Chemical Pathology

Notes

  • Amylase is found in pancreatic, parotid and to a lesser degree fallopian tissue.
  • Amylase is useful in the investigation of acute pancreatitis but does have limited sensitivity and specificity. High amylase levels may also be seen in other gastrointestinal conditions.
  • If pancreatitis is suspected then serum LDH, CRP, calcium and albumin may be useful as prognostic indicators.
  • High serum amylase may be seen in macroamylasaemia and should be suspected if there is a raised serum amylase but no symptoms of pancreatic or parotid disease. Urine amylase may be useful in this situation.
  • Whilst serum amylase is raised in parotitis (mumps) to levels found in acute pancreatitis, the test has no application in the diagnosis or monitoring of this condition.
  • Urine amylase may be useful to investigate for possible macroamylasaemia (send with a simultaneous blood sample for amylase:creatinine clearance) but is not sufficiently accurate to distinguish acute pancreatitis from other intra-abdominal conditions that are associated with a raised serum amylase.

Sample requirements

For adults, blood taken into a 5mL gold top gel tube (or rust top for the Acute Unit)

5ml gold tube




For children, blood taken into a 3.5ml rust top tube:

3.5ml rust top tube




For neonates, blood taken into a 0.8mL lithium heparin tube minicollect tube:

Sample tube: pale green cap






Urine amylase:creatinine clearance for investigation of possible macroamylasaemia

Send paired blood and urine samples (samples "a" and "b" below) immediately to the laboratory for amylase:creatinine clearance (urine must reach the laboratory in less than 2 hours of collection).

a) Urine collected into a 30mL white top Sterilin container:

30ml universal container





b) blood taken into a 5mL gold top gel tube (or rust top for the Acute Unit):

5ml gold tube




Storage/transport

Send to the laboratory at ambient temperature as soon as possible. If unavoidable, and clinically appropriate, blood samples can be stored refrigerated overnight. Urine samples are less stable and must reach the laboratory in less than 2 hours of collection.

Required information

Relevant clinical details including surgery history e.g. post ERCP.

Turnaround times

The assays are run throughout the day and night.

The in-lab turnaround time is normally less than 24 hours.

The test can be ordered as an urgent request.

Reference ranges

Serum amylase: 28 - 100 U/L

Amylase:creatinine clearance:: 1-4 %

Further information

To learn more about amylase visit Lab Tests Online


Page last updated: 27/04/2021