequently in absence of jaundice. Gamma-Gluta
flow increase. Blood from these vessels is distributed via portal tracts into sinusoids. Blood
cholestasis: increases with fatty liver disease, alcohol intake and cholesta
leaves sinusoids and enters branches of hepatic vein, which join into three main branches
- Total Proteins
before entering the IVC
Viral markers
Lymph formed mainly in perisinusoidal space; collected in lymphatics present in portal tracts.
Hematological:
These small lymphatics enter larger larger vessels which eventually drain into the hepatic ducts.
• FBC –anaemia?; RBCs often macrocytic and can have abnormal shapes du
Functional unit of liver = acinus; = parenchyma supplied by smallest portal tracts, containing
VitaminB12: normal of high. Folate often low due to poor dietary intake.
portal vein radicles, hepatic arterioles and bile ductules. Hepatocytes near this triad (zone 1) are
• Bleeding à hypochromic, microcytic picture
well supplied with oxygenated blood + more resistant to damage than cells nearer terminal
• Alcohol —> macrocytosis (sometimes with leucopenia + thrombocytopen
hepatic (central) veins.
• Hyperspenism results in pancytopenia
Biliary system: bile canaliculi form network between hepatocytes. Join to form thin bile
• Cholestasis can produce abnormal-shaped cells, and vitK deficiency.
ductules near portal tract, which enter bile ducts in portal tracts. These combine to form R&L
• Haemolysis may accompany acute liver failure and jaundice.
hepatic ducts which leave each liver lobe. Hepatic ducts join at porta hepatitis to form common
• Aplastic anaemia occurs in up to 2% patients with acute viral hepatitis.
hepatic duct. Cystic duct connects GB to lower end of common hepatic duct. GB lies under right
• Raised serum ferritin with transferrin saturation (>60%) seen in hereditar
lobe of liver: stores and concentrates hepatic bile; capacity approx 50mL. CBD = formed at
Biochemical
junction of cystic and common hepatic duct; <8mm in diameter, passing through head of
• a1-antitrypsin: deficiency can —> cirrhosis
pancreas, narrowing at its lower end to pass into duodenum.
• a-Fetoprotein: normally produced by fetal liver: reappearance in increasi
CBD and pancreatic duct open into duodenum; CBD and pancreatic duct open into D2, most
hepatocellular carcinoma. Blood levels slightly raised with regenerative li
commonly through common channel at Ampulla of Vater: contains muscular sphincter of Oddi:
liver disease and chronic liver disease or teratomas.
contracts rhythmically; prevents bile entering duodenum, by maintaining higher pressure than
• Wilson’s disease: raised urinary copper, low serum copper and caerulopl
GB in fasting state.
Immunological tests
• Serum immunoglobuins: inc gamma-globulins from reduced phagocytosi
Functions of the Liver absorbed antigens. These antigens then stimulate antibody production in
Protein Metabolism: Synthesis and Degradation. Liver receives amino acids from intestine and and plasma cell infiltrates.
muscles, and by controlling the rate of gluconeogenesis and transamination, regulates plasma • Primary biliary cirrhosis = predominantly raised serum IgM
levels. Albumin: t1/2 16-24 days; 10-12g synthesised daily. Main function: control colloid • Autoimmune hepatitis = predominantly raised serum IgG: IgG4 useful in
osmotic pressure; transport water insoluble substances e.g. bilirubin, hormones, FAs and drugs. Serum antibodies
Hypoalbuminaemia: seen in chronic liver disease and malnutrition. Carrier proteins made in • AMA: anti-mitochondrial antibody: found in serum in >95% those with pr
liver (e.g. transferrin, caeruloplasmin). Liver produces coagulation factors: fibrinogen, • Nucleic, smooth muscle (Actin), liver/kidney microsomal AB : can be foun
prothrombin, factors V, VII, IX, X, CIII, proteins C and S and antithrombin, as well as complement with AI hepatitis (but not specifically: also in other AI disorders and other
system components. Liver stores large amounts of vitamins (Vit A, D, B12, K, folate, iron, • ANCA: anti-nuclear cytoplasmic antibodies: found in serum of pt with pri
copper). Degradation of AA by transamination and oxidative deamination to produce ammonia; Genetic Analysis: Haemochromatosis (HFE gene) and a1-antitrypsin deficiency
this is converted to urea to be excreted by the kidneys. Urine tests: bilirubin + urobilinogen
Carbohydrate Metabolism: Glucose homeostasis and maintenance of blood sugar = major Bilirubinuria = due to presence of conjugated (soluble) bilirubin: found in pr w
function of the liver. Liver stores approx 80g glycogen. disease, but is absent if unconjugated bilirubin = major cause of jaundice.
Lipid metabolism: Liver metabolises lipoproteins (transport form of fats; insoluble in water); Presence of urobilinogen in urine = suggestive of haemolysis or hepatic dysfu
synthesises vLDLs and HDLSs. HDLs = substrate for LCAT, required to catalyse conversion of free Imaging techniques: define gross anatomy
cholesterol to cholesterol ester. Hepatic lipase removes TG from IDLs to produce LDLs, which are - US: non-invasive, safe, rel cheap. Analysis of reflected US beam detected
degraded by liver after uptake by specific cell-surface receptors. Altered lipoprotein metabolism liver appears as relatively homogenous structure. GB, CBD, pancreas, por
à alters membrane structures à red cell abnormalities (Seen in chronic liver disease) visualised. Abdo US useful in: jaundiced pt, hepatosplenomegaly/ spleno
Bile formation and secretion: Bile acid formation in hepatocytes from cholesterol. Bile acid liver disease (lesions >1cm); general parenchymal liver disease, assessing
uptake req for bile formation. Bile acids act as detergents = req for lipid solubilisation: form enlargement
micelles for fat absorption. Liver disease à no bileàno micelle formationà malabsorption and - Colour Doppler US: demonstrates vascularity within a lesion + direction o
failure to absorb fat dependent vitamins (vitA, D, K). - US contrast agents: mostly based on production of micro—bubbles withi
Bilirubin metabolism: Bilirubin produced mainly from breakdown of mature RBC by Kupffer vascularity, allowing detection of abnormal circulation within liver nodul
cells in the liver and RES; 15% bilirubin. RBC breakdown: Iron and globin are removed from - Hepatic stiffness (transient elastography): using US transducer, vibration
harm and reused. Haem à bilverdin which is then reduced à bilirubin. Bilirubin produced = passed through the liver, the velocity of which correlates with hepatic sti
unconjugated and water-insoluble; transported to liver bound to albumin; bilirubin dissociated worsening fibrosis. Can’t be used if ascites/ morbid obesity; is affected by
from albumin and is taken up by hepatic cell membranes and transported to ER. Bilirubin - Endoscopic US (EUS): EUS probe incorporated into tip of endoscope. High
conjugated with glucuronic acid and excreted into bile. Conjugated bilirubin = water-soluble; tumours of pancreas. EUS-guided FNA of tumours provided cytological/ h
actively secreted into biliary canaliculi and excreted into intestine within bile. Terminal ileum: malignancy. EUS also used to place transmural tubes to drain pancreatic
bacterial enzymes hydrolyse conjugated bilirubin, releasing free bilirubin. Some bilirubin - CT: characterisation of lesion +vascular supply. Visualisation of size, shap
reduced to urobilinogen, some of which is secreted into stools as stercobillinogen. Remainder LN and lesions in porta hepatis. Guidance for biopsy.
absorbed by terminal ileum and passed into liver via entero-hepatic circulation and re-excreted - MRI: most sensitive investigation of focal liver disease
as bile. Urobilinogen bound to albumin enters circulated and excreted in urine via kidneys. - MRCP: non-invasive; replacing ERCP. Used when biliary lesion present on
Hepatic excretion of conjugation impaired à small amount urobilinogen strongly bound to high-quality images of ductal anatomy
albumin à not excreted by kidneys à hyperbilirubinogen - Plain xrays of abdo: may show: gallstones (10% contain enough Ca to be
Hormone and Drug Inactivation: Liver catabolises hormones e.g. insulin, glucagon, oestrogens, instrumentation, surgery or fistula between intestine + GB; Pancreatic ca
GH, glucocorticoids and PTH. Primary site for drug and alcohol metabolism. Fat-soluble drugs porcelain GB
converted to water-soluble substances, facilitating their excretion in bile/urine - Radionucleotide imaging (scintiscanning): mainly used for dg of acute ch
Immunological function: Bacterial/other antigens which are transported to liver via portal vein atresia/ hepatitits in neonatal period.
from GIT are phagocytosed and degraded by Kupffer cells. These are part of innate immune - Endoscopy: Upper GI endoscopy; used for dg and Rx of varices, detection
system and secrete interleukins, TNF, collagenase and Lysosomal hydrolases. and for associated lesions, e.g. peptic ulcers. Colonoscopy may show por
endoscopy can identify small intestinal varices.
- ERCP: outlines biliary + pancreatic ducts. Inv passage of endoscopy into D
S&S of Liver Disease Contrast injected. Therapeutic ERCP: removal of CBD stones; stenting of b
Symptoms: amylase after ERCP; pancreatitis = most common complication.
- Acute liver disease: may be asymptomatic/ anicteric (no jaundice). Symptoms: often viral; - Percutaneous transhepatic cholangiography (PTC): under LA, fine needle
generalised – malaise, anorexia, fever. Jaundice as illness progresses slowly until identify biliar radicle, then further inject contrast to outline w
- Chronic liver disease: right hypochondrial pain (liver distension); abdo distension (ascites); ducts, success rate near 100%. PTC performed if ERCP fails
ankle swelling (fluid retention); haematemesis and melaena from GI hhge; pruritis - Angiography: selective cathterisation of coeliac axis + hepatic artery. Out
(cholestasis); breast swelling, loss of libido, menorrhea due to endocrine dysfunction. vasculature of hepatic tumours.