- Amylase & lipase are enzymes derived from pancreatic acinar cells
- Both have their own advantages
- Where possible lipase is recommended as the assay of choice
Amylase
- Serum amylase remains most commonly used in clinical practice
- Diagnosis suggested when level is greater than 3x upper range of normal (>300 IU/L)
- Less accurate than lipase for diagnosis:
- May remain within normal levels in as many as one fifth of patients
- Levels rise quickly and have a serum half life of 2 hours - a single peak in amylase may be missed
- Non-specific and may be elevated due to other causes
- Level of elevation does not necessarily correlate with disease severity or prognosis
Lipase
- Diagnosis suggested when level is greater than 600 IU/L
- Greater overall accuracy than amylase
- Recommended as assay of choice by BSG
- More sensitive and specific for diagnosis
- Concentrations are increased for up to 14 days after onset of pancreatitis