Liver and Pancreas Lab Work

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Liver and Pancreas Lab Work

• Dr. Felix Hernandez M.D.

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Hepatic Function Tests

• Are used to asses the health, function and
  stability of the liver.
• All hepatocytes contain these enzymes within them
  and they are released into circulation once the
  hepatocytes are damaged.
• Includes Aspartate aminotransferase (AST),
  Alanine aminotransferase (ALT), Alkaline
  phosphatase, and Bilirubin

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Aspartate aminotransferase (AST)

• serum (AST, SGOT, GOT)
• 035 IU/L
• 00.58 mckat/L
• Physiologic Basis
• Intracellular enzyme involved in amino acid
  metabolism. Present in large concentrations in
  liver, skeletal muscle, brain, red cells, and
  heart. Released into the bloodstream when tissue
  is damaged, especially in liver injury.
• Interpretation
• Increased in Acute viral hepatitis (ALT gt AST),
  biliary tract obstruction (cholangitis,
  choledocholithiasis), alcoholic hepatitis and
  cirrhosis (AST gt ALT), liver abscess, metastatic
  or primary liver cancer right heart failure,
  ischemia or hypoxia, injury to liver ("shock
  liver"), extensive trauma. Drugs that cause
  cholestasis or hepatotoxicity.
• Decreased in Pyridoxine (vitamin B6) deficiency.
• AST/ALT ratio gt1 suggests cirrhosis in patients
  with hepatitis C.

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Alanine aminotransferase

• serum (ALT, SGPT, GPT)
• 035 U/L
• 00.58 mckat/L
• Physiologic Basis
• Intracellular enzyme involved in amino acid
  metabolism. Present in large concentrations in
  liver, kidney in smaller amounts, in skeletal
  muscle and heart. Released with tissue damage,
  particularly liver injury.
• Interpretation
• Increased in Acute viral hepatitis (ALT gt AST),
  biliary tract obstruction (cholangitis,
  choledocholithiasis), alcoholic hepatitis and
  cirrhosis (AST gt ALT), liver abscess, metastatic
  or primary liver cancer nonalcoholic
  steatohepatitis right heart failure, ischemia or
  hypoxia, injury to liver ("shock liver"),
  extensive trauma. Drugs that cause cholestasis or
  hepatotoxicity.
• Decreased in Pyridoxine (vitamin B6) deficiency.
• ALT is the preferred enzyme for evaluation of
  liver injury.

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Alkaline phosphatase

• serum
• 41133 IU/L
• 0.72.2 mckat/L (method- and age-dependent)
• Physiologic Basis
• Alkaline phosphatases are found in liver, bone,
  intestine, and placenta.
• Interpretation
• Increased in Obstructive hepatobiliary disease,
  bone disease (physiologic bone growth, Paget
  disease, osteomalacia, osteogenic sarcoma, bone
  metastases), hyperparathyroidism, rickets, benign
  familial hyperphosphatasemia, pregnancy (third
  trimester), GI disease (perforated ulcer or bowel
  infarct), hepatotoxic drugs.
• Decreased in Hypophosphatasia
• Alkaline phosphatase performs well in measuring
  the extent of bone metastases in prostate cancer.

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Bilirubin

• 0.11.2 mg/dL
• 221 mcmol/L
• Direct (conjugated to glucuronide) bilirubin
  0.10.4 mg/dL lt7 mcmol/L
• Indirect (unconjugated) bilirubin 0.20.7 mg/dL
  lt12 mcmol/L
• Physiologic Basis
• Bilirubin, a product of hemoglobin metabolism, is
  conjugated in the liver to mono- and
  diglucuronides and excreted in bile.
• Some conjugated bilirubin is bound to serum
  albumin, so-called D (delta) bilirubin.
• Elevated serum bilirubin occurs in liver disease,
  biliary obstruction, or hemolysis.
• Interpretation
• Increased in Acute or chronic hepatitis,
  cirrhosis, biliary tract obstruction, toxic
  hepatitis, neonatal jaundice, congenital liver
  enzyme abnormalities (Dubin-Johnson, Rotor,
  Gilbert, Crigler-Najjar syndromes), fasting,
  hemolytic disorders. Hepatotoxic drugs.
• Only conjugated bilirubin appears in the urine,
  and it is indicative of liver disease hemolysis
  is associated with increased unconjugated
  bilirubin.

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Pancreatic Enzymes

• Are used to determine the health and function of
  the pancreas and other areas of the GI system
• You measure the native enzymes that are produced
  by and released by the pancreas.
• They include
• Amylase
• Lipase

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Amylase

• serum
• 20110 U/L
• 0.331.83 mckat/L (laboratory-specific)
• Physiologic Basis
• Amylase hydrolyzes complex carbohydrates.
• Serum amylase is derived primarily from pancreas
  and salivary glands and is increased with
  inflammation or obstruction of these glands.
• Interpretation
• Increased in Acute pancreatitis (7095),
  pancreatic pseudocyst, pancreatic duct
  obstruction (cholecystitis, choledocholithiasis,
  pancreatic carcinoma, stone, stricture, duct
  sphincter spasm), bowel obstruction and
  infarction, mumps, parotitis, diabetic
  ketoacidosis, penetrating peptic ulcer,
  peritonitis, ruptured ectopic pregnancy,
  macroamylasemia. Drugs azathioprine,
  hydrochlorothiazide.
• Decreased in Pancreatic insufficiency, cystic
  fibrosis. Usually normal or low in chronic
  pancreatitis.
• Serum lipase is an alternative test for acute
  pancreatitis.

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Lipase

• serum
• 0160 U/L
• 02.66 mckat/L (laboratory-specific)
• Physiologic Basis
• Lipases are responsible for hydrolysis of
  glycerol esters of long-chain fatty acids to
  produce fatty acids and glycerol.
• Lipases are produced in the liver, intestine,
  tongue, stomach, and many other cells.
• Interpretation
• Increased in Acute, recurrent, pancreatic
  pseudocyst, pancreatic malignancy, peritonitis,
  biliary disease, hepatic disease, diabetes
  mellitus (especially diabetic ketoacidosis),
  intestinal disease, gastric malignancy or
  perforation, cystic fibrosis, inflammatory bowel
  disease (Crohn disease and ulcerative colitis).
• Serum lipase may be a more reliable test than
  serum amylase for the initial diagnosis of acute
  pancreatitis, due to an increased sensitivity in
  acute alcoholic pancreatitis and because lipase
  remains elevated longer than amylase.

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Lipase

• The specificity of lipase and amylase in acute
  pancreatitis is similar, though both are poor.
  Simultaneous measurement of serum amylase and
  lipase does not improve diagnostic accuracy.
  Measurement of serum lipase does not help in
  determining the severity or etiology of acute
  pancreatitis, and daily measurements are of no
  value in assessing the patient's clinical
  progress or ultimate prognosis.
• Test sensitivity is not very good for chronic
  pancreatitis or pancreatic cancer.

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Calcium

• serum (Ca2 )
• 8.510.5 mg/dL
• 2.12.6 mmol/L
• Panic lt6.5 or gt13.5 mg/dL
• Physiologic Basis
• Serum calcium is the sum of ionized calcium plus
  complexed calcium and calcium bound to proteins
  (mostly albumin).
• Level of ionized calcium is regulated by
  parathyroid hormone and vitamin D.
• Interpretation
• Increased in Hyperparathyroidism, malignancies
  secreting parathyroid hormonerelated protein
  (PTHrP) (especially squamous cell carcinoma of
  lung and renal cell carcinoma), vitamin D excess,
  milk-alkali syndrome, multiple myeloma, Paget
  disease of bone with immobilization, sarcoidosis,
  other granulomatous disorders, familial
  hypocalciuria, vitamin A intoxication,
  thyrotoxicosis, Addison disease. Drugs antacids
  (some), calcium salts, chronic diuretic use (eg,
  thiazides), lithium, others.

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Calcium

• Decreased in Hypoparathyroidism, vitamin D
  deficiency, renal insufficiency,
  pseudohypoparathyroidism, magnesium deficiency,
  hyperphosphatemia, massive transfusion,
  hypoalbuminemia.
• Need to know serum albumin to interpret calcium
  level. For every decrease in albumin by 1 mg/dL,
  calcium should be corrected upward by 0.8 mg/dL.