Pancreatic Biochemistry Tests Flashcards
Alpha amylase is only present in the pancreas. T/F?
False it is present as an isoenzyme in other tissues such as the salivary glands, testes, fallopian tubes and lungs
How will acute pancreatitis affect serum amylase concentrations?
There will be a severe elevation of serum amylase levels
In acute pancreatitis serum amylase rises within 5-8 hours of the onset of symptoms. When does this normalise?
By day four
Other than acute pancreatitis, why might serum amylase be raised?
Ruptured ectopic pregnancy Salivary gland lesion Renal insufficiency DKA Tumours Drugs Macroamylase
What is macroamylase and why is it significant?
Macroamylase is when amylase becomes bound to IgG or IgA and so cannot be filtered through the kidney and gives an effect ‘false’ high amylase level
How can macroamylasaemia be discounted?
By testing urine amylase
Serum lipase rises in acute pancreatitis with 4-8 hours of onset of symptoms. When does this normalise?
Within 8-14 days
What test is the gold standard of invasive pancreatic function tests and what does the test involve?
Secretin pancreozymin test - measure pancreatic enzyme (trypsin) in the duodenum aspirate over two hours
Why is faecal chymotrypsin not generally used as a pancreatic function test?
Because of lack of standardisation of results between laboratories
What pancreatic function test is used particularly as a marker of pancreatic insufficiency?
Faecal elastase
If a patient had a high serum amylase but low urine amylase with normal serum lipase and faecal elastase what might be the diagnosis?
Macroamylase
If a young, female patient had a high serum and urine amylase but with normal serum lipase and faecal elastase what might be the diagnosis?
Ruptured ectopic pregnancy
If a patient had a high serum and urine amylase, high serum lipase and with normal faecal elastase what might be the diagnosis?
Acute pancreatitis
